Solar system? (battery charging)

Hi, I searched the archives, couldn't quite find the answer. I bought the C 100 from cpap.com, and own a 13 watt solar panel system, with a regulator. I was wondering if it was safe to use this system to charge my battery? I have gotten mixed answers online, some people saying it will ruin the battery (because it's lithium). Does anyone use a solar system to re-charge their C100 batteries? The manufacturer sells a solar system, however, it is costly, and I already own a solar panel system. I am not educated on solar systems, so not sure if there is something special configuration that allows tosafely charge C100 battery? I called the manufacturer, and was sent to leave a voicemail.

Upper voltage control is critical for charging lithium batteries. You are looking for control to 0.05 volts. If your regulator can handle that and provide the proper voltage you shouldn't have any problems. If you can't and the voltage climbs up you can ruin the battery and possibly have it blow up and catch on fire.

Lithium batteries need a charger specifically designed for that particular battery. Fire or explosions can result if you don't use the right charger.

This isn't like the standard manufacturer's greed/liability warnings to use only their charger. Lithium batteries really do catch fire if the charger isn't right. Remember a few years back when Dell and Sony had problems with laptop batteries catching fire?

Some battery packs have built in chargers that take an external DC power source and convert it to the voltage and current needed by the battery. I don't think this one has that.

Many lithium battery packs have a safety circuit that helps keep track of the charge and will "self-destruct" and permanently disable the battery if it detects certain conditions that may indicate the battery has become unsafe. These circuits commonly detect the battery has discharged too far or has been overcharged. These safety circuits are the main reason modern lithium batteries don't burn or explode as often as older ones do. They are also one of the reasons people often find that their lithium battery is suddenly completely dead with no warning.

Thanks for the info, not worth the risk, just hope it will get me through 3 nights. Might be a generator there, could charge it a little withh that.

This is the regulator I have.

http://t.harborfreight.com/7-amp-solar- ... M6N0baOiDw

Dive Apnea wrote:Thanks for the info, not worth the risk, just hope it will get me through 3 nights. Might be a generator there, could charge it a little withh that.

This is the regulator I have.

That's almost certainly intended for lead acid batteries. Frankly, I'm surprised it doesn't specify that in the owner's manual.

FWIW: I spoke to the company that makes this battery, and they said that, the battery circuitry itself will shut off if it is being over charged, or doesn't like the charging system. He said that I cannot harm the battery. It needs 12-16V, so, I think that controller will help with that, depending on what the solar panel puts out. I asked what was different about their solar panel, it seems that it is specifically designed with a straight connection port, and keeps the voltage between 12-16. It charges in 4 hours, I am guessing because it is 40 watts, whereas, my solar panel is 13w. I am gonna use the battery tonight, and then test the solar unit I have. I honestly wish I could afford theirs, 2.2lbs, small, charges in 4 hours, (depending on sun). I check back when I test my solar unit.

So, 5 hours on the after market (harbor freight) 13W charger, and didn't charge at all. Probably gonna get their charger, they claimed full charge with good sun, since I camp baja, and CA during summers, I think I can get that charge rate, This will allow me to use humidifier too.

Thanks for the responses, helped me hake this out. Btw, something I didnt think about, is that the C100 does not come with a male cigarette lighter attachment. So, I purchased one from them to the tune of $32 , it will probably be useless, unless you camp, then, drive 4-5 hours to a new spot each night.

Update, Tried battery again (1\2 full) 10cm, was wrong, humidifier set at 2. Only got 5.3 hours, before it died. So, 15 hours total with 10 air, 2 humidifier. I think this battery is good for 2 nights, and no humidifier if you want to play it safe. I have a 6 hour road trip, so might as well test how long it takes to get each charge bar (4 total) charged with car plug. I'll check back.

Battery charged with cigarette car charger 1/2 full in 1 hour, then after 3 hrs 3/4 full, then fully charged 3.5 hours. Wondering if I hook up to my friends truck charger, then run truck for a bit, repeat, get me some extra hours. Pretty committed to the solar charger, but $279 is tough investment. Maybe It will make me camp more. I will post up solar charger charge times, when I get it. Hope this helps someone interested in this battery set up.

In case anyone ever wants to know all the possibilities. Final chapter, picked up BPS solar charger, nice compact and light.

Drained BPS 100 battery, hooked up to solar charger, 80º clear skies, socal weather.

Charge times:

1 hr. weak 25%

2 hr. 50%

3 hr. no change

4 hr. 75%

5 hr. FULLY CHARGED

Pretty pleased with that, considering, I now can use my humidifier, drain battery to 50% with nearly 10hrs sleep , then recharge back to full.
Used battery again, to get a 1/2 empty battery to see what charge time would be, as I would charge it daily. Again similar conditions, 80º clear skies, 3 hours noticed it was went from initial 1/2 full to 3/4 full, 20 mins laters, it was fully charged, so 3:20 to get it back to full charge from a half empty battery. YMMV.

It was an expensive investment, but going to be nice to not have to hook up to a marine battery, noisy inverter combo, not that there is anything wrong with that. I really got this for a yearly trip that requires a flight, but now have it for driveable camp trips, or if the power goes out here, which to be honest never happens. Also, would be good for backpacking in somewhere, super light battery and charger.

thanks for listening!

So after working great on 3 camp trips, on the 4th, battery died during night. I woke up 4 hours after going to bed, and it was dead after being fully charged, so 4 hours was the longest it would have lasted (not sure if it died earlier, I am heavy sleeper). Luckily, it was under warranty via cpap.com, was told 3-6 weeks for turn around.

I will post back if, when I hear back from cpap.com

I forgot to update this thread, sent battery back to cpap.com, and they tested battery, seemed to work fine for them. Took a four day trip, worked like normal, charging with solar charger. Then fine on another overnighter. Must nave been an anomoly. Thanks cpap.com.