72Blazerod

Hi Guys,

I am brand new to rc'ing as of today. My son found Axial and Losi rockcrawlers on Youtube last year and has convinced my to by 2 used trucks. I have no idea what I'm doing with rcs, but they are fun!

Anyway, I just bought a "Hitech X1 AC Plus Multi-Charger" and I need to charge up two different batteries (separately, not at the same time) my son's and my own.

My battery is a: Enrichpower EP 1300 mah, 11.1V, 25c

My son's battery is a: Gens Ace 5300 mah, 2s1p, 7.4v 30c (ace30-5300-0201B)

I have switched the charger into LiPo BALANCE mode to charge the batteries, it is set at 3.3 amps and 11.1 V (3S) to charge my "Enrichpower 1300" battery. My question is, how do I know when it is charged? Should the volts be at a certain level? Is it a timed charge that will shut of automatically?

How will I know when my son's Gens Ace 5300 is charged?

I don't want to have a fire in my house. Any information or tips would be appreciated!!!

Thanks,
Rod

ThePanda

iTrader: (68)

3.3 amps is way to much to charge that battery at. generally you want to charge at only 1c. the charger you bought will stop charging when the voltage hits 4.2 per cell. 4.2-1s 8.4-2s 12.6-3s etc. the 7.4 volts is nominal voltage. you always what to balance charge lipo batteries, if you can. its not necessary to do it all the time. but if you don't then the cells can get too out of alignment in terms of voltage, which is really bad for example a 2s that has one cell at 8.4 and one at 7.6 would be badddd.

easy what to calculate c is take the capacity and devide by 1000 so your pack 1c would be 1.3 amps-what you shoud charge at. and your sons would be 5.3 amps max charge rate. (though i think gens ace can be charged at up to 5c)

72Blazerod

Thanks Panda! I feel better knowing that. Just a couple more quick questions:

1. Could I charge my son's battery at less than 5.3 amps, say at 4 or 5 amps?

2. While I was balance charging my battery (at 3 amps - oops! now I will only charge my battery at 1.3 amps) the voltage reading went up to 12.6 volts. Is that okay even though my battery is an 11.1 volt battery? (Should the charger have stopped charging the battery when it hit a lower voltage than 12.6v?)

Thanks again for your help!!

Rod

blis

Yes it's ok.
11.6 = 12.6 (4.2 x 3 cells)

LiPo will use maximum current set on charger and chase the voltage until it reaches the voltage (multiple of 4.2 as above). Then it will reduce the current until it's charged.

Be careful, they can be dangerous and LiFe, LiPo and LiIon all have different settings, trake your time and get to know the equipment...

Just like you are

ThePanda

iTrader: (68)

charging at lower than 1c is just fine. so charging at 4 or 5 amps is fine. the 11.1 is really a resting voltage. its like a discharged voltage. so if you were to discharge the lipo thats what it should be at(on your 3s). the actual amount that one lipo cell can hold is 4.2 volts. so when charging your 3s pack 12.6 is right.

its sort of confusing, i know.

many batteries can be charges at more than one c though, it really depends on the battery. do note though that high amperage charging can damage the cells and reduce the number of cycles the battery will hold. 1c is best.

ThePanda

iTrader: (68)

one more thing, don't over discharge lipo batteries. ever very dangerous. and it is a good idea to get a lipo safe charging bag. or have a bucket of sand that you can toss over the lipo in emergency.

asc6000

iTrader: (15)

The general rule of thumb is to charge at 1c.
However.... and I DO NOT recommend this until you get some experience under your belt. Some people are charging at rates up to 20amps, and with good reason.
http://www.rctech.net/forum/electric...-more-now.html
THE most important thing as panda said is to not over discharge the batteries. They can be ruined in one use in worst case. To prevent this you should check to see that the ESC is set properly for " Low Voltage Cutoff " or LVC...
I charge my batteries in a lipo sack and in an area that if it does blow no harm. Inside the bbq grill with the lid closed.

MonstarRC

Inside the bbq grill with the lid closed. wouldn't that be worse with no ventilation? and most bbq would be outside side in the sun right? or thought more a cool dry place an safe is best each to there own though.. and remember to charge on something heat resistance so leaving it on a book or stack a paper big no no..