Battery packs in races

[NPedeInsanity]

Hey guys. I'm new to electric, and I'm just wondering how you guys alternate packs during races. Do you have a practice pack you use before the races start, and then a pack you use for the heats? I'm not sure how many packs I should have if I'm going to be racing. Any help would definetly be appreciated, thanks!

[Demon-TC3]

1 pack for practive and 3 packs for heats...

At the moment i nonly have 3 packs so i use my "final" pack for a few laps of practice, then after my second race i put it on charge for the final (assuming we have 2 heats and a final).

I cahrge em all at home at 5Amps, then top em up at 7 before the race.:

Pack 1 - practive few laps
Pack 3 - Top up and first heat
Pack 2 - Top up ready for second heat
Pack 1 - as soon as pack 2 is done, charge up for final.

Its not ideal so i would find out how many heats (or races alltogether) you do at your track and add one for practice...

[crazy4wdracer]

If you are going to race you are going to want to have 3-4 packs to run
I have 2 for practice and 2 for heats

[nicholcgn]

When I run NIMH I have a min of 3 packs.

Practice A
Practice B
Practice A
Qual C
Qual B
Main C

Each pack gets run 2 times. The Best pack is for the mains. Always seems packs run the best second time.

[Demon-TC3]

yea if your running on a weekly basis NIMH needone cycle before they can give 100%

[cubbieman]

i was on a track that's about 3-400 feet running 3 laps and got about 2 races out of each pack. i have 7 packs(got a combo with one and tower had a quantity discount for 3 so i said what the hell) but that's obviously more than you'll need

[Ghostface Buggy]

3 NIMH's or 1 - 2 lipos. I bought 2 Orion 4800 lipos this month and I'm very happy with them. I'll never buy another NIMH pack again!

[GSMnow]

I always like to have a pack for practice and a pack for each heat. We run 2 qualifiers and a single main so that would be 4 good packs for a race day. Some people re-use a pack but it is hard on the batteries and a little risky. If I am early to the track, I may use my second qualifier pack for some full power practice for gearing setup. It should have time to top off again before I need it. I bring 2 chargers as well. I am not a believer in super high charge rates. The tiny voltage advantage some claim does not offset the greatly reduced life of the packs. I charge my IB4200's at just 3.6 amps, so it take 90 minutes for a full charge. But if I run 3 minutes of practice, it only takes 30 miniutes to top it off again. After the race I do discharge them all to 1 volt per cell and then charge them at 3.6 amps for the next race. Don't store NiMh batteries dead like NiCd. That will shorten their life as well. I need 2 more of the IB4200. I am currently using an RC2400 pack for the first qualifier, but it seriously slows at the end of 5 minutes. The IB's are faster after the 5 minutes than the RC2400's at the start.

I want to go LiPo but my local track still does not allow them for big races yet. I think they might for club events, I will have to ask again. For the JBRL race, they had the No LiPo sign out.

The Dynamite DC Vision Peak Ultra charger will do NiCd / NiMh up to 8 cells and LiPo up to 3S. I really like this charger. The only thing it does not do that I wish it did, is discharge.

Gary M.

[highroller]

Some tracks run a total of 4 races, 3 qualifiers and the main so that's 4 packs. It kinda depends on type of racing, or whether it's a weekly race or big event. Generally practice packs are older packs that aren't raced or at least one pretty good pack to get a good run in - that's close to race conditions.
Using NIMH kinda reduces having to have a bunch of packs, if you have roughly 2 hours between discharging and charging they can be used twice on race day. Practice then ran in qualifing heats and main - you may want to have 1-2 extra just in case a pack does have time to cool properly.
Now at big events (oval) I take roughly 10-16 packs, day 1 is practice for setup, day 2 is to get car up to speed or making fine chassis or tire changes. Plus with the CE35GFX I can cycle packs to see which of the packs might be better for racing - these too may get a practice run put in them so they are up to par come race day.