What causes 3000's to suddenly loose punch????
 

I recently lost 3 Fantom 3000NiMH packs to this... run time was fine but the totally lost all punch and acceleration... They had been sitting about 18 days over chirstmas, stored properly following all the advice I've read on the various sites and forums... but when I pulled them out to cycle them they were basically dead

All 3 were only about 12 months old but not heavily used... cycling them doesn't improve them... I am resigned to the fact that I am up for new batteries but I want to know what happened to them... I usually cycle them about every 14 days if I am not using them so I can't see an extra 4 days doing this:confused: :confused: :confused:

Is there anyway of rescuing them?:weird:

12 months seems to be about as long as anyone can get from a set of NiMH's - my HV's are now voltage-free but fine for run time (got about 10-11 good months out of them) - my old 3000H's died after about 6 months.

The cells perform worse in cold weather though.

My 3000H pack died after about 9 months. ( guessing ) Punch fell off well before that, but then it no-longer made run time. :lol:

My 3000HV pack that I bought last year finally fell off a couple months ago. I even had it re-matched along with a couple newer packs I had, and voltage had droped from 1.145 ( Orion Lavco matcher ) to about 1.108 ( CE matcher ). I knew it was bad, but I didnt know it was that bad.

You can try Zapping them....should give you a little voltage back in the cells. Sacrifice a bit of runtime....

I have had no problems leaving NiMH sit for 2-3 weeks.

I usually dump them at 20 amps with a 5.40 cut off. If you dump them at a lesser amperage then you risk ruining them. Very long term storage I don't know. Not yet anyway, I do want to do some testing in that area.

If NiMHs are taken care of they should last a long time and numbers should remain fairly consistant. My 3000HVs I have had for over a year and their numbers have still been very close to their factory specs. I have bought newer ones since then but still keep the HVs in my race box. I think it also helps to have a good charger where you can change the voltage cutoff. Like I use the Millenium. Older chargers have higher cutoffs and with the NiMH you overheat and ruin the electrodes in the cell.

My origional 3000s (1st gen) all went to junk. They were very fragile cells and it was pretty disgusting how the voltage dropped amd resistance increased. I dead shorted one of them for 10 months. Needless to say it came back to life. When doing this make sure you use a tray before jumping them pos to neg. You will loose a lot of runtime, decrease resistance and increase voltage. The longerm effects of this I don't really know the shortterm is packs that were not even worth practicing with can come back for practice.

I have:
2200s
2400s
3000s
3000HV
panasonic 3000 ultras
GP3300s

out of all of them the origional 3000s have been most fragile and would be the only ones I would expect to go bad.

Coop

As the cell ages and gets repeated charges it builds up more internal resistance. If your cells are peaking above 9.6 then odds are you will feel a loss of punch. New cells tend to peak around 9 - 9.1. My HV's started in the 9.2's and now peak around 9.5 (getting close to the end). My new GP3300's peak at 9.0 and have stayed there over the last 10 charges.

I never cycle or tray any of the NiMH's and I never repeak at the same charge rate it was charged (lower the cutoff to .02) ... and I discharge to 5.4v at 20A. The key to keeping the cells at a low IR for a long time is not to overcharge the cells. Your cutoff for the cells will change as the environment changes. So watch the voltage on your charger as it reaches the end and stop the cells manually once you see it start dropping back beyond what you set for cutoff. Then change the cutoff to a lower number and it should cutoff itself next charge.


Just my 2 cents.

Hi guys. Greetings from Malta.

I must say that I agree on the short lifespan of most of todays cells.

The original RC3000 and the original blue Panasonic 3000 had a very short life at good power.

The HV3000 was better when new but you are lucky to get a season's racing out of them. The same goes with the Panasonic SMH and UMH.

I have run and tested them all. We race every fortnight (2 weeks) and I keep my race batteries for the racing only, using last years packs for practice. My son uses the UHM for modified because they give a bit more time, and I use the HV for stock because they have a bit more power, and time just isn't a problem in stock.

I have tested them on my Protrak regularly and yes, I too find that they loose out on everything rapidly. They are all superb when they are new, but I reckon they loose a fraction with every cycle. My Panasonic UMH used to give over 500 seconds. 4 months down the road they are already down to 440.

I remember the days of the 1700 Nicads which used to get better with each cycle. These get worse.

So yes, you will get a 9 month season out of a pack if you're lucky. I think we just have to accept that.

I don't know anything about 3300s. They are still illegal in our country so I haven't tried any, but I would be interested to hear from people that have.

Regards

Joe from sunny Malta.

Flat packs
 

Guys;

I bought a 3000HV pack with the recommendation that they would have better punch than my 2400 NiCd's, but this has not been the case. I use the 3000's for practice and the 2400's for racing. I also have GP3300's in my Nitro Starter Box with an E-Maxx 19T Mod. :D

You can try to save them by basic cycling on them.

Heres what I do:

Charge at 5.0v discharge at 20 amps to 5.4 v
Then leveae them there for a day and put on the tray before chagring up agian. I put them on till them little light is almost dead on each cell. then chagre right after you have undone each cell on the tray.
Then repeat this for about 3 days or 4 days and then leave your packs at 5.4 if you race weekly on every other week. ANylonger put a little chage in each. So then when you are ready to chage all your packs will be at 5.4 v so you can just put um on the tray and chage:D