My Batteries Keep Dying... Please Help

[boostinzx]

Hey guys/girls... I am new to the RC world and was loving it at first:)... untill I got duped into buying about 600.00 worth of equipment for my first car... lol... anyways... I am having a major problem with my batteries... When I first got the car my batteries would charge fine... They would take about 30 - 45 minutes to fully charge and you could run the car for about 20 minutes at full throttle the whole time before they would die out... Now everytime that I charge them they will only take like 10 minutes to charge on my Vision Peak Plus Peak Charger... Then when I put them in the car... they don't even have enough power to turn the wheels over hardly... and will only move the car around on the floor for less than 2 minutes... I tried buying a new battery and it did the same thing it only took like 10 minutes to charge and then was extremely weak... Is it my charger? I have only used the charger like 10-15 times...and ive had it for awhile so I can't take it back... What do you guys suggest that I try? Here are the specs of my car if that matters

Team Associated TC3 with Rally Conversion (200mm) kit
MVP Engine (i dont know the turn off hand)
Futaba Servos and Controller
Novak Rooster ESC
Venom Racing Batteries
Vision Peak Plus Charger

Sorry that I don't have very much knowledge here... I am trying though:)

Thanks in advance for any suggestions/help...

EDIT: Also the batteries were 3000mah NIMH batteries... the venom ones and the new one...

-Ian

[rocknbil]

I'm an old-schooler (manual charging/peaking) so I won't offer a solution but I'll seed it with a question I know is coming: what are you doing after a run, are you using any discharging methods or battery equalization?

First guess is that the charger's false peaking, welcome aboard and stay tuned for fellow auto-peakers. :D

[viper2002]

Yes most likely it is in your charger. Does it have any options for "peak threshold" or anything like that? Tell us how you have it set up.

[baileyk]

The batteries are false peaking. When the batteries peak they should be warm to the touch. If they are not warm, they false peaked. Simply start the charge again until they are warm to the touch. If the batteries were not properly taken care of, you could possibly have bad cells, but if a brand new pack only took 10 min, it definately false peaked.

Can you adjust the threshold on your charger? If this number is set to low, it could be causing false peaks.

Kraen

[boostinzx]

I cant really adjust anything on the charger besides 1 or 4 amps charging rate... I have always used the 4amp option... here is my charger...

http://www.dynamiterc.com/Products/Detail.aspx?ProductID=DYN4046

and I don't discharge the packs after runs or anything like that... I am just now reading up on that and learned that that is what I should do... but im still trying to figure out how I am going to do it:)

Also... If i hook the battery back up to the charger and try to charge it again, it will still only take a few minutes and it says its done... so I guess it keeps "false peaking" Also... I played with the R/C car there a bunch for a little while and then I kinda got out of it so the packs sat there for a while... they should have still had a little charge in them but they probably sat for 6 months or so without me doing anything to them... so are they fried..? The new pack that I bought I just noticed on the back that it says to not charge with a fast charger, so that is probably my problem there...
Is there any way I can check and see what the packs still have in them? and if they have bad cells in them or not... ?

Here are my batteries... I have used them probably 10-15 times each... and There was only 1 or 2 times that I didnt let them cool completely before charging them up again...

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXHUJ9&P=ML

thank you guys for your help... I really appreciate it...

right now im thinking I will probably need to buy a different charger that has more options for charging at different rates... and come up with some kind of discharger since i am using NiMH packs...

[boostinzx]

and here is my engine if it matters... i could tell it was it by the picture:)... Im at work so I don't have the car with me... tahts why i couldnt remember what it was...

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXZS59&P=7

[boostinzx]

should i purchase a discharger like this since i dont have the nicer type batteries... all i do is play with my rc car every now and then in a parkinglot... no big racing for me:)...

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXHUK1&P=7

[TimisTim]

Since your batteries are NIMH you dont have to discharge them all the time. I just do mine about once a month if I have just been bashing on them. If you are seriously racing then I would discharge before every recharge. Also when storing the batteries you should leave a charge in them, it goes like this....the longer you are going to store them the more of a charge you should leave in them. If you are going to be storing them for a month or more then I would suggest a 3/4 charge, if you are just going to be leaving them for a week or two I would suggest a few 100 or mabey a 1/4 charge. I think this has to do with the fact that the batteries will lose some charge naturally and should never be "dead shorted" (NIMH only).

This link will take you to a page that will answer most all of your questions. Even though they talk about the "gp3300" batteries it doesnt matter this is how any NIMH battery should be taken care of. http://www.promatchracing.com/faq.htm

[highroller]

There is no problem with either the charger but is contributed to how you are taking care of the battery packs. NiMh like Nicads need to be discharged of any remaining voltage after use, another problem that is leading to your problem is cells begin to discharge at different voltage levels. When the pack is charged after several cycles, by cells being at different voltage levels it leads to pack false peaking.

To eliminate most of the false peaking problems follow this routine to see if it helps. After use; discharge the pack with a string of lightbulbs close to the load it sees during use 5 bulbs (10amp) for bashing, 10 bulbs (20amp) for stock racing 15 bulbs (30amps) for oval racing. Store the packs with .90 volts per cell (5.40volts for 6cell, 3.60 volts for 4cell packs) when you are ready to charge the pack use a discharge resistor (Radio Shack 1ohm 10watt discharge resistor leave on until the resistor cools), pack equalizer, one single bulb (1157) attach it to pack to bring pack voltage to a lower level. By removing as much residual voltage from the cells and getting them as close as possible to the same voltage levels you will have a couple of benefits (provided the cells are in good condition) 1. you eliminate most if not all problems with false peaks 2. since cells are starting out being charged closer to the same levels they will reach the same levels when charged 3. they should be able to charge and run longer by cells being closer in voltage levels.
If you use the pack more than once, allow the pack to cool properly at room temperature before charging it. The GP and Sanyo NiMh are pretty durable and can be stored for up to 6 months inactive at .90 volts per cell - for racing use they may seem flat for a couple of cycles but Panasonics can only be stored 1-2 months with no use. Instead of cycling (charging and then discharging) packs as some suggest charge the pack up and run it in vehicle, once pack begins to be used more often any flatness should be gone. Even for racing use, if pack has sat awhile I use it in practice then discharge it, place in an equalizing tray and run it in one qualifing heat. The only time I cycle a pack is because of age, or it performs inconsistantly - then a GFX is used to get a more accurate reading of what the cells are like.