Zerodefect

New to onroad, I went from nicad to lipo. Was out of rc for the time offroad was using NIHM.

Do these have a memory like NICAD and need discharging before charge, or can you just "fill 'um up" like LiPos.

Can you recharge them throughout the day. I'd like to get into 4 cell pan car, and unfortunatly Lipo rules aren't here yet.

Trips

iTrader: (16)

NIMH cells don't have the same memory effects of nicad, but you do want to discharge them before charging. I discharge the pack as a pack at 30 amps down to 3.6v, then put the pack in a tray that slow discharges each cell too .9v before charging. You can run the same pack more than once a day, but on a typical club race day I find there's not enough time to properly dfischarge before charging for the next run, so two packs would be ideal... run one in round 1 and round 3, the other for round 2 and the main.

Between race days you want them stored with some charge in them, I hit each pack with 6 amps for fifteen minutes when I get home from the track and leave them til the next weekend.

Zerodefect

Thanks. Looks like I'll need a discharger tray and another battery added to my onroad race list.

I wish we could just run single cell lipo 17.5. Might just wait it out.

SpraydbySprague

iTrader: (64)

As far as discharge trays go. I own 2 of these.

http://www.muchmoreusa.com/dischargers/mmrp1020.html

It's not cheap at 200 a pop, but they discharge at 30 amps pulse and 5 amps linear. The 30 amp pulse keeps the cells from gettin hot. The 5 amp linear will ensure the cells are fully equalized.

The biggest reason to equalize before charging is the extreme difference in the rate of self discharge in a pack. In the best of matched packs the difference in rate of self discharge can be as much as 50% between any given cells.

I equalize my packs on race day before charging. First at the 30 amp pulse, then at the 5 amp linear. Cells never get above 90 degrees. I let them sit for a few mins then charge the cells. Making sure they peak off about 10 mins before I go to race. After the race I simply put them away with whatever charge is left in them until next week. At 4600 mah capacity running 17.5 brushless, the cells still have plenty of charge left in them for a week to week storage.

Zerodefect

Got to love the MMR stuff. I got a lipo rx pack from them,and it has a shutoff built in! I'll check out thier tray. $200 is alot! Thats more than my charger!

Nihm is kind of a bummer if we are about to switch from NIHM to lipo.

Thanks for the help.
Now I have to choose between simple xray or complicated serpent or crc cars....

SpraydbySprague

iTrader: (64)

I've owned several different discharge trays. The Muchmore trays are the best. No need to babysit them. Just turn them on and let them do their thing. What kinda charger do you have?

Parnelli

iTrader: (18)

What is the normal voltage for these packs when fully charged. Mine show 6.8 volts, is this right? Thanks.

SpraydbySprague

iTrader: (64)

4, 5, or 6 cell pack? What's a Washburn monkey anyway?

Zerodefect

I have a Hyperion 6010 ac/dc charger and the Hyperion model thats one step higher than that as well (250watt if I remember right). I'm set for chargers so I don't have to worry bout that.

Are the Trinity matched team packs still good. Looks like I'll need two of them.

Parnelli

iTrader: (18)

SS they are 4 cell packs for VTA. A Washburn monkey is a mythical Autox creature from Wisconsin, kinda like a Jersey devil.

SpraydbySprague

iTrader: (64)

Myself along with many other fellow drivers, are pleased with the EnerG4600 cells. There are several companies who match them. SMC, ProMatch, OHP(Ohio Hobby Plus? I think). I'm not sure if Trinity uses the EnerG cells.

Never seen a 4 cell pack hit 6.8. What are your charger settings; amp rate, cut off settings, temp? Do the cells come off the charger at an even temp? Most of my packs get to 6.5 volts, this is charging at a 7 amp charge rate.

I like the comparative refrence to my home state's own mythical mascot.

Parnelli

iTrader: (18)

S by S, I have a Vision Peak 2 charger I run at 2 amp rate. Yes I need to upgrade. I no longer discharge my nimh packs since I cannot control the cutoff point (old rack of 1157 auto bulbs). Last night I changed the connector (removed the Tamiya to Deans adapter) and recharged. Today my 4 cell packs after charging and cool down read 7.2 volts. They are 4000MAH packs from CBP.com. I thought they would peak out at about 5.6 volts. Thanks for your help.