Trakpower Li-Po 4900
 

Got mine today from Microtech. The reason I bought this one is because it had the in-built corally connectors. I will be running it on Friday night at club.

So far it looks excellent! Really nicely packaged, and feels solid. Doesn't feel any lighter than my GP3700's at present, but I will stick them on the scales tonight to compare!

Mark

when will this be legal at nationals this technology is awesome used one at coventry same pack all day no hassle just top em up angd go so much power and convenience :thumbsup::woot:

Depends when someone propose's it for the AGM and it gets voted for, hopefully this year :thumbsup:

defo nimh cells are history

The Li-Po weighed in at 266g, with connectors, and casing, while the GP3700 slammed that with a whopping 416g!!! What a fat bastard!

Well, I am looking forward to Friday at this rate, running the li-po all evening!

Heres to nice relaxed racing!

Mark

Can somebody clarrify this: To propose Lipo for the next AGM, do we need to propose the full ruling in detail? or just a "I propose we run Lipo to EC regs alongside SubC"

I say take the majority of rules already setup from the super-stock tourers, (who I think are using them this year). I think it states that they must be no thicker than the equivalent SubC Cell, and be of 2s1p formation (i.e. 7.4v).

There maybe more, but I haven't checked.

M

I hear what your saying Mark, and I presumed the same - but I want to know for certain so it can be done right.... can somebody confirm?

Your best bet is to email Charlie Chris, he will be able to let you know what you need to do

the tc lads proposed lipo be allowed and the eb take control on spec's , though you could ask the lipo saddle spec be allowed a higher height as most higher capacity saddles are taller due the the cells in them
if you restrict height to tc rules you restrict capacity to about 3200, you need around 30mm to get up to 4800 ish

I think that the electric TC bys have a capacity limit of 5000mAh but to be honest, I think that 3200mAh will be plenty in off-road, even for modified racing.

Although I have not had first hand experience, I have heard that the efficiency of LiPo cells results in a 3200mAh pack being more comparable to a larger capacity NiMH pack.

Chris, i think what will need doing will be looking at all the rules that currently defing the use of Sub C's, then propose amendments to that (or those) rules and see how it goes.

Should the pack change 'expand' slightly when fully charged, as mine has??? This was charged on a robitronic overloader, and has got very slightly warm to the touch.

Hope it hasnt fried...

shouldn't expand afaik - what were your settings on the charger?

I charged at 3.0A, on Li-Po Mode with it on CC/CV charge mode.

You cannot change this...

has it ever gone flat? ir below 6 volts?

if its a trakpower pack contact them asap directly

No not gone below 6v. This was my first time charging...:(

Tried ringing but no answer so have emailed them.

ooo errr

Mark

Have measured the pack now it is fully charged, and it has gone to 8.6v :cry::o:confused:

what to do...

Hmm..interesting.

My micro LiPo's have never gone over 8.4V..I think the EB have even set a limit of 4.2Vpc??

Id keep badgering Trak Power mate...better to be safe and not blow my face off tonight at Hereford :)

With regards to AGM proposals, all you need do is propose that you guys run LiPo's at the 2009 Nats, you could even add that they must be a max of 7.4V nominal and a max capacity if you wanted?

As long as its voted in (fingers crossed eh!) then the EB would sort out specs and whatnots

Apparently it is f***ed. I rang trakpower (Ian, nice helpful guy), and they seem to think the problem lies with charger being faulty. The pack only went over 8.4v at the very end. Now to dispose of it.

Couldnt have been the pack then I take it...?

Gutted man...are they gonna send a replacement or are you now screwed??

not totally screwed. I still have my gp3700's. If the charger is faulty, then I think they will replace the pack free of charge.

Sending the charger back for analysis to Microtech before replacement. Hopefully the charger is faulty, and I will be re-imbersed for the pack by Trakpower. Gutted, I had hoped to use it tonight.:(

Glad you are getting it sorted Mark. Not a nice experience for your first trial with Lipo's.

I'm a bit confused though mate, surely Trakpower would only give you a replacement if the charger wasn't faulty?

Why would they refund you if its your own charger that was at fault?

Well if I had setup the charger to be correct for the pack, and it didn't cut out at the correct moment (during charging), and I have bought a charger that was sold as being able to run li-po, then it wasn't my fault. If I had accidentally charged the pack on NIMH mode for example then it would have been my own fault.

I think what he means is that if there is no problem with the Trakpower lipo they dont really have any responsibility to replace it as the fault occured out of there hands due to another manufacturers faulty product, if thats the case then its excellent customer service from Trakpower to honour it :thumbsup:

Yes, I think they have taken pity on me, since I have done everything by the book...:thumbsup:

Yes, I agree Mark. I didn't for one second think that you didn't deserve a refund. It is not your fault at all. I was implying that it would be the robitronics responsibility, not trakpowers.

Yeah....
I am still not convinced its the charger though, since it was fine up to the last 5 minutes of charging (i.e. it did not go above 8.4v at any stage). I guess I could be in the 1% of battery failures that occurs.

Interesting - cos i know another guy that bought a brand new pack and Orion Advantage charger and he had the pack expand on it's first chanrge. Very strange.

when you get sorted, buy a trakpower balancer, that will terminate charge if the charger fails as it does more than just balance cuts out at 4.21 volts per cell
trakpower have a very good back up service, ask our very own jimmy on here!

did you notice what the amps were doing when it got to 8.4 volts?

how do you balance the 4900 while chargeing, ive just received an orion balancing system today, looks like you can only balance while not on charge...?

should be in line like this (click the cell balancing)

http://www.trakpower.com/Products/tpvbalcomplete.asp you may need a trakpower lead, james you should have gone gold!!!! it comes with all the leads and instructions and i can tell you what to do!

I see yeah, no lead in my system, im gonna swap to GOLD ;)

good man take it you have a lipo pack? you could have run one on sunday just gone had a spare with me

yeah 4900 mail order......

Never mind for sunday :eh?:

Mark, were you running the 4900 in a B4 or which car if not? did you need to modify anything if you were using a B4?

Plus sorry to hear of the problem you had at least its going to get sorted!

Matt

matt they fit in a b4 with no problem or mod what so ever