| josh_smaxx |
24-07-2007 09:36 AM |
Heres my review, i did it for another forum so if it has any wierd, random letters in it is probably off smileys lol.
Quote:
After a while of waiting i give you the EP4200 matched 6 cell pack review.
EP4200 6 cell matched pack from demon power products
After some problems with my IB3600 stick packs and after they fell apart I decided I would start searching high and low for the best sub-C NiMh cells money can buy, iv been racing electrics properly for a few months now, gain a substantial amount of equipment and am set to continue to race them for a long time, so I though it would work out better if I got some top notch cells.
Now, my first idea would be IB4200 WC matched cells, rated as the best cells money can buy. After hours of research through websites, racing forums ECT I came to conclusion that this is not true, they apparently are extremely fussy to look after and the newest batch are only good for 10 cycles before drastically reducing performance. So these were out of the question.
I then found www.rcracechat.com and spent hours in the cells/chargers section to see what the top national drivers on there used, allot of people were moaning about IB4200 WC cells, allot of people were loving them, but at £40 a pop it was going to take me a while to get the extra money I needed (I had £100 to spend on cells). then I was directed to the East Power (EP) 4200mAh cells that are BRCA legal by our very own Dagger Thrasher, I then found all the threads on other UK based forums which quickly lead to show me that they were rivaling, if not beating the IB4200WC cells, so I spent another few hours shopping around and then came across Demonpowerproducts.co.uk...................
A fully assembled set of matched EP4200 cells with just wires (no connectors) will set you back £32.85
To good to be true I hear allot of you say? Well that’s the first thing that came to my mind as well, yet allot of people from various UK race forums have purchased there EP4200 cells from demon and are over the moon with them, but one thing stood in my way.... the 'out of stock' label
One phone call later tells me I can order them and at latest they will be here just after the weekend. Spot on, gives me time to get some new tires.
I wake up to find a nice large brown package sitting on the floor in my porch hidden behind touring cars, hauler bags and everything else RC. I quickly hurdle over my hauler bag, grab the package and jump back, dashing into the living room to open it, even though it was addressed to the cardholder I knew it was mine. First thing I noticed when I opened the package was just how well protected its contents were, it was lined in bubble wrap and the contents were packed in tightly with more bubble wrap, these weren’t going to get damaged in transport. So I pull out all the bubble wrap to see 3 perfect sets of EP4200 cells, all with rather impressive matching labels (the numbers were impressive, no art work here) and nicely assembled with silver connecting bars and high quality silicone wires. I had specified just wires and no connectors as I apparently soldered my deans + to -, doesn’t matter, they still function the same. Each set of cell were neatly presented each in there own clear plastic bags so that they didn’t short out when in transport, this is one fault I see is I would like the bags to have been re-sealable so I didn’t have to buy a battery storage box. First things first and that’s to put some connectors on, cue bring out the soldering iron…. I get the iron out, something magical happens and iv finished soldering them before you can even read about it. Right, now connectors are on and the charger is out, these cells being matched cells already have been cycled when matched so they are ready to charge and use, perfect, the race tonight will decide weather they are up to high drain brushless racing or not.
The cells are all presented very well, soldered very smoothly and very tightly, the wires are long, I didn’t bother cutting them down yet. They are put on so the matching labels face up. The numbers on the labels are probably the most impressive out of everything on them, all 3 packs the cells are matched at 1.30V, now this is an absolutely outstanding number for cells that are pretty much unheard of. The rest of the numbers are good to, I won’t go into all this, the pictures will do the talking. Now with one pack on charge as I write this we will soon see how these packs perform with the street test.
These things are quick! The charger went off, I unplug the cells and got them locked and loaded, plugged them in, turned on my transmitter and then turned on the mamba switch….
So I took it out side, placed it at the end of my drive and blipped the throttle, the car whizzed off the line like that I have never experienced (granted, I have never had the privilege of testing high performance cells before, just IB3600 stick packs, I thought I was impressed when I first used them). I was running for a good solid 6 minutes without any loss of punch what so ever, although I was expecting this seen as though they are matched cells I was still amazed at how much power these cells can kick out for the time they can. Things ended with a nice head on into a curb…. Just cracked the servo but a bit of CA glue soon sorted that. So I brought the car back inside to asses the damage, nothing to major else where. Now bearing in mind these cells where fresh of a 5A charge, they were warm when tested, been ran hard for around 6 minutes and when they cam off they were barely any warmer than when they came off charge, I have to give it to these cells, they do perform! But the proof is in the racing, which will come tonight in a unlimited 2wd class, anything goes except LiPo, I am running a B4 with mamba max 5700 and matched EP4200 cells, spectrum radio gear and it is well set up, no excuses then!
I started the night with all three sets of cells fully charged, arrived at the track to find it almost empty! So I unpacked, put #1 set of cells in and went out with my friend who is running a B4 with an 11x2 in, last week this car was slightly slower than mine down the straights, now I notice a huge difference, the way this car pulls away now is phenomenal, because I was only running on stick packs before, they was so much resistance in each pack it slowed all the punch down, now these cells are top notch and the soldering is perfect the punch gets there very smoothly indeed, and what a punch it is! I new Id see a huge difference with cells matched at 1.30V at 20A (works out at about 1.25 at 30A) but this was beyond me. The first round I have to admit, I was just getting used to it all, so I finished 3rd which wasn’t exactly spot on, still, 2 more rounds to go. With 5 heats after mine I had plenty of time to play with the car to try and get it to come out of the corners properly to show the true colours of these cells. Second round I had just repeaked #2 set which gave even more punch thus me only finishing 2 laps before a lower eye on a rear shock gave way. 3rd round saw still no driver improvement but, as noted by several spectators, my car was the quickest on the track, of which it wasn’t last week. The final saw some driver improvement on my behalf and I managed 2nd, I came back on after marshalling the next heat showing my car was as fast, if not faster than a B4 with Novak 4.5 brushless motor and matched GP4300 cells, I can put this speed increase solely down to the cells as I have done nothing else to make this car go faster.
As I stupidly didn’t check what the cells were taking in when I first charged them this is what pack #1 took in after 6mins of run time and stored overnight: 9.486V and it took on 4084mAh, so its fair to say these cells hold a fair bit of juice! On a discharge cycle at 1A from fully charged down to 5.4V per pack these cells are kicking out 4876mAh and my charger couldn’t get them fully down to 5.4V, they insisted on 5.9V for some reason!
Now, as you will probably of realized, I am really fond of these cells, I do recommend them, and I am sure you will notice a difference over pretty much any other cell you have tried. I know I was impressed by the labels, and everyone else was impressed by the labels so I am sure you will be too!
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