GM LIPOs?
 

Anyone using them and in particular the LiPo V-MAXX 35C 5000-7,4V model?

Looking at these, speed passion or Nosram for a Cat SX with the stiff chassis which takes the humps

No, but we have the new EPIC 5000mah 40C available now which look really tastey Mike and cheaper too than most of the others on your list........

http://www.teamepiconline.com/cart2/.../TEP2000_L.png

Are they BRCA legal etc as I am hoping to do some events later this year and definately next year

What C rating batteries are you running?

Also how much are they as I can't see them on your site

i have the GM 5000 35C pack Mike. They are awesome, mega punchy. They are also flat bottomed so you don;t need to worry about the chassis with the retainer slots cut in it.

you certainly won;t be disappointed with them. Same spec as the Nosram and Speed Passion, but about £20 less

They are being submitted to the BRCA now for the next available homologation (January) but all BRCA events for this year have now finished so you wont have any worries there. They should indeed be legal in time for the next "BRCA" event which will come around early in 2010.

This year I have run the Vampire 30C 5200's (which have been superb and used by lots of our team including Tom Cockerill to win the Blyth National with) although I will use some of the EPIC 40C's next year for certain as well for even more POWER!!!!

These too are far cheaper than the Nosram's, LRPs etc but these are also 40C too (unlike the GM's which are 35).

They will be added to the X-Factory UK site in the coming week or so and then expect them to be available through all of our dealers stores as well as through ourselves via the DMS site too shortly after.

Have they got locators on the bottom?

Cheers :)

The stiff Cat SX chassis is already on order :)

get one of Northy's carbon cell retainers for the cat, they are ace

Already got one and using it with my Trakpower 3600s and Orion 4800. Wanted to try the stiffer chassis. I used to have a Vampire LIPO and was going to get another

Will keep the standard chassis as a spare.

do you like your car ultra twitchy then? The stiff chassis will make is even more direct and lose any forgiveness the old flexible one had!

I thought about that, but spoke to some of the Schumacher chaps and it's not too much of an issue.

I don't think I'm at a skill level to really notice.

Sorry to hijack this thread, but can you charge the GM Lipos on the Bantam BC6 charger using just the corally connects without using the connectors which ship with the battery?

thx

Danny

the GM lipo takes standard 4mm banana plugs and a 2mm central balancing banana plug. I have a BC6 and just use the standard trakpower balancing connector designed for their cells which has the 2mm central banana on.

DThanks Jim !!! What settings do you use the balance charge? What Amps etc? Do you find the balance connector a tad tight? Also did you remove the clear plastic wrap from the lipo?

thx

danny

yeah, take off the heat wrap, that's just the packing. the balance connector is a little tight, but wedges in ok.
I charge at 5A which is the max the BC6 will pump out, and is also 1C for the cells. worked like a charm so far

Thanks Jim this worked for me! I was wondering why you charge with 1C for the cells when GM LiPo is a 2 Cell battery?

The GM lipos are very good. The "C" rating on all of them is difficult to prove, and to be honest you can't compare 100% across different brands. We tested a variety of 35/40C lipos - and the GM was easily comparable with some 40C rated from other manufactures.

Think I may have to re-think what I go for, think it may be worth saving my money and not changing the chassis and getting a pack or two of the GMs

What chassis are you running in your Cat?

I have the stiff chassis on my cat. tbh, the only reason was the lipo locations - at the start of the year, there weren't any good lipo's out there that were flat bottomed - and I needed a lipo chassis, so didn't want to order the one that forced me to run flat bottomed lipos.

I haven't tested back to back the chassis. However, I am running with a softer (cut) top deck, to get some flex back into the car.

The 'C' rating is derived from manufacturers testing their batteries at varying loads and comparing the voltage drop. If a 5000mAh cell is at 4.2V, (under no load), and if under a load of 200A it drops to 3.9V, some people may say that 3.9V is still an acceptable level, and therefore it has a continuous 'C' rating of 40C. However, someone else may say that for continuous, a cell should hold 4.1V/cell, in which case the same Lipo would not be 40C, and would infact take, let's say, 150A. This means a 'C' rating of 30C.

There is no standard way of testing cells, and no overall concensus over what an 'acceptable' voltage drop is.

This is why some cells have a 40C discharge rating, yet seem to be outdone by cells that have a 30 or 35C discharge rating. One cell manufacturer is probably being a little optomistic, and the other perhaps a little conservative.

This is why I maintain that manufacturers of Flight cells (Flightpower, Thunderpower, Hyperion etc) produce more accurate ratings than those in the car fraternity (LRP/Nosram, etc).

Also ratings like '40C' are a little too round. I think 38.5C is probably more accurate for some, and there is some over optomistic rounding going on.

Well, that was long.

Oh, on topic again, the GM lipos seem very good, and probably better than the LRP/Nosram 40C batteries. They just seem to have more punch.