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Re: Battery Backup Design
Posted: Sun Aug 26, 2012 9:07 am
by JohnBFisher
Well, I got to test my system rather unexpectedly. A transformer in the neighborhood blew itself apart last night. A little fumbling around with a flashlight and I was good to go.
I love it, when a plan comes together and works!!
Re: Battery Backup Design
Posted: Sat Oct 27, 2012 5:34 am
by deltadave
During a review of the sudden (and perhaps justified) interest in battery info, it is noted that the above link appears broken.
This looks like a (the) later version:
http://www.resmed.com/us/assets/documen ... lo_eng.pdf
Re: Battery Backup Design
Posted: Sat Oct 27, 2012 5:18 pm
by ChrisD
John,
Just wanted to jump in and say thank you for posting this thread and thanks to all who have contributed to it. Very informative. Did you ever create the Wiki page like you mentioned?
Using the info from this thread and others here on this forum, I felt comforable building one of my own:
1) MinnKota Trolling battery box w/ 2 12v accessory plugs. PN# 1820175 Wal-Mart cost: $52.00
2) Schumacher 1.5 Amp Automatic battery Maintainer/Charger PN#SE-1-12S Walmart cost: $44.00
3) Phillips Respironics 12 Volt DC Power Cord Item #1001956 CPAP.com price: $25.00
4) Kirkland (Costco) brand marine deepcycle 115 Amp hour battery PN# 12852 Costco price $89.00
So for $210, I should have a somewhat portable battery solution that I assume will last over a week of 8 hour nights.
I'm hoping Sandy takes out the power for a night or two so I can test it out.
Chris
FYI - Kirkland (Costco) brand has two deepcycle batteries:
1) PN# 12851, 85 Amp Hours, 30 month warranty, $73.00
2) PN# 12852, 115 Amp Hours, 30 month warranty, $83.00
Re: Battery Backup Design
Posted: Sat Nov 03, 2012 12:55 pm
by JohnBFisher
I copy the following from another post. It's excellent information. Use in good health !!
Burkebang wrote:I run a cleaning company and we have a few floor scrubbers, like this:
So as you can understand I have some experience in caring for deep cycle batteries. In my experience, deep cycle batteries needs to be used in order to survive and maintain their capasity over time. Believe me, this experience has cost me a few thousand "burkes" to get
What we do with our idle machines is to run the batterys half way down and recharge them at least once every three months. We also don't have battery chargers/tenders running on them constantly, this does reduce the lifetime and the batterys ability to hold charge over time. While start batterys are perfectly happy with battery tenders for years, deep cycle batterys are not.
If I was to build a battery backup system, I would mainly follow JohnBFishers excellent suggestions, with a few modifications. I would use the best battery charger I know of, the Ctek MXS 5.0. At the end of every month, I'd use the battery to power my CPAP every day for as long as it's needed to get the battery down to at least half charge. Then I'd connect the charger for 24 hours to top off the battery, remove the charger, check the water level and leave the battery disconnected until next month.
http://www.amazon.co.uk/CTEK-CTE-MXS5-0 ... B004ZWV1JI
Well, that's how I'd do it Fortunatly I have very reliable power and have only been without power for one night in the 10 years I have lived in my current house. So I'm very happy having only a jumpstarter with a well tended 19 AH battery as backup and for starting dead cars
Edit:
What happens to the deep cycle batteries left on tender or constant charge is that everything looks fine, they maintain their voltage and there is no indication of any problems with the battery. But when you start running the scrubber, a machine that should run for 6 hours, will suddenly run flat in 10-20 minutes.
Re: Battery Backup Design
Posted: Fri Jan 04, 2013 2:07 am
by cosmo
I've got half of my setup. Just need a battery and battery box. Maybe a new battery charger/tender? Mine is a Schumacher SC-1200A I bought years ago for automobile use. Do I need a new one?
Schumacher SC-1200A link
http://www.amazon.com/gp/product/B000BQSIWK
I can use either and S9 Autoset or IntelliPAP machine.
I was pricing some batteries at Costco yesterday. Looks like the larger $82.99 (group 27) 115ah is the one to get. Might grab 2. Second would be for charging phone, tablet, etc during outage.
Re: Battery Backup Design
Posted: Fri Jan 04, 2013 4:08 am
by archangle
In theory, the SC-1200 will drop back into a "maintain" or "float" mode and not damage the battery even if it's left connected all the time.
In practice, I've seen a lot of chargers that will eventually "eat" the battery if left hooked up for several months, even if they claim to have a "float" mode and be OK to be hooked up full time.
This charger also does a "desulfation" mode. While that's good for the battery, it may not be good for your CPAP machine. I would NOT leave this hooked up to the battery at the same time the CPAP machine is hooked up to the battery. Note that unplugging the charger from the wall may not be enough. You may need to unhook it from the battery. I have a different model charger that will desulfate even if unplugged. The desulfation circuit runs off the 12V from the battery even if unplugged from the wall.
Re: Battery Backup Design
Posted: Fri Jan 04, 2013 4:28 am
by lilly747
JohnBFisher wrote, What happens to the deep cycle batteries left on tender or constant charge is that everything looks fine, they maintain their voltage and there is no indication of any problems with the battery. But when you start running the scrubber, a machine that should run for 6 hours, will suddenly run flat in 10-20 minutes.
I was given two brand new 29H batteries. I was told they are bigger than a regular marine battery. They have more plates for one thing. I know nothing about batteries. I guess what John wrote applies to these batteries too???? and does anyone know anything about the 29H battery??
Re: Battery Backup Design
Posted: Fri Jan 04, 2013 11:11 am
by cosmo
archangle wrote:
In practice, I've seen a lot of chargers that will eventually "eat" the battery if left hooked up for several months, even if they claim to have a "float" mode and be OK to be hooked up full time.
I don't plan on having the batteries on float mode. Just use it for a few nights each month and then recharging.
From what the internet says, these batteries are not true deep cycle but hybrids that should not drop below 50% discharge. But I don't really care if I lose a battery. If I'm using battery power for 10+ days at home, losing a $90 battery would be the least of my worries
Re: Battery Backup Design
Posted: Fri Jan 04, 2013 4:31 pm
by archangle
lilly747 wrote:JohnBFisher wrote, What happens to the deep cycle batteries left on tender or constant charge is that everything looks fine, they maintain their voltage and there is no indication of any problems with the battery. But when you start running the scrubber, a machine that should run for 6 hours, will suddenly run flat in 10-20 minutes.
I was given two brand new 29H batteries. I was told they are bigger than a regular marine battery. They have more plates for one thing. I know nothing about batteries. I guess what John wrote applies to these batteries too???? and does anyone know anything about the 29H battery??
"29H" refers to the size of the case, and doesn't tell you much about what kind of battery they are. Here's a "group size" chart.
http://www.rtpnet.org/teaa/bcigroup.html 29H is sort of on the big end, but you'd still think of it as "car battery" size.
With the right charger, the battery will work just fine after being charged 24/7 for years. I have a 100 Ah marine deep cycle batteries that's been on a trickle charger for years. I recently hooked up a 5 amp load to test it and got 50 amp hours out of it, and the voltage hadn't dropped significantly. I did not try to run it down all the way to find out the capacity. I just ran it long enough to decide it's OK and recharged it.
I charge it with a Schumacher SE-1-12s charger. I've found over the years that this model seems to work with no battery damage. Some other chargers I've tried have damaged the battery over time despite claiming to be good for 24/7 charging.
Even with the right charger, the battery does eventually go bad. I probably average around 5 years.
It is important to check batteries every so often. I have some "smarter" ways to check them, but the best way is to put a known load on the battery, run it for a while, and then check the battery. I have a 12V 60W incandescent "trouble light" with battery clips that I use as a 5 amp load. Run it for 20 hours, check the voltage, and I know I've gotten about 50 Ah out of the battery. Don't do it TOO often, and don't run it down too far.
BTW, write the purchase date on the battery if it's not there already. You'll be amazed how quickly your 5 years are up.
Re: Battery Backup Design
Posted: Fri Jan 04, 2013 4:42 pm
by cosmo
http://www.harborfreight.com/100-amp-6- ... 90636.html
100 Amp 6 Volt/12 Volt Battery Load Tester $22.99
Load test capacity: 100 amps, 500 to 1000 cold-cranking amps
Battery capacity: 6 volt, 12 volt
Includes heavy-duty battery clips, carrying handle, and rubber feet
Anyone think that is a good idea to use a battery load tester? I always thought about buying one for car usage.
Would this even work for our CPAP/deep cycle setups.
Re: Battery Backup Design
Posted: Fri Jan 04, 2013 4:58 pm
by archangle
I have that exact model. It works just fine for that kind of tester. I'm always skeptical about Harbor Freight stuff, but the one I have has had no problems.
One warning with that kind of tester is that you need to understand how to interpret the results. You don't just hook it up and read the voltage. You have to push the switch, hold for 10 seconds, and understand how to interpret the results.
Some levels that are "bad" for a car battery will be "good" for a deep cycle battery. A deep cycle battery simply doesn't put out as many amps as a starter battery.
It's very useful once you learn how to use it, but not as good as a long term discharge test or one of the smarter automatic battery testers that run a longer test.
Gotta run now. I can give you more info on how to use that tester later if you want.
Re: Battery Backup Design
Posted: Fri Jan 04, 2013 5:22 pm
by cosmo
A primer on battery load testing would be nice. I'm sure a lot of people would find it informative.
I didn't know anything about deep cycle batteries until I joined this forum. Now I'm checking the shelves for marine batteries with the most recent mfg date and the highest AH for the value
Re: Battery Backup Design
Posted: Thu Jan 17, 2013 1:16 am
by cosmo
I have my home backup battery setup in place. What do you guys think?
I am thinking about utilizing the battery every 3rd week to maintain the battery and not leave it on float mode everyday. It will be unplugged and rolled into a spare room.
Typical settings:
Re: Battery Backup Design
Posted: Thu Jan 17, 2013 4:49 am
by archangle
cosmo wrote:
I have my home backup battery setup in place. What do you guys think?
I am thinking about utilizing the battery every 3rd week to maintain the battery and not leave it on float mode everyday. It will be unplugged and rolled into a spare room.
The SC-1200 has a desulfation mode, so don't leave it connected to the battery while the battery is connected to the CPAP, NOT EVEN when the charger is unplugged from AC power.
I have done a similar "limited charge time" thing by plugging my charger into a weekly timer such that it comes on one day a week. There are fairly cheap mechanical weekly timers you plug into an outlet.
Re: Battery Backup Design
Posted: Thu Jan 17, 2013 5:00 am
by archangle
BTW, a close friend did recently have a car battery explode inside his car when he tried to start it on a cold night. I suspect poor maintenance was involved, but still.