I have a 6.6 volt in my M12 - at what voltage should I be charging it?

When I raced back in the day, I was always super paranoid about TX batteries because I broke a gas truck badly when my cheap radio died.

That said - how low is too low?

Should I keep a backup, or do they charge relatively fast since they're such small MAH? (I have the reedy 1300MAH)

6.0V is as low as I go.

+1. 3v per cell on life 3.4v per cell on lipo.

I pretty much charge my LiFe battery after every day of racing. It will last an entire day though. It does take a while to charge though. At 1C it take almost an hour.

I used for my 4px a 1450mah life pack, the manual recommend to stop using at 5.8 (2s) or 2.9 per cell, because life batteries after certain point drops insaly fast I think is after 3.0v per cell, the good thing is that you can abuse them a little bit more than a lipo but still not to much.

As for the car I used the same just because my servos are low voltage and the 6.6 are perfect I used the same 1450mah and usually it helps me get through practice,q1, 2 races of 12 min each and then change for the 25 min long one

I usually charge them until 3.39 each cell and had no problems.

As for the charge you can use 1.3c or 1c and it takes a little bit longer
Mine charges really fast like for example a 2s it drops to 2.9 per cell and the fully charge say 3.39 per cell it takes around 10 minutes or less depending on the c rate

1450 at 1.4c it takes 10 minutes more or less
At 1c a little bit more

Hope it helps

In theory, at 1C any battery will charge in 1 hour, at 2C it will take 1/2 hour, at 4C - 15 minutes and so on. So I suppose you have a problem if your battery is fully charged in 10 minutes, probably it doesn't have the same capacity as new

A 1C charge rate takes one hour for the entire battery's capacity. The batteries are not drained that far. Thus recharging takes less than an hour at 1C.

I agree with you, however, to fully charge a battery with 1C in only 10 minutes means you'll charge about 1/6th of it's total capacity. And I would say that's pretty far away from normal. I have some new batteries 4.400mAh and I charge them at 10A, roughly 2.2C, and it takes about 30 minutes to a fully charge. Which means exactly 1 hour at 1C. Actually, the battery capacity is given considering maximum tension (4.2V) and the absolute safe minimum of 3.4V and not 0V