FairTax4me

I bought a 6 cell EnerG 4200 stick pack form Promatchracing.com to try out. I've seen a few people asking if these are any good, but haven't read much from people who've tried them. So I decided to give one a go and see how it stacks up against the 4600.

Today I did the first run on this brand new pack. Charged to 4000 mah on the Ice charger at 2.5A, it comes with only a surface charge to keep it alive during shipping.
This is in a Traxxas Rustler VXL. 84/20, 2.2 Gladiator tires. approx. 50/50 off road (smooth dirt, and some deep grass), and on road for periodic speed runs. Outside temp was 85°.

Top speed: According to the readout on the DX3S radio, it reached a top speed of 31 mph. (My Duratrax 3600 barely made it to 25, but it's in bad shape from sitting around for a while, gonna cycle it a few times so I can have something to compare to)

Total run time: 19 minutes 35 seconds. This excludes time spent walking to flip it over after a roll, free it from obstacles, or waiting for cars to pass on the street. I ended the run when one cell in the pack reached 150°. The rest of the cells were within a 5 degree margin of that temp, which ain't half bad for the first run.

Average cell temps (in °F) at approx. 5 minute intervals. Off charger temp was 125° average with a 6° margin. About ten minute break between disconnecting from charger to actual start time.
Beginning of run temp 115° with a 4° margin.
At 5 minutes 122°, 5° margin
10 minutes 130°, 5° margin
15 minutes 135°, 4° margin
End of run average temp was 148°, 5° margin

Start voltage was 8.5V, end of run voltage was 7.3V. I didn't check voltage any during the run.
It will do wheelies with this pack. It did get a bit difficult as the run went on, but even at the end it was still able to pop the front wheels off the ground under full throttle from a standstill.

All in all I'm pretty impressed for $25. I'd say its definitely worth it for an inexpensive bash pack. Lots of power in these cells, though not as much as the 4600s. I'll try to update this after a few more runs, and maybe get a few pics of the "test area" and the temp gun and speed readings. I'm also going to try to get this Duratrax pack in shape, though its future looks a little grim, and pick up a Venom pack and something else in the 4000 mah range from the LHS so I'll have some packs for comparison.

Brainanator

My Feedback: (1)

I also got a 4200 6 cell pack for my slash. Still waiting on my charger. I got a 4200 7 cell pack as well, so I'll see what's what. But I don't have a temp gun, nor a volt meter where I'm at...

but thanks for the detailed testing, let us know how future runs with the pack go.

airmayle

Great review. I just picked up some 4600 from pro-match and they are the best cells I have. I think I will try some of the 4200 packs, can't beat the price. If they are like new 4600 you will need to cycle the pack a couple of times to get the full power of the pack.

FairTax4me

Just finished it's second charge at 3 amps.
4250mah.
I forgot to set it up to discharge before I charged it, so it should hold more. Looking forward to running it tomorrow.

Brainanator

My Feedback: (1)

quick battery question here: Is it bad to not charge a battery fully before using/discharging it? As in, you charge it half way, then run it.

FairTax4me

Isolated occasions that's fine, but don't make a habit of it. It can bring down the packs overall voltage by not getting a full charge. It can also lead to cells that are out of balance. Meaning one cell might discharge significantly faster than the rest, and could eventually lead to a dead cell.

Brainanator

My Feedback: (1)

I figured it wasn't "good" for it, good to know it's not really bad for if it does happen at one point, thanks fairtax4me

littleazn248

quick question i just got my 4600 and Im curious do you need to equalize the packs? Also after I charge and run it for the first time how much do I run the car till i stop ie. till the batteries die? Then after that do I need to wait before I charge them again?

Thanks

FairTax4me

Promatch has instructions for charging all of their cells on the website in the FAQ section.

You don't have to equalize them but it will help battery life to do it every so often.

The first run you ill want to keep an eye on your battery temperature to be sure it doesn't over heat (the 4600s shouldn't with most motor setups). If the battery gets hot to the touch (approx 140°) then it's a good idea to end the run and let it cool. Always let the pack cool completely before doing any discharging or recharging. You will get more power out of a pack that is slightly warm off the charger, but don't run the pack if it's hot until it cools off some.

FairTax4me

Round Two!

Finally got the chance to run it again today. Didn't have the temp gun with me, and I forgot to set the timer until I had already been running a few minutes. So no exact times or temperatures this time.

But it did run for about 20 minutes with plenty of power the whole time. I did end the run again due to battery temperature. It was in the 140° range, and I kinda had to get back to work (was on my lunch break) .
Top speed this run was the same 31mph. That was actually acheived after running for about 4 minutes. The first speed test was right at the start of the run and was only 29 mph. Reason why: the pack was completely cool at the start of the run. All batteries discharge better when warm. After running a few minutes the pack had warmed up a bit and was able to release more of its stored energy to the motor.

Cycle results!
After the run discharging at 3 amps to .9v per cell took less than ten minutes so the pack was pretty close to dead. Recharging at 3 amps it took in 4414ma. A few more cycles and that should go up still.

Dialed_In

Thanks FairTax4me,

Very good information. I've been curious about these batteries and if I stick with 6 cell NiMH batteries I will probably grab a couple.

KCMike

Great write up! I've just purchased this battery but have yet to try it out.

Brainanator

My Feedback: (1)

praying that my charger comes in the mail tomorrow. Then I'll get a good run in on this pack. Won't be super detailed like FairTax4me's, but I'll be able to compare it to a sucky battery I have...lol

Brainanator

My Feedback: (1)

Alright, I was wondering how far dead I should run the batteries. Like, should I run them till they can't move the truck, or should I stop as soon as they hit the drastic loss of power? I don't have a discharger (at least I don't think the onyx 230 discharges), so what do you recommend for improved battery life? (with NiMH)

FairTax4me

I don't think any of the Onyx chargers will discharge, but that's OK. It's not 100% necessary to discharge a pack.
You only want to run until you notice a big drop in power. Continuing to drive past that point will generate more heat. And with Nimh packs you generally don't want to go below .9V per cell. It won't catch on fire or anything like a Lipo, but it can damage the cell and cause it to not hold a charge.

Brainanator

My Feedback: (1)

Awesome, that's just what I did, since my charger is here! Thanks again FairTax4me! (and it does not discharge, but like you said, no biggie)

Chris_RC

I got a 30 amp Integy discharger used on ebay for $7 shipped. might want to look at one of those. Or even better, a Novak Smart Tray. Those go for about $20 shipped. I got mine for $17 shipped. Smart Trays go higher on ebay though. I got mine off the rctech fs/trade forum.

littleazn248

ughh this promatchracing.com place is annoying!!! I ordered my packs got them ,ends up they were the incorrect order. Jeff's been saying he'll send out new ones but I haven't even gotten the tracking number yet. My summer ends in exactly one month