Choosing a Battery

CapnLoki wrote: ↑

Thu Jul 11, 2019 7:10 pm

Yup, its just that simple!

As for the fuse, its mainly to protect the wiring so its sized for the gauge of the wire, as it should be given that you don't know what your load will be. If you knew there was some other upper limit you could reduce the fuse appropriately. BTW, the 400 watt inverter could easily have a 40 to 50 amp load (or more) so bring extra fuses! Don't be tempted to increase the fuse size as it is close to maxed for the wire.

You don't mention charging - I like using the BatteryTender quick connects; you can also use the cigarette socket plug. I don't like alligator clips - they are an accident waiting to happen.

Ah forgot about the charging.

I'll need to go with these then, like I have on my other battery:
https://www.amazon.com/Battery-Tender-0 ... 000NCOKZQ/
https://www.amazon.com/gp/product/B0041CDPQO

The one thing that does concern me is that the cigarette lighter connection on the inverter is only good up to 150W and then you have to use the alligator clips on the inverter. From what I can tell I should be fine with the cellphones, Bluetooth speaker and pump for mattress inflation (the pump is 110V-120V and 0.6 amp, which if I am calculating correctly should be 88 - 104 Watts) at least for this trip on not having to use the alligator clips, but something I'll need to keep in mind for future, as I would also like to avoid alligator clips if possible.

bbergin76 wrote: ↑

Thu Jul 11, 2019 6:05 pm

Lane101 wrote: ↑

Fri Jun 14, 2019 11:45 am

Hi Bbergin 76,

The ExpertPower 12200 battery terminals work well with O-Ring adapter connectors; mine are hooked up that way. Just screw the connectors on. Note that my battery packs use o-ring connectors that are smaller than those on the Deltran (custom spliced 12 awg wire with Anderson Pole connectors on the other end) for both of my battery packs. The M5 bolts on the 1200 battery are 5mm across while the Deltran connectors are 3/8" (approx. 9.5 mm). You will need to check if a wider washer to hold the connectors securely. Once connected any exposed connections should be covered with electrical tape for added safety. Be careful when connecting wires to the battery terminal. A battery of this size can generate over 200 amps in a short circuit (even more for a full U1 size). I typically keep one terminal covered with electrical tape when making direct to battery connections. If you to the multiple battery route (one U1 and a second half-U1 size) you should by an extra Deltran SAE/O-ring connector so you don't have to deal with exposed terminals while camping.

Note, if you are referring the the Mighty Max U1 35ah battery the O-rings should also work. You may need to purchase connection hardware for this one (nuts, bolts and locknut washers). Again need to match hardware size to O-rings and battery terminals. One of my original half-U1 batteries had terminals like this.

U1 is a battery size. The Exp12200 and similar 18 - 22 amp hour batteries are often referred to as Half-U1 size. Note that while the Exp12200 specifications allow charging at up to 6 amps per hour it is more optimal to keep the charging rate below 4 amps/hour (referred to as .2 of Capacity or "C"). Would recommend the 3 amp charger as ideal if you also have a separate U1 battery.

Absolutely stick with AGM batteries for camping. They are the safest lead-acid type battery and the only type that does not vent gasses unless damaged or overcharged. Both Gel and flooded lead-acid require venting (source Battery University @ batteryuniversity.com). AGM is the only type I would use indoors or in a tent. Also, you can use 80% of an AGM battery's capacity versus a max of 50% of a flooded batter without damaging it.

P.S. Regarding Goofproof's comment. It is correct, we are seeking to protect both the device and the wiring from a current overload and one size often doesn't fit all. In your specific case, for charging with a Deltran Battery Tender (3 amp or less) and use of a Dreamstation, a 7.5 amp should protect both the CPAP, charger and wires given that it is the specified/provided fuse for the Deltran and below the 8 amps provided in the Dreamstation DC connector.

Good example of Goofproof's point is my set up (more complex with an inverter and solar power) where I use a 15 amp fuse on a 12 awg main battery connector with lower capacity fuses for the various items (bespoke Anderson pole connector for each that plugs into the main battery cable) in my modular system including:

- 5 amp fuse for my CPAP machines - 18 awg with barrel connector for CPAP with Anderson connectors for battery connection
- 7.5 amp fuse for the 3 amp Deltran charger - use the connector provided by Deltran, cut off the O-rings and spliced on the Anderson connectors
- 5 amp fuse for the solar panel wire (cable connects to solar charge controller)
- 7.5 amp fuse on my NOCO cigarette lighter socket (use to charge phones with a USB charger in the socket and to run our air mattress inflater)
- no additional fuse for the 400 watt inverter - 15 amp main cable fuse is more than sufficient as I want to cap the power draw to 180 watts given the size of my batteries. Also the inverter has its own fuses.

My system evolved over time. Started with just an 18 awg barrel connector cable for my CPAP with just a 5 amp fuse and one battery. Bought a second to camp more that 2 -3 nights. Later added an inverter that also had USB chargers that required the separate 12 awg cable to support it. Added the solar panel last year to support a week long camping trip to Assateague Island. Converted to Anderson pole connectors with the addition of the solar panel and also added the NOCO cigarette lighter adapter at the same time. Sounds like you don't require this level of complexity for your needs.

Hi Lane,

Sorry to resurrect on old post here. I've built my 35Ah battery for my wife's CPAP and its working well in testing, now I am looking to build a smaller 20Ah battery to be able to recharge electronics and blow up our air mattresses. This is what I am looking at and was wondering of your input.

Battery: https://www.amazon.com/ExpertPower-EXP1 ... way&sr=8-1
Connector: https://www.amazon.com/NOCO-GC018-Adapt ... ive&sr=1-1 Should I look to use a smaller fuse than the 15A that it comes with?
Inverter: https://www.amazon.com/Ampeak-400W-Powe ... way&sr=8-3 to be able to connect various electronics for charging.

Could it really be that simple, or am I missing something? I would of course get a box to be able to contain the battery.

Hi Bbergin76,

The three components you list are exactly the items currently in our modular system and with the caveats below they have all worked well since they were acquired as upgrades/replacements for our 2018 Assateague Island trip mentioned earlier. Comments as follows:

1) ExpertPower 12200 20ah battery: Bought our first one last year right before our Assateague trip and it has worked well. Arrived fully charged reading 13.1 volts with no load and, based on usage, appears to deliver stated amp hour capacity. Second replacement battery delivered this year arrived in similar condition and did well in an initial load test. Based on experience and generally good reviews would recommend the battery. Also at $40 on Amazon it's priced well. One year after purchase the first battery is still doing well. Note that in the off-season we top off the charge every couple of months and additionally cycle the batteries (use only 20% of capacity) if not used for 4 months to prevent sulfation. We have 5 other lower capacity (7 and 8 amp hour) ExpertPower batteries as replacements for our PC UPS and Verizon Fios backup that have also worked well - so far for up to 2 and a half years. Good ratings on Amazon also support this.

2) NOCO GC018: This has worked will for us as noted earlier. Note that the 15 amp fuse that comes with it is too high for 16 awg wire and needs to be replaced with a lower capacity fuse. See the June 16th review by sandygee for this item (full disclosure that the review is mine and this is our family account under my wife's online name). When we stripped the wires to attach the Anderson connectors we discovered something other than 100% copper wire (see review pictures). Normally a 10 amp fuse would be fine for 16awg wire, we used a 7.5 amp fuse in case this is aluminum. We currently use this adapter to inflate our air mattresses (12 volt inflater that does not require an inverter) and charge phones (with a 5 volt cigarette lighter charger) when camping.

3) Ampeak 400watt inverter: Has performed well for us since purchased last year. Overkill with a 20 ah battery but we wanted the extra capacity should we want to use in on our auto in an emergency. You really don't want to draw more than 5 amps (60 watts) from a 20 ah (battery will last about 3 hours before dropping below 11 volts when new). At 12 amps (144 watts) the battery will only last an hour.

If you plan on staying at or below 5 amps you may be able to use the cigarette lighter adapter that comes with the Ampeak and the NOCO GC018 with a 7.5 amp fuse. Per CapnLoki keep some spares in case a power spike blows the fuse. With 50% extra fuse capacity there should be minimal nuisance fuse blows. Test it out with your planned power loads to ensure that there isn't an excessive voltage drop or initial voltage spike that blows your NOCO fuse.

We converted to 12 awg wire from our battery to minimize DC voltage drop in addition to providing a 20 amp current capacity for additional safety margin with a 15 amp fuse. When we first build our camping power supplies years back we found that our prior inverter (Harbor Freight) would kick in with a low voltage alarm with smaller 18 gauge wire/barrel connectors that ran my CPAP and could theoretically handle the amps required for the desired inverter use. Have had no issues with the 12 gauge auto zip wire we currently use direct to the inverter.

One additional note, we replaced the two 35 amp fuses that come installed in the Ampeak with 25 amp fuses for better protection in emergency use as we don't expect to use full unit capacity. With our battery pack the 15 amp fuse on wire that connects to the Ampeak will blow long before the inverter fuses ever come into play. See my June 4th, 2018 review for the Ampeak on Amazon under sandygee for additional perspective. Only complaint was that the fan kicks in at lower power usage than expected (60 watt test). Still much better than the older inverter this replaced. Fan did not kick in for our AC current ZZZPap machine, that I use at home, when tested. The externally mounted user replaceable fuses are a big plus for this unit as many inverters at this price point have fuses that are soldered in and not user replaceable.

You have a variety of options to house a battery of this size. We place our half-U1 size 20ah batteries in the bottom half of an inexpensive plastic ammo box or Rubbermaid 3.25"x 9"X 2" vinyl/rubber drawer organizer that in turn is placed in a 12 inch tool bag that is easy to carry. Wanted something hard protecting the battery base and bag has space for a charger and or inverter plus cables. Within the bag all metal connections are covered with heat shrink tubing and/or electrical tape so there is nothing exposed to an accidental short circuit. Just unzip the bag and pull out the battery wire. We use this bag for one of our 20ah batteries:
https://www.amazon.com/Husky-Inch-Contr ... 0778&psc=1
Can often find it at Home Depot for less. The draw organizer in one battery pack is from Target and the ammo box bottom from Harbor Freight (typically $3.99 with coupon). Just remove the top. Other types of soft side bags/small backpack may work. In the case of your 35 ah battery just get a U1 battery box.

Got the idea for a soft side container from the now discontinued Respironics Battery Pack. See the link below at cpap.com that has a picture of the opened pack with a taped lead acid agm battery:
https://www.cpap.com/productpage/respir ... -cable-kit
By the way, the detailed specs on this show a 14.4 amp hour capacity - 80% of an 18 amp hour Half-U1 size battery that was likely used. Validated a lot of my design on these specs including the fuses. This uses a main 15 amp fuse on the battery with either a 3, 5 or 7 amp fuse on the CPAP machine cord based on specific device specifications.


Feel free to reach out with any additional questions.

CapnLoki wrote: ↑

Thu Jun 20, 2019 12:44 pm

campervan wrote: ↑

Thu Jun 20, 2019 10:53 am

- Battery Tender cigarette lighter adapter (I realize this might not be all that helpful but maybe a long car drive would be enough to top us off for another few hours' worth of charge) ($8):
https://www.amazon.com/Battery-Tender-B ... 003CJ927I/

I knew this one was going to come up - it has to be discussed every year or so. The "SAE to Cigarette Plug" adapter is for charging a car's battery with a BatteryTender, NOT for charging an outside battery from a car's charging circuit. Unfortunately its not obvious to tell by looking at it, and with the system we're putting together it sure looks like it would work. However, ITS WIRED BACKWARDS!!! and will instantly pop the fuse (either in the car or in the battery wire).

[/quote]

Hi Campervan,

CapnLoki is absolutely right regarding the SAE to Plug adapter for charging. An additional option would be to purchase a small inverter to run the BatteryTender while you are driving. I own the Costco 3 amp Battery Tender and it's rated input current is 0.8 amps at 120 volts or 96 watts. A small 150 to 200 watt inverter would likely be able to handle that. You should also confirm that your car circuit is spec'd to provide what will likely be 10 amps of 12 volt DC current based on typical inverter efficiencies. This should not be used when your vehicle is not running as the battery could quickly be depleted.

Lane101 wrote: ↑

Sat Jul 13, 2019 7:28 pm

Hi Bbergin76,

The three components you list are exactly the items currently in our modular system and with the caveats below they have all worked well since they were acquired as upgrades/replacements for our 2018 Assateague Island trip mentioned earlier. Comments as follows:

1) ExpertPower 12200 20ah battery: Bought our first one last year right before our Assateague trip and it has worked well. Arrived fully charged reading 13.1 volts with no load and, based on usage, appears to deliver stated amp hour capacity. Second replacement battery delivered this year arrived in similar condition and did well in an initial load test. Based on experience and generally good reviews would recommend the battery. Also at $40 on Amazon it's priced well. One year after purchase the first battery is still doing well. Note that in the off-season we top off the charge every couple of months and additionally cycle the batteries (use only 20% of capacity) if not used for 4 months to prevent sulfation. We have 5 other lower capacity (7 and 8 amp hour) ExpertPower batteries as replacements for our PC UPS and Verizon Fios backup that have also worked well - so far for up to 2 and a half years. Good ratings on Amazon also support this.

2) NOCO GC018: This has worked will for us as noted earlier. Note that the 15 amp fuse that comes with it is too high for 16 awg wire and needs to be replaced with a lower capacity fuse. See the June 16th review by sandygee for this item (full disclosure that the review is mine and this is our family account under my wife's online name). When we stripped the wires to attach the Anderson connectors we discovered something other than 100% copper wire (see review pictures). Normally a 10 amp fuse would be fine for 16awg wire, we used a 7.5 amp fuse in case this is aluminum. We currently use this adapter to inflate our air mattresses (12 volt inflater that does not require an inverter) and charge phones (with a 5 volt cigarette lighter charger) when camping.

3) Ampeak 400watt inverter: Has performed well for us since purchased last year. Overkill with a 20 ah battery but we wanted the extra capacity should we want to use in on our auto in an emergency. You really don't want to draw more than 5 amps (60 watts) from a 20 ah (battery will last about 3 hours before dropping below 11 volts when new). At 12 amps (144 watts) the battery will only last an hour.

If you plan on staying at or below 5 amps you may be able to use the cigarette lighter adapter that comes with the Ampeak and the NOCO GC018 with a 7.5 amp fuse. Per CapnLoki keep some spares in case a power spike blows the fuse. With 50% extra fuse capacity there should be minimal nuisance fuse blows. Test it out with your planned power loads to ensure that there isn't an excessive voltage drop or initial voltage spike that blows your NOCO fuse.

We converted to 12 awg wire from our battery to minimize DC voltage drop in addition to providing a 20 amp current capacity for additional safety margin with a 15 amp fuse. When we first build our camping power supplies years back we found that our prior inverter (Harbor Freight) would kick in with a low voltage alarm with smaller 18 gauge wire/barrel connectors that ran my CPAP and could theoretically handle the amps required for the desired inverter use. Have had no issues with the 12 gauge auto zip wire we currently use direct to the inverter.

One additional note, we replaced the two 35 amp fuses that come installed in the Ampeak with 25 amp fuses for better protection in emergency use as we don't expect to use full unit capacity. With our battery pack the 15 amp fuse on wire that connects to the Ampeak will blow long before the inverter fuses ever come into play. See my June 4th, 2018 review for the Ampeak on Amazon under sandygee for additional perspective. Only complaint was that the fan kicks in at lower power usage than expected (60 watt test). Still much better than the older inverter this replaced. Fan did not kick in for our AC current ZZZPap machine, that I use at home, when tested. The externally mounted user replaceable fuses are a big plus for this unit as many inverters at this price point have fuses that are soldered in and not user replaceable.

You have a variety of options to house a battery of this size. We place our half-U1 size 20ah batteries in the bottom half of an inexpensive plastic ammo box or Rubbermaid 3.25"x 9"X 2" vinyl/rubber drawer organizer that in turn is placed in a 12 inch tool bag that is easy to carry. Wanted something hard protecting the battery base and bag has space for a charger and or inverter plus cables. Within the bag all metal connections are covered with heat shrink tubing and/or electrical tape so there is nothing exposed to an accidental short circuit. Just unzip the bag and pull out the battery wire. We use this bag for one of our 20ah batteries:
https://www.amazon.com/Husky-Inch-Contr ... 0778&psc=1
Can often find it at Home Depot for less. The draw organizer in one battery pack is from Target and the ammo box bottom from Harbor Freight (typically $3.99 with coupon). Just remove the top. Other types of soft side bags/small backpack may work. In the case of your 35 ah battery just get a U1 battery box.

Got the idea for a soft side container from the now discontinued Respironics Battery Pack. See the link below at cpap.com that has a picture of the opened pack with a taped lead acid agm battery:
https://www.cpap.com/productpage/respir ... -cable-kit
By the way, the detailed specs on this show a 14.4 amp hour capacity - 80% of an 18 amp hour Half-U1 size battery that was likely used. Validated a lot of my design on these specs including the fuses. This uses a main 15 amp fuse on the battery with either a 3, 5 or 7 amp fuse on the CPAP machine cord based on specific device specifications.


Feel free to reach out with any additional questions.

Been doing some testing with the 35AH battery using the CPAP and so far we have gotten 4 nights out of it. I have no method to measure remaining charge as of yet, but we can b e comfortable that we will get at least 4 nights out of it.

Ordered pieces for a smaller 20AH battery to charge other electronics like cellphones, bluetooth speaker and possibly the boys DS, as well as use of our air mattress pump. With using the ring connector/cigarette lighter connection that comes with the AMPEAK, the inverter goes in to an error state with the audible alarm so it is drawing too much power using the cigarette lighter connection. My options are to use the alligator clips, which isn't that attractive since I don't particularly want to keep alligator clips connected to the battery plus they don't seem to fit very well with the terminals on the ExpertPower 12200 battery to keep them connected for an extended period of time. Not keeping them connected then means I would have to open the box while camping to switch connections from the alligator clip to blow up the air mattresses to the cigarette lighter connection to charge the rest of our devices that are low draw. I supposed I could always run the air pump through our van 115V outlet, since in theory I shouldn't be running it too long.

For the lower draw devices, if I use the inverter, am I lower the capacity of my battery? I am better off charging through the cigarette lighter connector whenver I can aren't I? I do have a USB adapter that I can use with the cigarette lighter adapter to charge the phones and probably the Bluetooth Speaker but I am forced in to using the inverter for the DS.

For the case I did find a smaller case that the 20AH fits inside, although there is a lot of room still left over. Might not be too bad though as it looks like the AMPEAK will fit in that empty space for storage/transport when not in use.

Hi Bbergin76,

35ah Battery State of Charge: If you have a multi meter you can test the voltage of your 35ah battery to get a sense of its state-of-charge. While exact figures will vary by manufacturer and battery age a new agm should be above 13 volts when fully charged (At rest overnight after charging with no load). My ExpertPower 20ah batteries came in at about 13.1 volts at full charge when new. The year old battery now comes in at just under 13 volts (12.98 when measured). A 9 year old Power Sonic 18ah battery I just replaced topped off at 12.5 volts after charging and per a load test was down to roughly half it's rated capacity. One chart on the web shows a resting AGM battery at 13.00 volts at 100% charge, 12.05 volts when at a 50% and 11.66 volts at 20%. Again battery specs are manufacturer specific so take these as approximate.

Ampeak Inverter Usage: Using the inverter is always less efficient than running directly on 12 volts. The maximum efficiency for our Ampeak inverters (per specs in instruction booklet) is 85%. Assuming 80% efficiency a 60 watt power requirement, 5 amps at 12 volts, will draw 6.25 amps from the battery. If a device, such as your mattress inflator, can work directly on 12 volts don't use a power adapter on the inverter. For your low draw items the answer will depend on the efficiency of your USB charger compared to the Ampeak (assume you are using the 5V USB socket on the Ampeak). Unless you have the specs on your USB charger from samples I've seen published on the web the efficiency could be similar so use whatever is most convenient. We use a USB charger in the NOCO because it's just easier to set up.

Regarding the low voltage alert (when you use the cigarette lighter adapter to connect the Ampeak to the battery), I'd need to understand more on the load you are running with the Ampeak, confirm how you are connecting the adapter to the battery (including the total length of all wiring between the battery and inverter, and that the battery was fully charged. Just looked at my Ampeak adapter and the wires are spec'd at a 1.28 square MM area that equates to just under a 16 gauge wire. While the adapter has a 15 amp glass fuse the instructions, on the adapter wire, state not to run at 120 watts or above. That equates to roughly 10 amps (at 12 volts) and a device load of under 7-8 amps given inverter efficiency. This also assumes we really have close to 16 awg wire. Have seen some imported devices where the wire is thinner than spec'd. Recommend as a first step that you test your devices with the alligator clip connectors. If you still get an alarm you likely have either a battery or inverter flaw that may necessitate a return if the load is within specs. If you have a multi meter that can measure the DC voltage, coming to the Ampeak when under load, that will help diagnose the issue. If the inverter works with the alligator clip connectors then the likely issue is that the cigarette lighter adapter is causing too much voltage drop with the current required so you will need to make or buy a connector with heavier gauge wire as the alligator clips are not preferred and are risky. Also they can not be left on the battery - too much risk of a short circuit and shock hazard and the OEM alligator cables with the Ampeak are not fused so a significant fire hazard too. CapnLoki summarized these well as "an accident waiting to happen".

From my last post I experienced similar voltage loss problems with my first inverter using 18 awg wire and solved the issue via the use of 12 awg auto zip wire (15 amp fuse on positive wire) with Anderson connectors on both batteries that I then connect to my device or NOCO socket wires where I've also installed Anderson connectors. For the inverter I built a second 12 awg zip wire cable with Anderson connectors for the battery wire just mentioned and O-rings for the inverter. This works well for our needs that don't exceed roughly 60 watts (5 amps) and is spec'd to handle up to 180 watts. Also kept thr total length of both wires to under 4 feet to further minimize voltage loss. I tested this with a 160 watt load (13.3 amps though likely over 16 amps due to inverter efficiency) and it ran without a low voltage warning for two minutes on a fully charged battery. Run my battery load tests with the Ampeak at 60 watts for as much as an hour with no inverter issues. The wire gauge specifically required will depend on the current you need to pull from the battery.

Recommend nothing above a 12 awg if you buy something since the current 16 awg is causing problems. May need a heavier (lower) awg if your loads are more than above.

Let us know how this works out.

Can you not also get a DS usb charge cable the inverter is a poor use of your power

Lane101 wrote: ↑

Mon Jul 15, 2019 3:37 pm

Hi Bbergin76,

Ampeak Inverter Usage: Using the inverter is always less efficient than running directly on 12 volts. The maximum efficiency for our Ampeak inverters (per specs in instruction booklet) is 85%. Assuming 80% efficiency a 60 watt power requirement, 5 amps at 12 volts, will draw 6.25 amps from the battery. If a device, such as your mattress inflator, can work directly on 12 volts don't use a power adapter on the inverter. For your low draw items the answer will depend on the efficiency of your USB charger compared to the Ampeak (assume you are using the 5V USB socket on the Ampeak). Unless you have the specs on your USB charger from samples I've seen published on the web the efficiency could be similar so use whatever is most convenient. We use a USB charger in the NOCO because it's just easier to set up.

Regarding the low voltage alert (when you use the cigarette lighter adapter to connect the Ampeak to the battery), I'd need to understand more on the load you are running with the Ampeak, confirm how you are connecting the adapter to the battery (including the total length of all wiring between the battery and inverter, and that the battery was fully charged. Just looked at my Ampeak adapter and the wires are spec'd at a 1.28 square MM area that equates to just under a 16 gauge wire. While the adapter has a 15 amp glass fuse the instructions, on the adapter wire, state not to run at 120 watts or above. That equates to roughly 10 amps (at 12 volts) and a device load of under 7-8 amps given inverter efficiency. This also assumes we really have close to 16 awg wire. Have seen some imported devices where the wire is thinner than spec'd. Recommend as a first step that you test your devices with the alligator clip connectors. If you still get an alarm you likely have either a battery or inverter flaw that may necessitate a return if the load is within specs. If you have a multi meter that can measure the DC voltage, coming to the Ampeak when under load, that will help diagnose the issue. If the inverter works with the alligator clip connectors then the likely issue is that the cigarette lighter adapter is causing too much voltage drop with the current required so you will need to make or buy a connector with heavier gauge wire as the alligator clips are not preferred and are risky. Also they can not be left on the battery - too much risk of a short circuit and shock hazard and the OEM alligator cables with the Ampeak are not fused so a significant fire hazard too. CapnLoki summarized these well as "an accident waiting to happen".

From my last post I experienced similar voltage loss problems with my first inverter using 18 awg wire and solved the issue via the use of 12 awg auto zip wire (15 amp fuse on positive wire) with Anderson connectors on both batteries that I then connect to my device or NOCO socket wires where I've also installed Anderson connectors. For the inverter I built a second 12 awg zip wire cable with Anderson connectors for the battery wire just mentioned and O-rings for the inverter. This works well for our needs that don't exceed roughly 60 watts (5 amps) and is spec'd to handle up to 180 watts. Also kept thr total length of both wires to under 4 feet to further minimize voltage loss. I tested this with a 160 watt load (13.3 amps though likely over 16 amps due to inverter efficiency) and it ran without a low voltage warning for two minutes on a fully charged battery. Run my battery load tests with the Ampeak at 60 watts for as much as an hour with no inverter issues. The wire gauge specifically required will depend on the current you need to pull from the battery.

Recommend nothing above a 12 awg if you buy something since the current 16 awg is causing problems. May need a heavier (lower) awg if your loads are more than above.

Let us know how this works out.

Hi Lane,

My mattress inflator does not have a 12 volt power adapter, only a AC adaptor. The alert comes on when I have the AC adaptor connected to the AMPEAK which has the cigarette lighter adapter connected to this https://www.amazon.com/gp/product/B0041 ... UTF8&psc=1 and then that is connected to the battery with https://www.amazon.com/gp/product/B000N ... UTF8&psc=1. I did it this way instead of NOCO in case I wanted to add a 5-1 splitter to charge more than one thing at a time if I opted for the USB adapters for the cellphones and bluetooth speaker.

When I use the alligator clip from the AMPEAK I do not get the alert. The paperwork I have for the inflator only says 110-120V and 0.6A. I have been unsuccessful in finding more information online.

Looks like I may only need the AMPEAK for the mattress inflator. If I purchase a USB charger for the DS, as suggested by Jas_williams then I can actually run everything through a USB adapter connected to the battery through a cigarette lighter adaptor except for the inflator of course.

I didn't think of this until you mentioned it but I could look to buy a mattress pump with a 12V connection and return the AMPEAK.

You could buy a self powered pump, if you aren't too disabled, or even a tank that can be filled with air from a air compressor. Jim

bbergin76 wrote: ↑

Tue Jul 16, 2019 10:38 am

Lane101 wrote: ↑

Mon Jul 15, 2019 3:37 pm

Hi Bbergin76,

Hi Lane,

My mattress inflator does not have a 12 volt power adapter, only a AC adaptor. The alert comes on when I have the AC adaptor connected to the AMPEAK which has the cigarette lighter adapter connected to this https://www.amazon.com/gp/product/B0041 ... UTF8&psc=1 and then that is connected to the battery with https://www.amazon.com/gp/product/B000N ... UTF8&psc=1. I did it this way instead of NOCO in case I wanted to add a 5-1 splitter to charge more than one thing at a time if I opted for the USB adapters for the cellphones and bluetooth speaker.

When I use the alligator clip from the AMPEAK I do not get the alert. The paperwork I have for the inflator only says 110-120V and 0.6A. I have been unsuccessful in finding more information online.

Looks like I may only need the AMPEAK for the mattress inflator. If I purchase a USB charger for the DS, as suggested by Jas_williams then I can actually run everything through a USB adapter connected to the battery through a cigarette lighter adaptor except for the inflator of course.

I didn't think of this until you mentioned it but I could look to buy a mattress pump with a 12V connection and return the AMPEAK.

Hi Bbergin76,

Since the inflator runs well, with the heavier alligator clip cables, you are running into the same issue I had years earlier (see my last post) where even though the wires can handle the current the voltage drop is too high. As a result a heavier gauge wire is required. Battery and Ampeak are likely fine. The mattress inflator is pushing the limits of the two Battery Tender connectors as follows:

1) At a max of 0.6 amps and 120 volts the inflator requires up to 72 watts likely growing to 90 watts at 12 volts into the inverter given its efficiency. That equates to 7.5 amps of 12 volt current going through connectors with a combined length of 9.5 feet (Two Battery Tender Connectors and Ampeak cigarette plug cable). This is likely beyond the ideal maximum for the Battery Tender cables that are fused at 7.5 amps as fusing is typically set with a margin above expected current to avoid nuisance blown fuses.

2) Some rough calculations further validate the likelihood of a low voltage issue. The wires are either 16 or 18 awg (per Amazon Q&A both were claimed in separate answers, not marked on my connector - 18 awg possible as 16 could be fused at 10 amps) resulting in a roughly 5.3% to 8.5% voltage drop (per an on-line voltage loss calculator, link below). Under load your battery voltage will drop (my Exp12200 dropped from 13.0 volts at no load to 12.3 immediately under a 60 watt load test through my Ampeak). Adjusting further for the voltage loss and you could be down to just under 11.3 volts which is within the Ampeak low voltage alert range of 11.0 +/-0.3. A less then fully charged battery will result in even lower voltage levels. A heavier 12 gauge wire connector at a shorter four foot length would see a voltage drop of under 1%. Bottom line is that if you decide to use the Ampeak you need to use a heavier gauge fused connection to the battery. Shorter wires also help.

We use an Intex inflator that has an AC adaptor as well as a car cigarette lighter 12 volt plug. We just plug the latter into our NOCO and power it directly off our 20ah batteries. If your inflator AC adaptor is not permanently connected see if it actually converts to 12 volt DC and you can use your NOCO if you have the right cigarette lighter plug. Additional benefit of eliminating current lost due to adaptor efficiency.

I'm not familiar with the DS specs so you will need to determine if that will work. Great suggestion from Jas if it supports a USB charger that meets your needs. Per my earlier post we use a USB car charger in the NOCO for all of our 5 volt power needs as its easier than running the Ampeak. Efficiency versus the Ampeak will depend on your USB charger specs.

Voltage drop calculator link for reference:

https://www.calculator.net/voltage-drop ... &x=54&y=18

Wow, just read all 13 pages of this topic. I am very experienced with low voltage systems like those on boats. Most of what I have read here is related to camping. I want a system for short power outages (minutes to a few hours) that is automatic when the outage happens. If there was a long outage I have all the batteries and adapters that I would need and ways to charge. So I am looking at UPS systems and Lithium power packs. I understand that UPS system is specifically designed for this use but the batteries are maybe too small. I have looked at a few lithium power packs but it is not clear to me how they would work in this situation. Can I plug my CPAP machine (no humidifier) into the 12v outlet of the power pack and plug the pack into 110 in a semi-permanant set up? In that mode are you running off AC or running off battery power that will recharge during the day? I am just thinking of long term repeated charge discharge cycles.

ak-guy wrote: ↑

Thu Jul 18, 2019 12:25 pm

Wow, just read all 13 pages of this topic. I am very experienced with low voltage systems like those on boats. Most of what I have read here is related to camping. I want a system for short power outages (minutes to a few hours) that is automatic when the outage happens. If there was a long outage I have all the batteries and adapters that I would need and ways to charge. So I am looking at UPS systems and Lithium power packs. I understand that UPS system is specifically designed for this use but the batteries are maybe too small. I have looked at a few lithium power packs but it is not clear to me how they would work in this situation. Can I plug my CPAP machine (no humidifier) into the 12v outlet of the power pack and plug the pack into 110 in a semi-permanant set up? In that mode are you running off AC or running off battery power that will recharge during the day? I am just thinking of long term repeated charge discharge cycles.

I'm impressed - I have trouble reading all this stuff and I wrote half of it! Most of this applies to camping or backup but in fact the knowledge was gained on boats, and I hate camping!

It is quite possible to use my home backup system in UPS Mode - you just use a 1 to 5 splitter so a charger feeds both the battery and the pump. (Actually the battery is on the "1" side and the charger, pump, and any other load is on the "5" side.) I setup in this mode if there's a strong storm expect in the middle of the night. The problem I have with this is that my charger doesn't quite satisfy the pump load so the battery would end up being drained every night and recharged during the day. This would put a lot of wear on the battery and the charger. If I really needed this full time I would get a larger BatteryTender (5 or 6 amps) that could handle the pump load without too much effort.

The same problem applies to a lithium pack - they often have a tiny charger so the batteries would get fully cycled and the charger might not be able to keep up during the day. They are often rated for 500 cycles, so this might mean a year and a half lifetime!

A simple UPS with a 7 amp-hour battery might only cover several hours if the humidifier is on high, but its designed to sit on standby for 5-10 years and then you replace the battery for $40. If your need is really the occasional 1 hour outage this is the best solution. That, plus a hefty U1 cell for longer outages is still cheaper than a lithium pack.

ak-guy wrote: ↑

Thu Jul 18, 2019 12:25 pm

A simple UPS with a 7 amp-hour battery might only cover several hours if the humidifier is on high, but its designed to sit on standby for 5-10 years and then you replace the battery for $40. If your need is really the occasional 1 hour outage this is the best solution. That, plus a hefty U1 cell for longer outages is still cheaper than a lithium pack.

Hi Ak-guy, If all you want is a few hours of automatic back up then UPS is the way to go as noted by CapnLoki. You may want to look at higher capacity UPS such as those from Cyberpower (see link to unit on Amazon below for $135). We own one of these for our home theater and it has held up well. I has two 8 amp hour 12v agm batteries that some, per comments and reviews, have used successfully for a few hours of CPAP backup. If you don't use a humidifier you may be able to get an entire evening from this depending on how efficiently it converts DC to AC power. Note that you need to confirm that your CPAP machine is within the power specs and can handle the simulated sine wave power produced any UPS. Make sure you periodically load test the batteries. We replaced ours after 4 years when they died. If using for CPAP back up my guess is they would have needed replacement earlier before they lost all capacity.

https://www.amazon.com/CyberPower-CP135 ... B000OFXKFI

As you are familiar with low voltage systems you may substitute higher capacity batteries that would be housed outside the UPS itself. Have seen some examples on-line where this has been done. Note the batteries here are connected in series to generate 24 volts DC for the CyberPower UPS.

The other option is to purchase a CPAP that is designed for a battery backup. Devilbiss Intellipaps have separate AC and DC inputs that allow operation on AC power with a 12 volt DC battery also attached. They automatically switch over to DC though the DC does not power the humidified. Respironics Dreamstation has an optional Li-ion battery that does the same though this is a very pricey option.

Finally this thread on CPAPtalk, though a few years old, may also help:

viewtopic/t5608/Uninterruptible-Power-S ... tml#p50463

CapnLoki wrote: ↑

Sun Oct 16, 2016 10:07 am

If you're looking to save money, you can get a WalMart flooded maintenance free marine battery starting at about $75 but they'll ask for an old battery in trade (core exchange). Make sure they say "Deep Cycle" as the "Marine Starting" versions look almost the same. The power is 80 to 110 AH, proportional to the weight. This might be the best solution for some folks, but I have trouble recommending them for any application that implies having them next to a bed, or carrying them around, or even sitting in a trunk.

Enough for now. I'll more info on other topics such as lithium options and solar charging later.

What is your take on these small self-contained battery back-up power generators for use with CPAP's?

TheBigTenor wrote: ↑

Sat Jul 27, 2019 8:50 am

What is your take on these small self-contained battery back-up power generators for use with CPAP's?

I was preparing long list of sarcastic remarks based on the term "power generator" when in fact it generates nothing, but on close inspection it seems to have reasonable value for the money. 155 Watt-hours for $140, DC outlets, AC inverter. Your AirSense will need a 12/24V converter from ResMed, and it will use almost 100 Watt-hours at pressure 10 so this will be good for one night without humidity or heated hose. You might get pushback from the airlines which often have a 100 WH limit. For a one night camping trip this looks fine, especially if you value light weight. Don't assume you can recharge it for the next night by running the car for 20 minutes - it looks like it would be 4-7 hours to put back enough for another night.

CapnLoki wrote: ↑

Sat Jul 27, 2019 9:43 am

TheBigTenor wrote: ↑

Sat Jul 27, 2019 8:50 am

What is your take on these small self-contained battery back-up power generators for use with CPAP's?

I was preparing long list of sarcastic remarks based on the term "power generator" when in fact it generates nothing,

I was doing the same, but decided it wasn't worth the time, if stupid people want to believe ads, so be it I looked at the pics, couldn't find a Gas cap or starter rope, it must be oiless, count see the fill cap or dipstick. Personally I would not buy a product that they couldn't name properly. Jim

I consider Ads that misrepresent the product to be a RED FLAG, No Bull!