Where to buy protected Li-ion battery in NZ?

[Beddhist]

Hi,

I'm after a battery similar to this one: http://cvpusa.com/airwire_battery.php

So far, I have not found one that doesn't come with a balance lead. It needs to be installed permanently and charged in the loco, so a balance lead is out and protection circuit is a must. I would prefer LiFePO4, but will settle for a Li-ion.

Thanks.

 

[gregh]

Well, if you can't find what you want, consider LiPo (unprotected)

Then get one of these to give undervoltage warning.
http://www.hobbyking.com/hobbyking/store/__13276__Turnigy_8482_Voltage_Monitor_3S_8S_.html

and you'll need a LiPo charger.

I use LiPo permanently in my locos. (sometimes with no undervoltage protection)
You'll just have to plug the undervoltage thing into the balance plug and connect the charger to the battery + and -ive.

 

[Beddhist]

Thanks Greg,

I have two LiPo batteries from Hobbyking and I have two such monitors. They will go into my small locos, where I can remove the batteries easily.

I have read that if I don't balance charge them from time to time then there is the danger of fire. In my big loco it has to be installed permanently, with only switch and charge plug accessible from the outside.

Cordless Renovations in the US have a variety of suitable batteries. Not sure yet whether they will ship to NZ.

I'm also not sure whether protection circuits will balance the cells, or perhaps some do and some don't.

Ideally, a LiFePO4 could be used. Then the danger is reduced. The selection there is much smaller.

 

[gregh]

Thanks Greg,

I have two LiPo batteries from Hobbyking and I have two such monitors. They will go into my small locos, where I can remove the batteries easily.

I have read that if I don't balance charge them from time to time then there is the danger of fire. In my big loco it has to be installed permanently, with only switch and charge plug accessible from the outside.

I don't balance charge my LiPo. I only charge at 300mA (2200-3000 mAh battery). My oldest LiPo battery is 5 years and whenever I check the balance (every year or so) , cells are all the same.
My Conclusion - don't need to balance charge if don't take a load more than say 1C and charge at say C/8.

 

[Beddhist]

That's very interesting. Thank you again.

 

[The Tinker]

I brought a charger with balance unit built in works well. I have also bought battery and balance unit from Crest in USA. they will ship batteries no problem it has a balance unit as part of it really neat unit and not to expensive

 

[Beddhist]

I've got a balancer charger, too. I just can't see myself making a hole in the loco's body big enough to pass the plug through. :-\

 

[The Tinker]

open smoke box door to access or behind grill if diesel

 

[Beddhist]

Having taken on board Greg's advice I have just placed an order for a 4S LiFePO4 battery on special for $25 plus post. It will feature in due course in my Airwire conversion log.

 

[Cliff George]

This seems to be similar to what you want:

http://cpc.farnell.com/ansmann/2447-3035/battery-pack-li-ion-4s2p-14-8v/dp/BT06049

I don't know if there is a NZ supplier.