# Help, With batteries



## idnthvn (Jan 22, 2012)

Hi, Ive been racing for years. but never got serious enough to worry about my batterys. i always enjoyed just running n having fun. but ive been wanting more n more competition n run better with the big guys. 
Issue is, i buy pack batteries n they are not matched. and the batteries i do have i can never seem to keep more then a year. always seems to me i lose a cell in the packs n have a run time of like 2 minutes before it starts to dump but holds there for the remander of the race. 
So my question and hope to have alot of input from you guys is
What am i doing wrong to continuely burn up batteries over the coarse of the summer. 
and 
What do i need to look for when buying a charger to match the cells for my next packs???
Thank you all for your help in advance


www.riversideraceway.webs.com


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## nutz4rc (Oct 14, 2003)

Sorry see below.


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## nutz4rc (Oct 14, 2003)

Need some more info before offering any suggestions. 

What type of batteries? 

What MAH?

How many cells in pack?

How do you charge?

How do you maintain?

What type of racing? (Video is Oval so I assume that is what you are talking about)


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## idnthvn (Jan 22, 2012)

TY for the reply, and yes sry for not enough info


NIMH batteries.

6 cells (7,2V)

i usually leave them alone from week to week. But ive tried Fully charged, Half charged and drained to 5.4V or when the lights dim out on my 11 lightbulb discharger (about 20-25 amp draw. which leaves them to about 6.0 to 6.8 Volts when resting)
I Charge all batterys at 5 Amps. Yes even my 2400Mah as they do get warm but not Hott where i cant touch them. Also, I race oval.
I also drain them completly down at least once a week throughout raceing season. Like before i charge them on race day> Usually Cycled once. n then they are ran hard on race day n then put away. 
I need more knowledge on how to properly maintain/store, and how they should be ran.
Bc ive had someone tell me and has had no issues with after draining each cell down to .9 or lower he then solders a wire on the pack from neg to pos. so the battery stays at 0.0v for the week, then on race day unsolders them, lets the voltage rise n then charge them n cycle once before racing. > just im at lost due to cells consistantly dropping or cant keep them matched.
Now my Charger was at MV peak detection at 7Mv and i recently upped it to 8mv to get a better charge on batteries as its been working nice.


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## ta_man (Apr 10, 2005)

The biggest issue I see from what you have written is mentioning use of a bulb discharger to drain the packs and not a cell equalizer like a Novak Smart Tray. If you don't use an equalizer, it is very easy to reverse polarity on one or more cells in that pack and ruin them. You can pick up Novak Smart trays on eBay for sometimes $5 plus shipping.

This is, of course, based on using side-by-side packs. There is really no effective way to equalize stick packs.

The other "of course" is that this is all ancient history. LiPos have pretty much taken over from NiMH packs for racing.


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## idnthvn (Jan 22, 2012)

Yes i wish we could all go to Li-po's but we have much more kids who dont always pay attention and being lipos catch n are easier to ruin he likes the NIMH, but i dont think ive had them in reverse polarity, or i would assume so as the batteries have never been an issue untill i have them set for the 6 months we dont use them. 
And ive done a little playing, Ive been cycling them and put a volt meter on each cell as they are being drained and notice that 1 or 2 cells are .1 or .2 difference in them from the others. 

should i swap them out?




ta_man said:


> The biggest issue I see from what you have written is mentioning use of a bulb discharger to drain the packs and not a cell equalizer like a Novak Smart Tray. If you don't use an equalizer, it is very easy to reverse polarity on one or more cells in that pack and ruin them. You can pick up Novak Smart trays on eBay for sometimes $5 plus shipping.
> 
> This is, of course, based on using side-by-side packs. There is really no effective way to equalize stick packs.
> 
> The other "of course" is that this is all ancient history. LiPos have pretty much taken over from NiMH packs for racing.


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## bojo (May 6, 2002)

Bring them down to 0 volts Then put a wire on pos and neg leave them till you use them. Just charge back up. Getting a smart tray or anything that will bring them down to 0. Put wire on them still in the tray so thy are still 0 volts.


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## Lucky Lance (Dec 29, 2004)

*Lipo's*

If your'e kids are just yard bashing, why do you need MATCHED cells?
If they are racing in a club, NO 4 minute heat is even going to come close to draining a lipo.
If they use lipo's for yard bashing, (THAT CAN BE A PROBLEM). Lipo's should NEVER be DRAINED to certain levels or there is a fire hazard. 
So, I guess your'e answer should depend on how you've read this answer. 
Yard bashing = NON-MATCHED packs would be OH SO MUCH CHEAPER, and lipo's would be a NO-NO. 
Club racing = even MATCHED batteries are ANTIQUES in MOST CLUBS and with lipo's you can run the same pack in the car/truck all day if you want, they don't get to HOT, they can be RECHARGED multiple times a day.
I would suggest that you check with you club (for legality), or even for yard bashing, that you go to HOBBY KING site and you will find lipo's for under $15.00 in some cases. Don't know about regular NIMI prices there, never needed to check on them. Hope this helps...:wave::thumbsup:


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## idnthvn (Jan 22, 2012)

Thank you lucky, 
but lipo's are a no-go in the racing league we run due to the majority of kids in this.
Matching cells for me is almost a must. I ruined the batterys due to improper discharge. so i am now going to sort through n get the bad ones out. 

But its not so much matching, its more on making sure i dont lose a cell each year to have a slow car the next. I appreciate everyones help. 

I have now gotten the smart tray, and the turbo 35BL to start the battery care. 
I will be getting a bulb discharger to stop at 5.4V so that they safely are discharged soon. 
Thank you all. 
and i hope more noobs into the sport will read this and get valueable learning from it 


Thanks again 


Josh


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## Lucky Lance (Dec 29, 2004)

*Your call*

But I see no reason why kids can't run lipo, if your'e worried about speed differences between nimi and lipo --- gear them down, or turn down the timing, (if you use brushless). Once again a lipo can be put in a car and left all day and be recharged over and over. 1 cell lipos would be plenty for oval. T - 4 or REVO type Trucks would need 2 cell and that's where it could get hairy. But if your'e using MATCHED cells in trucks you have to much power for kids anyway. run BRL rules for oval...1 cell 4000 SMC packs...17.5 brushless....speedo set on BLINKY...World GT tires...and if you want to slow the kids down more, set the timing at zero too....You WILL not lose any cells as long as your'e not letting the kids practice for 20 minutes non stop. Like I said before a 1 cell 3.7 4000 SMC battery can be installed and ran ALL DAY without ever taking it out of the car...I won't bug you anymore but you could save a lot of GREEN going the lipo way...


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## idnthvn (Jan 22, 2012)

I agree. But my track dont allow lipos in the classrs i run. In the future i see the classs changing.and we akso run 5 minutes.


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## NCFRC (Aug 4, 2005)

bojo said:


> Bring them down to 0 volts Then put a wire on pos and neg leave them till you use them. Just charge back up. Getting a smart tray or anything that will bring them down to 0. Put wire on them still in the tray so thy are still 0 volts.


+1 ,, This worked great on the last gen. of nimh cells :thumbsup:


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