Testing DC-12 Converter with 12A battery this weekend

I am going to test the DC-12 Converter with 12A battery this weekend.

Anything that I should be aware of?

I am going to look at the smartcard data afterwards. I wil be looking for anything that may suggest a break in therapy. Also, I am interested in battery output. I will be exploring whether or not it will provide enough power for a night's thearapy.

Good luck and hope it works for you. I would like to have the ability to use my CPAP when the power is out in my area. Just last year my power was out for several days after a storm. Let us know your results and what you used and what you spent to set it all up.

Thanks

Resmed's aren't the most non-standard power machines out there, and battery life would be higher using the 12 volt D/C cord. Jim

Goofproof wrote:Resmed's aren't the most non-standard power machines out there, and battery life would be higher using the 12 volt D/C cord. Jim

Are you saying that Resmed's are the most standard power machines out there?

The thought of using the DC-12 converter is that one, it will keep the power to the machine stable. Also, it has a safe guard regarding draining the battery beyond 40% (?) Since I am not using a deep cycle battery (I am using a motorcycle 12 Amp battery), I thought this may extend the battery's life beyond just a couple of charges. I am going to check the voltage prior to the test and then after the test.

Because I am using an APAP and the pressure have been going as high as 15, I am interested as to whether the battery will be able to power it all night. That is another reason why I am waiting to try it on the weekend, rather than during the week. I had considered an inverter/battery combo, but the inverter uses (wastes) even more energy than the converter. I am also concerned about using only a 12 volt D/C cord as I don't want to void any warranty. Also there seems to be a concensus that the polarity is reversed on Resmed machines. I really don't want to experiment.

If this is what you are going to use it will be fine. https://www.cpap.com/productpage/DC-12-Inverter.html It may come out short of electric.

http://www.resmed.com/en-us/products/se ... teries.pdf Jim



sam1234 wrote:The thought of using the DC-12 converter is that one, it will keep the power to the machine stable. Also, it has a safe guard regarding draining the battery beyond 40% (?) Since I am not using a deep cycle battery (I am using a motorcycle 12 Amp battery), I thought this may extend the battery's life beyond just a couple of charges. I am going to check the voltage prior to the test and then after the test.

Even a 40% discharge on a standard automotive battery is a deeper discharge than it is designed for. Having said that, I'm not clued up on motorbike batteries, they might be specced differently to car batteries, but I doubt it'll be that much different.

sam1234 wrote:Also there seems to be a concensus that the polarity is reversed on Resmed machines.

It is, but if you know that, you just wire the cable that way. My DC connector is a piece of wire with crocodile clips for the battery with a connector soldered onto the other end. There is of course no way for Resmed to check how you powered your CPAP if you ever need to claim, although damage done by sticking the power on in the wrong polarity might well be easy to spot.

sam1234 wrote:I really don't want to experiment.

Chicken

ColinP wrote:

sam1234 wrote:The thought of using the DC-12 converter is that one, it will keep the power to the machine stable. Also, it has a safe guard regarding draining the battery beyond 40% (?) Since I am not using a deep cycle battery (I am using a motorcycle 12 Amp battery), I thought this may extend the battery's life beyond just a couple of charges. I am going to check the voltage prior to the test and then after the test.

Even a 40% discharge on a standard automotive battery is a deeper discharge than it is designed for. Having said that, I'm not clued up on motorbike batteries, they might be specced differently to car batteries, but I doubt it'll be that much different.

sam1234 wrote:Also there seems to be a concensus that the polarity is reversed on Resmed machines.

It is, but if you know that, you just wire the cable that way. My DC connector is a piece of wire with crocodile clips for the battery with a connector soldered onto the other end. There is of course no way for Resmed to check how you powered your CPAP if you ever need to claim, although damage done by sticking the power on in the wrong polarity might well be easy to spot.

sam1234 wrote:I really don't want to experiment.

Chicken

I am chicken. I also expect to be pushing the limits of the battery. I expect to be travelling on a motorcycle for a three nights, one of which will be camping. Anything much bigger, will also weigh more. Plus, this is an extra battery. I will be carrying it on the motorcycle, but it will be used exclusively for the APAP machine. Anyway, I am going to try it tonight!

Well, woke up with the machine still running on battery power. The graph showed my pressure spike at 18. Battery level was at 12.1 volts.

Running time 5.53 hours, Pressure at 14.2 (range set from 10 - 20), leak 0, AHI 3.2, AI .1, HI 3.1.

I hooked the battery up to the charger. It said that the battery had a short. This was not what I expected. The battery has been sitting for over a year, with only one charge recently. I set the charger to recondition the battery. It then was able to hold a charge 12.8V, the same as I started. Whew!

We will see if it holds up to another use on my scheduled ride. I will check its voltage over the next few months. It may or may not. Fortunately, I have to rely on the battery only one night.

sam1234 wrote:Well, woke up with the machine still running on battery power. The graph showed my pressure spike at 18. Battery level was at 12.1 volts.

Running time 5.53 hours, Pressure at 14.2 (range set from 10 - 20), leak 0, AHI 3.2, AI .1, HI 3.1.

I hooked the battery up to the charger. It said that the battery had a short. This was not what I expected. The battery has been sitting for over a year, with only one charge recently. I set the charger to recondition the battery. It then was able to hold a charge 12.8V, the same as I started. Whew!

We will see if it holds up to another use on my scheduled ride. I will check its voltage over the next few months. It may or may not. Fortunately, I have to rely on the battery only one night.

Odd's are the battery was so discharged that the charger was overwhelmed and showed a short. It just didn't want to handle the charging surge. Voltage doesn't really measure the battery state of charge you have to use a hydrometer to do that. Jim

Goofproof wrote:

sam1234 wrote:Well, woke up with the machine still running on battery power. The graph showed my pressure spike at 18. Battery level was at 12.1 volts.

Running time 5.53 hours, Pressure at 14.2 (range set from 10 - 20), leak 0, AHI 3.2, AI .1, HI 3.1.

I hooked the battery up to the charger. It said that the battery had a short. This was not what I expected. The battery has been sitting for over a year, with only one charge recently. I set the charger to recondition the battery. It then was able to hold a charge 12.8V, the same as I started. Whew!

We will see if it holds up to another use on my scheduled ride. I will check its voltage over the next few months. It may or may not. Fortunately, I have to rely on the battery only one night.

Odd's are the battery was so discharged that the charger was overwhelmed and showed a short. It just didn't want to handle the charging surge. Voltage doesn't really measure the battery state of charge you have to use a hydrometer to do that. Jim

Well, I took the battery to a battery store and it checks out fine (It is a sealed cell). I really only need it to work one night on my trip so all is well. Even if it doesn't survive, but provides enough power, I will be happy.

we found a female socket portion of a cigarette lighter plug which connects directly to (any) a 12v battery source, we use this with the 12v DC power cable which has a cigarette lighter plug on it, we find this set up useful for a camper or a boat as it can be connected to a car plug or a battery. it's also great when the power goes off at home.

Ms Piggy wrote:we found a female socket portion of a cigarette lighter plug which connects directly to (any) a 12v battery source, we use this with the 12v DC power cable which has a cigarette lighter plug on it, we find this set up useful for a camper or a boat as it can be connected to a car plug or a battery. it's also great when the power goes off at home.

The female socket that you describe, is exactly how I have connected the battery to the converter. Thank you