Icom M31 Batteries

[JumbleDuck]

A couple of years ago I bought - from the For Sale forum - an Icom M31 handheld. The seller warned me that the battery was dud, so I bought a non-original NiMH battery from eBay. I bought that because the radio came with two chargers, for Li-ion and NiMH and while the Li-ion charger will charge an NiMH battery, the NiMH battery will not charge a Li-ion battery.

All was well, but on trying the radio this year I find that battery life from fully charged is around four minutes. This suggest to me that the battery is knackered. Before I shell out more cash ...

* Are pattern NiMH batteries occasionally dodgy like this or is it my own damn fault for leaving it discharged in the boat over winter?

* Can anyone recommend a battery supplier? Preferably NiMH so that I can still have two chargers.

 

[pvb]

Isn't the M31 the one which has a constant battery drain, even when switched off? Something to do with powering the "soft" on/off switch. I had one briefly, but thought it had rubbish audio as well, so sold it. Why not put it on eBay and buy a Standard Horizon?

 

[Sandyman]

Aim it at the skip.

 

[Plum]

Isn't the M31 the one which has a constant battery drain, even when switched off? Something to do with powering the "soft" on/off switch. I had one briefly, but thought it had rubbish audio as well, so sold it. Why not put it on eBay and buy a Standard Horizon?

You are right. It does suffer from constant battery drain. I am still successfully using mine, however, but always remove the when not in use to overcome the problem. Those that are not aware of the problem always think the battery has failed! Mine came with an empty battery tray as an accessory which i insert a set of alkaline non rechargable batteries for emergencies.

Www.solocoastalsailing.co.uk

Scs

 

[NorthUp]

Do I recall correctly icom produced a software fix for the power
drain, return to icom for a free update?

 

[TQA]

These guys do big battery business so their stock is fresh https://www.overlander.co.uk/

 

[William_H]

NiMH batteries in them selves do not suffer from being left completely discharged. Indeed with NiCad wet cells in aircraft a regular maintenance is to completely discharge the cells leave shorted over nigh then recharged. However Nicad and NIMH both suffer from the problem that as a series of cells (battery) discharges one gets to 0volts before the others and further current drain charges the low cell in reverse which is really bad for them. The low cell can become a short circuit so no more charging will help.
I suggest OP look into constant current discharge of the radio if this is the case you need to keep it on charge or charge often. It does however seem that battery is now dud and replacement cells would be the way to go. Not so expensive compared to a new radio.
The concept of a charger for NiMH and lithium ion batteries seems suspect to me. Voltages and charge regime are very different so that a lithium charger charging NiMH for a long time could cook the batteries. But then I may be wrong here.
good luck olewill

 

[JumbleDuck]

.
The concept of a charger for NiMH and lithium ion batteries seems suspect to me. Voltages and charge regime are very different so that a lithium charger charging NiMH for a long time could cook the batteries. But then I may be wrong here.
good luck olewill

The Li-ion charger is hella expensive, so I think it contains circuitry to sense the battery type and adjust charging regime appropriately.