Bieffe

iTrader: (1)

Ok after reading I know I have to stop playing when the combined voltage falls below 3.5v.

But how I know this? There is no display and stopping to unplug and check is tedious. What do u guys do?

Don't wanna end up all pregnant.

FT

iTrader: (2)

Individual cells shouldn't drop below 3.2v each. Ive set my ESC to cut-off at 3.4v, however the ESC is only cutting off based on total-voltage calculations, so if one of your cells are out of balanced, you might accidentally harm one or more cells. Note that some cells responds differently, I had Turnigy Nanotechs dropping to 2.7v and still kicking full punch and capacity after charging it up and continue to do so for many cycles later.

Many people use a lipo voltage indicator plugged into their balancing tab to display voltage and some actually left it attached all the time during play for easy read-out via the clear body shell's window. It is also becoming a trend to use a low-voltage alarm, works by plugging it into the balancer tab too, it's primary function is to beep off loudly when voltage drop below a set value. Some of these alarms comes with indicator built-in too. Optional - use a calibrated voltage reader/multimeter to identify the tolerance offset of the Lipo Voltage Indicator, not always they are accurate, some can be off by quite alot.

The best method Ive used so far is via estimate. I do not usually drain my cells all the way down to limits, I would normally stop playing after a certain estimated duration and upon checking, the voltages are usually at 3.8v, which is also the voltage range for long-term storage. And speaking of storage, never store lipo at max voltage, that will cause harm to it's chemistry, resulting in bloating and capacity/performance losses. By my understanding, a week worth of 4.2v/cell storage is ok but it is still chemically decaying at a rather fast rate. A month later, it would had deteriorated about 1 - 2%, up to 10% or more for lower quality packs.

Avoid draining the cells too low and too fast. Make sure that your discharge rate is well within the range of pack's Constant-discharge rating. Use multiple packs and switch regularly for long duration play time, it harms the cells if you drain it too much, even if you stop at 3.2v. Try to stop at about 3.7v for longevity sake, not a compulsory, just a good habit to practice.

ongbenghui

iTrader: (5)

if you are running EP, you should be using an ESC that support Lipo cut off that will slow the car down or cut off when the lipo pack voltage drop to a certain value. Check your ESC manual.

for GP RX battery, attach a battery monitor or those with buzzer.

Bieffe

iTrader: (1)

Thanks for all the feedbacks. Me noob. What is EP and GP battery?

twe75

iTrader: (6)

EP is Electric Powered GP i not sure maybe it meant the GP brand of rechargeble batteries .

My own 3s 5000mah lipos are really fully bloated and hard and i'm thinking of throwing it away after i get replacement before it turn my truck into a big fireball . And my lipo's are also getting longer and longer to balance charge . Simply love 3s 5000mah lipos as they leave a dust cloud behind my truck when it runs at full speed .

I also noticed that now my esc will cut off my lipo's at 7.6v for 2 s and 11.7 for 3s lipo's . I wonder why also .

FT

iTrader: (2)

GP = Gas Powered (Nitro Methane, Gasoline or other combustables), they use a Reciever pack to power the electronics onboard. For weight saving's sake, I didn't bothered with an indicator or alarm, just do a little math and experiment to indentify the draw rate then estimate a time to swap or stop.

twe75, it is very likely that your pack had been damaged so much that it's voltage sag is so extreme it triggers your auto-cut-off. Your ESC Cuts-off the moment it detects the lowest sustainable voltage from your pack during high amp draw. In your case of bloated packs, it is no longer able to safely discharge at it's stated rating. If it was a 30C pack, Id consider it a 1C pack now based on your discription of it's condition.

However if you would like to continue using ever ounce of life your pack has, consider playing without auto-cut-off. Once you realise a great performance loss then that's when you have to stop and charge it back up(at 0.1C). You will be able to continue to have fun for at least 15 more cycles. There will be a risk of ignition, so please charge it in a safe location and stop/reduce current whenever temperature is 2 -3 degrees above ambiant or if bloating gets worse.

twe75

iTrader: (6)

I already ordered 2 turnigy nano-tech 3s 5000mah 45c discharge from hobbyking . Hope it can last much much longer cos not cheap at all . FT any idea how to make a bigger battery compartment for my truck to accomodate 3s 5000mah more " comfortably " ? Currently its a very tight fit with the lipo bloated , when not bloated , its nicely fitted with no gaps at all but the wires will be a squeeze .

For the time being i try to use the 3s 5000mah lipo lesser . Once the new ones arrive , i will use it one last time to discharge it then throw away so that it won't cause any big fire issue in the dustbin .

FT

iTrader: (2)

Wow, those are very heavy packs. At 225amp discharge, I'm sure they can handle far more discharge capabilities than your esc and motor can ever draw. Id say, you had over-estimated for the choice of pack. I hope your truck can handle the additional weight, you are sacrificing a lot for an over-killed pack.

Well, with a ruler or calipers, make your measurements then you can estimate a good fit(you should do this before purchasing), otherwise some modifications will be required.

twe75

iTrader: (6)

Well other then the 120a esc , i also had 2 brushless fan to share the power with . 1 25mm 12v brushless fan dunno the ampere draw fan for the esc and another 5v 0.25a brushless fan abt 35mm for cooling the motor . So the current draw from the motor is definitely more then 120a .

I've just measure it , the new turnigy lipo is wider then the 3s 30c 5000mah batt other measurement stays almost the same . Rest is the weight , that will have to see how . I do not go track anyway . But if the track can handle the current 3s 5000mah lipo , i think the new one should be still ok . But frankly i do have modifications to my battery compartment in mind .