Battery Packs for Remote Control

I have been gifted an unused MacGregor Digimac VI remote control set dating from the 60s or 70s. The battery packs , 500mA NiCads in 3 packs of 4 are defunct and require replacement. I have tested the Digimac and it functions well on temporary 1.5V dry cells. My first thoughts are to replace the batteries with NiMH cells which will have a greater output and presumably will work for longer between charges.

My questions are, where shall I source the new batteries from? There are loads on EBay but they vary wildly in price although they all look the same. Anyone had any experience in buying them?

Secondly, the Digimac charger has no markings and is the type that cuts out when full charge is reached. Will this charger handle NiMH batteries say between 900mA and 2000mA?

Any advice appreciated.

Mick

Edit. It is for use on a steam powered boat

Edited By mick H on 28/06/2018 09:14:02

Mick

Have a look at www.strikalite.co.uk they build custom battery packs, friendly people good products

Mike

You should find what you require Here they give a good service and have a good range of batteries and components, I'm a satisfied customer. Mike.

+1 for Component Shop - excellent service!

You may find you need a different charger for NiMH.

Some information here:

http://www.greenbatteries.com/nimh-battery-charger-faq/

Mick

Original were 9.6v Transmitter pack and 4.8v receiver pack, as you say 3x4cell packs.

Best go for the largest ma rating you can get in the NiMh AA size cells and buy a charger to suit as I don't believe the Nicad charger is compatable with the new cells. (previous post says same)

Emgee

Edited By Emgee on 28/06/2018 11:22:51

NiMH batteries can be charged by a simple constant current charger, the same as NiCd batteries.

But if left on constant current charge, the NiMH battery will be damaged.

The NiMH type has a very characteristic "hump" in the voltage/time graph as it becomes fully charged.

When the battery is fully charged the cell voltage falls and the cell temperature rises.

A good NiMH charger detects this fall in voltage and cuts the charge.

JimB

Thank you for the information and recommendations gents. I am currently perusing their offerings. I didn't realise there was such a range of stuff out there.

Mick

Usual arrangement these days is to go for a Lithium Ion pack (LiFePO4)as the nominal voltage is close to the original.

Pack is removed for charging on a dedicated charger however this only needs to be done at a much longer time scale than the original.

Packs normally are 1500mAh capacity @9.9V and cost around $10.00 from HobbyKing.

Of course there is additional delivery charge involved and chargers are available from them in a wide variety of models makes and cost.

Biggest benefit is the pack can be fitted to some of the newer 2.4g radios when/if you upgrade.

A little research will show which way to go, plenty of info on rc forums.