Hi gang new to rc scene couple questions, if u leave lipo battery in rc car connected 2 or 3 week does it damage it? ,then try recharge straight away will make it worse? , I ain't got voltage checker or balancer.this was Xmas time, then today Feb, battery been out of car bout a month stuck it on charge and its charged in half the time as normal, is this OK thx muchly
Can't see any damage to battery

I always disconnect my batteries and actually take them out of the car for storage. This is so that I can store the LiPO's in the LiPO bag. I also always bring them to storage charge before they go in that bag. Short runs means they get discharged down to halfway, and long runs means they get brought up to halfway.

I'm not a racer so my bashing sessions are more than weeks apart so I play it very cautious. My batteries get stored for a while between uses.

I know that keeping batteries fully charged or fully empty is a bad thing for them, and they will start to puff eventually. When that happens, that's bad, and they should be disposed of.

If you leave it plugged in, it will slowly discharge, and if you leave it in long enough, it can even drop below 3.0V per cell, which can (and eventually will) damage or even kill the battery. So I recommend to always disconnect the battery. (Even better and safer would be to take the battery out and store it outside the car, putting it into storage voltage before putting it away.)

LIPO batteries can become unstable at low voltages. If you leave it plugged in, the voltage will slowly decrease, potentially resulting in a battery fire. Burning your house down is not worth the few seconds it takes to pull the battery. Similarly, balance charging is critical to prevent the cell voltages from drifting too far apart and also creating a stability issue / fire risk. Most battery fires seem to happen due to physical damage, leaving them in vehicles plugged in for long periods, or charging mishaps.

Primary rules of LiPO safety:
1. Always unplug the battery when not in use
2. Always balance charge
3. Store the battery safely
4. Don’t charge while unattended

The reason you should disconnect your lipo, is that many ESCs that have capacitors also have a discharge resistor to discharge the capacitors when not in use. So what happens is the battery charges the capacitor, the little resistor puts a small load on it to drain it and the battery maintains the capacitor charge. During the course of using it during a day, it's so small you'd never notice. But if left it for days or weeks, that small load will eventual drain your lipo.

Not all ESCs have this setup, so your results may be different.

Lipos are super slow self dischargers. Meaning they will maintain a charge for months. I have lipos I don't use anymore, but every couple of years I check to see if they are still OK, and they are still very close to the storage voltage I left them at.

ESC's do not disconnect the battery. The switch on an ESC only turns off the BEC, the rest of the ESC is still powered and will drain a battery if not disconnected.