Rsickles

iTrader: (21)

Actually before I switched brands, I ran the Protek hump lipo in my nitro Ofna. It was also a rear mount, just as close to the engine, same temperatures... It never, ever puffed. I ran it for more than three times the life of any of my Protek flat packs before giving it away to someone else after I switched! If only that style fit on my cars, I'd go back to it. It was honestly a great pack! It just seems like the flat ones are garbage.

4.2 a cell. Do you think they'd be capable of discharging only down to 7.3v/7.2v after an hour and a half if they weren't getting full charge? Here's my setups:

Setup 1:
-2300mah 8c Protek flat Rx pack (unregulated)
-1267 Savox steering
-1267 Savox throttle
-KO Propo 407s Rx

Setup 2:
-2300mah 8c Protek flat Rx pack
-1256 Savox steering
-1267 Savox throttle
-Orion 10a regulator, set at 7v output
-KO Propo 408s Rx

Dave H

I don't know how long it should run those setups, I was just comparing the 1000mAh charge to the 2300mAh rating.

RCMD

iTrader: (1)

Last night I did a quick test on an old puffed recover pack I had in the house. My good nitro receiver packs were still in my trailer and did not feel like getting them out.

I found an old 2200 Protek receiver pack that was only 3c (?) likely several years old. Only rated of for 6.6a continuous discharge. Charged in a lipo bag in a metal tin - usually do not charge puffed packs. Then hit it with a 8amp d/c down to 6 volts. After it stopped, the resting voltage was 7.6 volts. I was not expecting that but never messed with rating lipos or low mah packs before. I actually had expected to see a number somewhere in the mid to low 6 voltage range. My good batteries with either 5c or 8c ratings will likely yield better results, but I doubt they will dip beyond 7 volts on a continuous discharge.

Given that, I have to say there is definitely some truth to what Dave is saying and there is a definite possibility you could be over discharging your packs.

This method is flawed though because the max burst d/c should be less than 8amps and this was done at 8amps continuous. Continuous discharge is likely only a few amps while driving. Voltage is also measured at the end of the wires and not at the pack itself and likely underestimates the true battery voltage.



I have to believe your packs are dipping below 6 volts under load and causing you packs to puff. I still think heat can definitely play a role in the packs puffing or at least contribute to it. Something else that just hit me is if your servo endpoints were not set right and locking it would further increase the amp draw and could also contribute to an over discharge situation.

Rsickles

iTrader: (21)

Definitely some good info or ideas here.

What charger are you running 8a discharge with?

I'll do some testing tonight and see what kind of draw I get under idle and peak. I'll establish peak by locking the front wheels and let the servo saver take the deflection, as well as apply full braking on the throttle servo.

So there are two likely theories here: The first is over discharging the pack and the second is overdrawing C rating.

The first idea about over discharging it... If the continuous discharge works out to only a few amps, then I can't really think it is possible to discharge down to 6v/cell and jump back up to ~7.2.

The second idea about max draw. I believe that max draw is way less than 18.4 amp limit (8C x 2300mah) on the packs. Likewise, on my other setup with the Orion regulator, it is 10a max anyhow.

Will report back later.

bigjayjay1

iTrader: (86)

Ive had the same experiece with protek lipos when I was running durango went through three.

RCMD

iTrader: (1)

Turbo 35 - leftover from the NiMH days

racerjerm

iTrader: (1)

I've had several Protek Lipo 1000 and 2000 packs in buggy and truggy, that ran for two summers that never puffed or died. I would charge between pratice, heats and before mains. And would leave stored at full charge. I even left them over the winter at the full charge state and they worked fine the next year. In fact I always left them stored at a full charge state. All but one of them finally died when I left them stored for over a year without touching them. New RC racer was born... But one of the 2000 is still working though!

Rsickles

iTrader: (21)

Thanks. I've good luck with other Protek LiPo's before too.

This thread was more about these exact LiPo's (2300, 8c, flat-style).

Just to update... I've now started charging the packs after about 30 minutes of use (not continuous use) - under the assumption they were being over discharged. Should see in another couple races if they'll last.