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View Full Version : Over-charging batteries - popping sound/liquid leaking...


mdowney
2010.12.10, 04:49 PM
OK - I followed EMU's advice (as I understood it) and charged an R1 750MAh cell at 1000MAh using my Maha C9000, left it sitting in the charger for less than an hour after it had finished, then heard a light popping noise. When I pulled the cells from the charger they were pretty warm and one of them had leaked fluid from the top (+).

What happened?

rajiex
2010.12.10, 05:31 PM
One of the batteries vented, I believe EMU said to charge at 1C (C stands for capacity). In the 750 case, is .8 A.. Dont get me wrong I have charged most of the time at 1 Amps also with no problems. but poo poo happens.

blt456
2010.12.10, 06:05 PM
OK - I followed EMU's advice (as I understood it) and charged an R1 750MAh cell at 1000MAh using my Maha C9000, left it sitting in the charger for less than an hour after it had finished, then heard a light popping noise. When I pulled the cells from the charger they were pretty warm and one of them had leaked fluid from the top (+).

What happened?

Some batteries vent when charged at some rates. When I buy r1 750's I usually charge them at .5 amps and discharge at 2 amps, and repeat the cycle a few times. Then, I normally charge the batteries at 1 amp and I've used the same batteries since 2009. Some of my r1 750 have started to vent on me, but only 2 out of 20.

mdowney
2010.12.10, 06:45 PM
OK - I guess I'm getting confused by "1C", ".5 amps" and "2 amps" as they relate to the Maha charger. As far as I can tell, the only choice I have is MAh. I what MAh would I set for "charge" if I want to charge the R1 750MAh batts?

Learning about electrical units of measurement would probably be a good time investment for me. ;)

rajiex
2010.12.10, 06:58 PM
OK - I guess I'm getting confused by "1C", ".5 amps" and "2 amps" as they relate to the Maha charger. As far as I can tell, the only choice I have is MAh. I what MAh would I set for "charge" if I want to charge the R1 750MAh batts? Learning about electrical units of measurement would probably be a good time investment for me. ;)

I am a newbie so take this with a grain of salt. C= Capactity.
If u got 750 charge at .8A or what the charger says is 800.
If u got 900 or 990, you can charge at 1000.
When u want to drain the charge in the battery, use discharge at 2000.

You can charge at a lower rate than the battery rating for a longer lasting charge. A little higher charge will give u more punch (faster car for the first 5-10 minutes but then it slows down and doesnt last as long as slower charge)
Read the other threads under batteries, charger and discharger. good stuff, i still dont understand all of it yet.

blt456
2010.12.10, 07:40 PM
OK - I guess I'm getting confused by "1C", ".5 amps" and "2 amps" as they relate to the Maha charger. As far as I can tell, the only choice I have is MAh. I what MAh would I set for "charge" if I want to charge the R1 750MAh batts?

Learning about electrical units of measurement would probably be a good time investment for me. ;)

For r1 750 I charge at 1 amp. 1 amp = 1000 mah. When you put a battery in a maha c9000, the standard charge rate from the factory is 1 amp. You can adjust the charge rate from .1 - 2 amps on it. I charge mine at 1 amp, and they have worked fine for over a year. Sometimes people just get a bad battery, so I buy a few packs when buying new ones.