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Old chargers and mAh ratings?

Posted: Thu Feb 09, 2017 7:46 am
by PerKr
Dug out the battery stuff I got with one of my cougars. Basically an unmarked black stickpack, a 1500mAh saddlepack and a kyosho quick charger. Memory tells me there are more NiCd cells somewhere... The charger does puzzle me a bit. the front plate says "AC 7.2V - 1200mAh Quick Charger" and "No. 2232". I just don't get the 1200mAh thing. Unless it's timer-based, how would it know whether it has put out 1200mAh or 1500mAh? And if it's timer-based, how would it avoid over-charging? Unfortunately I don't have a manual for it and google is not helping.

Re: Old chargers and mAh ratings?

Posted: Thu Feb 09, 2017 8:14 am
by matt1ptkn
Could it be as simple as it puts out 1200 mA per hour? As in not a total capacity, but rather a charging rate. If its timer based, it won't know if its overcharging. That's what makes NiCds and 15 minute quick chargers such a fond memory. :lol: :roll:

Re: Old chargers and mAh ratings?

Posted: Thu Feb 09, 2017 10:15 am
by Lonestar
PerKr wrote: Thu Feb 09, 2017 7:46 am I just don't get the 1200mAh thing.
This is either irrelevant (my belief)

OR

the charger pumps out 5A meaning 15mn gets your to a full charge (I doubt it)

Check out the specs, they must be written somewhere, maybe molded on back itself?

Re: Old chargers and mAh ratings?

Posted: Thu Feb 09, 2017 7:02 pm
by RC10th
Best way is to just charge till battery is quite warm irrelevant of specs.

Or break out the multi meter and watch for the voltage drop, but who's going to do that these days. This would be helpful if you wanted some "data" on time to fully charge your pack. Also you could use your multimeter to see what the output of the charger is actually charging at if you wish for more info.

Many timer chargers you had to add extra time to get a full charge anyways.

Re: Old chargers and mAh ratings?

Posted: Thu Feb 09, 2017 7:27 pm
by jwscab
It did exactly that. Dump out approx 1000mah worth of charge in 15 minutes. If you had 7 cell packs you usually added another 5 mins or more.

Nicds were tough.

Re: Old chargers and mAh ratings?

Posted: Fri Feb 10, 2017 10:01 am
by makoman1860
jwscab wrote: Thu Feb 09, 2017 7:27 pm It did exactly that. Dump out approx 1000mah worth of charge in 15 minutes. If you had 7 cell packs you usually added another 5 mins or more.

Nicds were tough.
Yes and they still are! I was pretty early into the use of lithium-Ion batteries for electric flight back in about 97, and for that application the big benefit was weight savings. But boy were they touchy. If you wanted them to last more than 18 months you had to be sure to store them at 50% charge density, in the fridge, couldn't discharge them more than 5C or below a certain voltage, and I still had more than one randomly go nuclear. They have since gotten much better in some aspects, not so much in others. My smaller flight packs only seem to life for about 70 cycles in 12 months before IR goes up and they cant pull like they used to. Nicads not pushed for racing use seem to have an almost unlimited lifespan if treated well, as I am still flying Sanyo600AE packs I made up 16 years ago with almost no drop-off. The newer low self discharge NiMh batteries are really slick in some applications. I rebuilt the battery pack for my trusty milwaukee cordless pitbox screwdriver using LSD 3000mAh sub-c cells and it has been fantastic. I charge it maybe twice a year as the cells retain 85% of their charge after one year, its always ready to go. Every battery chemistry has its place and use for sure.