Tamiya Batteries

[Shodog]

Inside my sand scorcher was a brandnew tamiya battery. this is the one with the plastic shell. I'm sure that these probably won't be too good. I have a nice reedy quasar pro charger that might be able to rehabilitate the battery a bit. I can cycle up to three times in a row. What rates should I charge and discharge at? I was thinking of charging at 1.0 amp and discharging at 5. I don't wan to melt the cover.

Jim

[DJTheo]

Usually charge NiCd with a current equal to 2-2.5x of their capacity, so 2.4A-3A. Best way for those oldies though is to slow charge with 120 mA for 14 hours.

http://www.vintagetamiyarc.com/

[mr_lister999.]

Probably the best way but i just wack up the current and charge them at whatever i want. (usually about 5 amps) Got a couple of old batteries and they work fine. I use the revers pulse charge on my Novak charger to condition them. I am not very patient when it comes to waiting for a pack to charge.

[Spike]

I have no doubt that this has been discussed before but..

I have a couple of original Tamiya packs that are totally knackered. I want to open them up and stuff some modern cells in there.

Has anyone managed to open up the plastic cases without wrecking them? If so how

Thanks

[Shodog]

We hashed this out a while ago. The concensus was no way Jose. they are hermetically sealed.

[RETRO R/C]

Hello Jimmy,

Batteries and motors are some of my favorite topics !!

For the old 1200's inside that plastic shell - I would recommend the following: a nice long slow charge - with a nice discharge on a indicator light from a real car - should take a few hours to discharge.

FIRST F A S T CHARGE - 3 amps MAX - Not sure if the Quasar had neg pulse ability - if not - just charge till slightly warm. DISCHARGE at at aoud 8 to 10 amps...again checking the temp.

Second Charge - 4 amps - checking temp all the time. - discharge at 10 - 12 amps.

Third charge - 5 to 6 amps - CHECK the temp - discharge at 15 amps.

The reasoning behind the ramping of the discharge and charge rates is to get the battery behaving like it will in the car......It is not unusual for batteries to have over 30 amps spikes under accelaration etc.......

Genrally I would then stick at a charge rate of around 4 to 5 amps - as these old cells are tough - and like to be treated that way...just be sure to bring them in slowly - and always discharge them fully after every run.........they are the complete opposite of the current crop of NIMH 3000 cells.

Happy to go alot deeper on this topic of you like.

Cheers mate

Darryn

Visit my Web Page !!

[Shodog]

Thanks everyone for the info. The Reedy Quasar is their top line charger that has all the bells and whistles. It is programable so I can manipulate all the charge cycles

Jim

[DJTheo]

Darryn, are there dischargers that can go so high, or do you use motors or resistor?

You are right about the ramp method, but I think the last row numbers are a bit too high for those old 1200s, since they mean charging in 15mins and discharging in 7 and even for new cells it isnt reccomended to use much more then the 2-2.5x capacity charge current, as it brings alot of heat and short life.

Btw, don't discharge them lower than approx. 5V.

Cheers

http://www.vintagetamiyarc.com/

[RETRO R/C]

Hey - no probs Jimmy,

The idea of the first few charges is to "set" the cells into a pattern.....yes - heat is a problem - however to wake them up - they will need this........as stated - you need to keep a close eye on the heat.

I remember (in fact I did it just last week!!) - hotshots/optima's etc running with the wheels off the deck - drawing 4 to 5 amps - NO LOAD !

Now these cars were alot lighter / efficient than the RB's - so it has to be said that a RB running on grass/dirt would have to regularly reaching at least 7 to 10 amps at load......naturally accelerating from rest would probably go more into the 20 amp range ......... doing "circle work" would be even higher !

Sanyo "SC's" and SCF's" are still the toughest batteries aver made - they are practically bomb proof. I used the above method with some dead "hump" packs that I have sitting around.....it took longer to get them to last a reasonable ampount of time - because they had been used previously - however now I get aroubnd 7 to 10 minutes out of them in my Wild Willy one - compared to 3 or 4 minutes when I first charged them.

The above method works well - and should work even better with new cells - as they have no memory - however it really does depend on how they were stored etc etc.....sometimes dead is dead

Cheers

Darryn

Visit my Web Page !!

[RETRO R/C]

Oh yeah - I always store these "oldy mouldy" batteries with a 5 Watt - 30 ohm resistor accross them........take the resistor off about an hour before I charge them - this allows the cells to equalise.

I use a discharger to to take the juice out of my cells - or a row of light globes....even better - strap em into a car - and have some fun !!

cheers

Darryn

Visit my Web Page !!

Edited by - darryn1 on 20 Sep 2002 19:04:39