LDM

My Feedback: (15)

new to electrics and trying to figure out the charging game. My charger is a Intellipeak Pulse charger.
ok for a 7 cell/ kr -600 ae I was charging at the max of 3.0 and the false peaks quickly then I reset and it will finally charge in about 30 miniutes(give or take )
then I tried a 8 cell 830mAh -i tried a trickle charge to break it in at 2.0 but virtually got nothing, Again I went to the max on the NiMh scale and turned the dial to 3.0. I check the heat and this time the batery started to get warm and based on my planes performance was fully charged.
Is there any science to this for dummys like me? I am confused due to cell size? differant amps, ect. Is ther a beter charger that takes the guess work out of this ? I really enjoy electric flight but dont feel I am getting the most out of the batteries?I was considering the charger from tower that sells for about $129.Lastly is there a good place to buy batteries I currently only use hobby lobby. thanks for all your help

Matt Kirsch

My Feedback: (21)

Well, as you've probably already realized, there is more to charging batteries than "Plug it in and crank the charger to max." The setting is there on the charger for a reason. Charge too fast, and you can damage the battery.

This is where the concept of "C" comes in. C is a term used to define the one-hour charge rate of a battery, and is equal to the battery's capacity. For example, if a battery is rated at 600mAh, then C is 600mA.

If you charge the battery at C, it will take approximately one hour to charge. If you charge a battery at 2C, or twice it's capacity, it will take about 30 minutes. 3C, about 20 minutes. 4C, about 15 minutes, and so on.

Now, depending on the size and type of battery, you have to be careful how fast you charge it. Car packs with large SubC cells can be charged as fast as the charger will charge. Smaller electric flight packs, especially NiMH ones, need to be charged at a lower rate to avoid damaging the cells. In general, you can charge NiCd cells at 2C, and NiMH cells at C.

2.0 (Amps) is not a trickle charge. 50mA is a trickle charge. You should be charging your 830mAh NiMH pack at no more than .8-.9 Amps, and your 600mAh NiCd packs at no more than 1.2 Amps.

LDM

My Feedback: (15)

thanks that really helps but can you tell me if this makes some sense I would say that 600 nicad is twice the number so that is where you are getting the 1.2 ? Then the 830 NiMa is close to one times the number and that is where you are getting the .8 or .9 ? So for Nicads is a safe bet to go twice the amps and Nimh would be once the number ?

Matt Kirsch

My Feedback: (21)

If I understand you correctly (I'm not good at deciphering IRC-speak, a little grammar would do a world of good here), you have the right idea.