2 mins run time?

[bigdavevw]

Hi guys, i finally managed to take the RC10 out for a little spin today.
I took the car up the local woods, and was ragging it round offroad, i got 4 mins run time. So i put it on the fire road with a fresh battery, and i got about 2 mins run time, i wasn,t even thrashing it hard cos i,m a newbie and didn,t want to crash it.

The batteries are Turnigy 5000 mah 7.4v lipo batteries which read 7.49 v before i started driving.
The motor is a Trinity speed gems 2 sapphire brushed 17x1
ESC is a LRP reverse pro

I have checked the batteries, the voltage is 6.12v and 5.88v is there some kind of cut out on them?

Dave

[CAT3K]

7.49v seems a low start voltage.

When mine come off the charger they peak at 8.4v. Also 6.12 and 5.88 voltages are not good for lipos. I set my esc cut off at 3.2v per cell, so 6.4v per lipo. Anything below 6 volts and you can kill a cell, and then they won't charge properly.

If you have a balance charger see what the individual voltages are per cell in one of your battery packs. It's possible you've damaged them by running them too low

[bigdavevw]

Cheers for the info, i hope they are ok. Got one charging now. I thought that cos they are 7.4 volt batteries they should only be charged to 7.4v?
Dave

[soniccj5]

Each cell should be at 4.20V when fully charged. Most chargers you just need to set for LiPo 2s 7.4 and they will do the rest.

Fully charged LiPo should give you about 30-40 mins run time.

[Jay Dub]

Yeah, your batteries are not getting a full charge. -Jeff

[madweazl]

Like the others stated, 8.4v should be about where your batteries peak. A 5000 in most setups for buggies will yield a good 30 minutes of runtime. I can run on track with a 7.5t Tekin for at least 25 minutes at a race pace.

[THEYTOOKMYTHUMB]

Cheers for the info, i hope they are ok. Got one charging now. I thought that cos they are 7.4 volt batteries they should only be charged to 7.4v?
Dave

It's confusing I agree. I bought my first lipos about 2-3 yrs ago and the first time I charged them I thought they were going to explode because the voltage kept climbing and climbing and climbing... to 8.4v. And this is when lipo paranoia was very much alive and well.

Anyway, as stated above, hopefully the cells recover and you can have a lot more fun with that pack. I just added that so you wouldn't feel as though you were alone in your thinking.