# Nicad Secrets / Veteran Racers



## NCFRC (Aug 4, 2005)

For those of us who have been around this sport for 15-20 years and can remember back that far , what was the hot set up for charging and maintaining Sanyo SCR red cells.
We're running them in Spec this year "1900's " and was wondering how to extract the max volts and lower IR , we didn't even know what Ir was back then.
High charge rates ??
Flex charging ?? and at what setting
Resistor overnight , maybe a week ?

Any input greatly appreciated , runtime not a concern

R.S.


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## ta_man (Apr 10, 2005)

I am not specifically using the Sanyo cells (or maybe I am and don't know it - the individual cells are not labelled) but one of the classes that I run requires a 1500 MAhr battery under $25 retail. The ones that I ended up with are the Piranha packs. I've been running this class for 4 years now and have gone through many packs. So far this year I have had really good results with a new (for me) discharge technique.

After the race I let them cool (I use a fan to speed cooling) then dump them at 20A (there isn't much left) down to 5.4V (6-cell pack). Then I discharge them at decreasing rates down to 6V (yes, 6V, or *1V per cell*). I start off at 3A, then 1.5A, eventually going down to *.1A*. By ending up with a very low discharge rate, I feel I am removing as much entergy as possible and the 6V cutoff (hopefully) prevents me from reversing any cells. I have never put a resistor or battery bug on this year's packs and they are performing great so far.

The whole discharge process takes a while, but I race other classes too, so that is not an issue for me. Not all chargers/dischargers will go down to a .1A discharge rate. I use a Triton charger to both charge and discharge these packs. The Triton is the only charger I have that has never false peaked on these things.


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## hankster (Jan 1, 1998)

This is what we did for the 1200/1400 Red SCR Sanyo cells. Discharge down to 0 volts and then deadshort the packs. Charging can be done at 8 amps, even have done up to 10+ amps in cases where we needed a packed charged quick and found no adverse effects.

Disclaimer: Not sure if the present day cells will respond the same as they did to those cells made 15+ years ago.


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## NCFRC (Aug 4, 2005)

Thanks for your replys and yes some of todays nicad cells are hybrid , sort of and do behave alot different than the old ones.
So far these Sanyo's seem to be much the same as the old 1400 red SCR's and respond well to High rates and a 30 ohm resistor.

Only time will tell

R.S.


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## NCFRC (Aug 4, 2005)

Probably a 0.0 tray would be better

R.S.


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## Kenwood (Oct 18, 2004)

The SPEC packs ENJOY the turboflex option on the GFX.. Or if you have an old school tekin or victor burp charger..>>the kind where they chrage then Discharge for a second then charge... it helps break up the crystilization in the cells.. I still use a victor burp charger for my spec packs.. I took 1 pack that belonged to someone else and used the charger on it...He picked up like 2 laps.. When I looked at his regimine I could see why the cells had bad memory built into them..


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## DJ1978 (Sep 26, 2001)

Kenwood said:


> When I looked at his regimine I could see why the cells had bad memory built into them..



That has been the key that I have always found with Nicads... They like the same charge and discharge routine. What ever it is... as long as you continue to use the same routine on them. Full discharge and equalizing is the key.


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## NCFRC (Aug 4, 2005)

Thanks , I have been cycling on a GFX and it seems the lower the flex setting , I'm on # 2 , the better the Ir and longer run time , but these cells are new also , so maybe they don't need heavy flexing ??

R.S.


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## Kenwood (Oct 18, 2004)

The flex will help them NOT build memory over time.. Its not going to take a new pack and make it 50 times better... But what you find is guys who have bad habbits of not fully discharging packs the flex brings those cells back to life..


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## Kenwood (Oct 18, 2004)

FWIW I dont know what the NEW cells are like.. But old nicads I charged HIGH amperage.. Like Charge 10 peak 12.. for stock racing.. Back in the 6 cell days..


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## NCFRC (Aug 4, 2005)

I've been hitting them with 8 and peaking at 9 on a 4 cell pack and the runtime is increasing and Ir is going down.


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## NCFRC (Aug 4, 2005)

I've been doing some testing and experimenting with several packs and this is what I've found . Like any battery question , even people who raced nicads all disagree.
Charge at 8-9 amps and discharge at 15-20 amps.
Forget ! the 30 ohm resistor days, the IR is terrible that way , suspecting
that some cells have seen neg voltage.
Leave in a 0.0 tray for overnight or 24 hours , I've even left them in a 0-30
for that long , it really doesn't matter once they hit zero , but they have to
be discharged individully.
After removing from tray let the cells rebound for at least a few hours , again maybe overnight and a good pack will have 3-4 volts in it and recharge.
Most of my Sanyo SCR cells are improving as far as runtime and the IR is gradually going down .
The runtime thing is different to get used to as every IB cell we race in a different class looses runtime from the first charge on.

Again ----Only my opinion and the new NICAD cells " example - trinity speed spec packs" are a hybrid nicad cell and like to be treated more like a nimh.

As with any battery , you have to experiment and see what works for you.

Oh I did forget , when charging the SCR's , put your GFX on #2 setting for flex or on a Tekin use PF-1 , too much flex on a fairly new cell raises the IR quite a bit.

R.S.


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## dave w 1 (Apr 28, 2005)

OKAY HERE YA GO THIS IS FROM THE OLD WHIPPORWILL DAYS WE CHARGED AT 6 TO 8 AMPS AFTER A RUN DUMPED THEM HARD BACK THEn 25 AMPS TAKE THE CELLS TO 0 THEN DEAD SHORT WE THEN LET THEM SIT UNTILL NIGHT BEFORE RACE . then we cycled the packs at 6 amp charge 25 amp discharge the ir will be very high dont worry they will run great next run then just repeat over let me know if i can help in any way


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## NCFRC (Aug 4, 2005)

Kenwood said:


> FWIW I dont know what the NEW cells are like.. But old nicads I charged HIGH amperage.. Like Charge 10 peak 12.. for stock racing.. Back in the 6 cell days..



The new generation of hybrid nicads won't take it , their much more like nimh's. example - trinity speed spec cells.

The Sanyo red scr's seem to be of the original chemistry and construction and don't mind a bit. It's been a long time since I've seen cells get better the more you cycle them.

Thanks for your feedback 

R.S.


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## NCFRC (Aug 4, 2005)

After leaving in a 0.0 tray for a few hours or overnight , short each cell with a wire and leave till next weeks race. Don't dead-short the pack! Only each individual cell.

Both NASA and the Military use this procedure on nicad cells.


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