Looking after Nimh stick packs - seeking advice

[Nige]

Chaps,

I've got five Team Orion 4500mah Nimh stick packs http://www.modelsport.co.uk/index.php?product_id=29664 but have noticed that when charging they don't go to full capacity. I did assume it was because I hadn't used all the power so they just needed topping up when I recharged them, but now I am not too sure. So I've gone and bought a Nosram Gravity Stick Pack discharger http://www.nosram.com/en/products/chargers/discharger-equipment/produkt/nosram-gravity-stickpack-discharger/details/ And I have an Ansmann XBase Deluxe charger http://www.fusionhobbies.com/Ansmann-Racing-xBase-Deluxe-Charger-p/ar151100001.htm

So I'd appreciate some advice on what is the best way to maintain my batteries. Please no signing the praises of Lipo, I'll be staying with Nimh for the time being thanks.

After racing should I just leave my batteries // charge them to xx mah // discharge + charge them to xx mah? And then the day before racing just charge them // discharge, then charge..........or something else?

Cheers fellas,
Nige

[digitrc]

General rule with NiMH's is to not discharge them fully (no less than 0.9V per cell), and store them with a partial charge (say, 1000mAh).

Charge on the day if you can, if not the night before is fine. Re-peaking on the day can be a shade risky because you might overcharge the cells.

NiMH's biggest problem (especially with the more race oriented cells, although Orion's rocket packs aren't usually race cells) is self discharge. It can kill the cells if stored unused for long periods (months), and even during short term storage (weeks) between race meetings it can put the cells out of balance. This is why equalisers were such a common accessory in the NiMH days.

There is only one equaliser that I know of for stick packs, and that is/was made by Much-More. It required cutting holes in the heatshrink in the side of the pack.

An alternative way of equalising is to put the cells on a trickle charge at 0.1C for 12-14hrs, this will top up all the cells to an equal level.

[Chequered Flag Racing]

Originally Posted by digitrc

There is only one equaliser that I know of for stick packs, and that is/was made by Much-More. It required cutting holes in the heatshrink in the side of the pack.

this one



and a video by RC Lazy

[Chequered Flag Racing]

[QUOTE=Chequered Flag Racing;461387]this one



and a video by rclazy

[Chequered Flag Racing]

look at the graphs on the Pro-Trak site http://pro-trak.co.uk/intensiv.htm

talks about Ni-Cd's but it's the same idea for Ni-Mh's

the MuchMore item is doing the same as the Pro-Trak ICS

[ianhaye]

always found best to repeak right before the race so bats are peaked up nicely and warm ready to go, nimhs work better when warm ;-) but not to hot lol

[Nige]

Cheers for your help guys.

Yet another great video from RCLazy, looks like I'll go and buy one of those Much-More Equalisers! Much better than the Nosram discharger.

[JonMack]

Originally Posted by Nige

Cheers for your help guys.

Yet another great video from RCLazy, looks like I'll go and buy one of those Much-More Equalisers! Much better than the Nosram discharger.

There's a Pro Trak one on ebay,

http://cgi.ebay.co.uk/Pro-Trak-Inten...item3cb4ff97d5

[digitrc]

Originally Posted by JonMack

There's a Pro Trak one on ebay,

http://cgi.ebay.co.uk/Pro-Trak-Inten...item3cb4ff97d5

Two reasons why this is isn't suitable...

1. It discharges to zero volts which is a no-no for NiMH

2. It won't equalise a stick pack.

[Chequered Flag Racing]

Originally Posted by Nige

looks like I'll go and buy one of those Much-More Equalisers! Much better than the Nosram discharger.

MuchMore better than the Nosram