Batteries and Chargers

[RC10th]

Just make sure you heed the battery warnings and understand how to charge/use them properly as they are quite different to NiMh.

Basic rules are as follows

Charge LiPo no higher then 1c... Basically your 4000's a max safe charge rate is 4amps.

Make sure your lipo cut off in the car is set to 3.0 to 3.2v per cell, or if you are running your old ESC's get a lipo buzzer. You can ruin your battery in one go if you run it down too far below this threshold.

Store your LiPo's at about a 60% charge. This isn't so critical as long as you don't store them fully charged (8.4v) or completely flat (6.0v) somewhere in the middle will do.

[harvey]

I've been using lipo's for a couple of years to bash on my track. I have a noob question about storage at full voltage: If I get caught with charged batteries after dark I always try to discharge some of the pack on my charger before the end of the night. Is this necessary if I'm going to run them the next day? Better safe than sorry, but it would nice to have a charged pack ready for after work.
Also, I have tried the cheap $2 lip buzzers from a couple of sources on my 25c batteries, and they definitely buzz constantly when the battery is dead, but also throughout the run, even at full charge. It is annoying, and I wonder if it's the low C creating voltage sag that sets off the alarm. It is easy to tell when the battery is low based on straight away speed, but if you're driving slow not so much. Anyone found a buzzer that is less sensitive to momentary voltage drop?

[yellowdatsun]

From what I understand you only need to "store" them half charged, as in....a month or more.

Me and my RC buddies leave them charged for a week or so at a time, and have never had an issue. I have a few that have been charged for a couple months, with no issues as well.

So, no, don't bother discharging them if you'll be using them soon.

[lmw94002]

Yeah, for 48 hours I don't think it'd be a problem at all. And as far as I understand it, for longer term storage you should leave them at ~half charge.

At the track I had asked what those guys do week to week... most finish their run and leave whatever charger is left on the pack as it is till they race again in 1-2 weeks. Any longer and they do a proper discharge and storage charge.