ICOM battery replacement

[davidej]

I have an ICOM M-31 handheld and the battery performance has been, to say the least, disappointing. It is not that old and now hardly hold a charge at all.

It is the Li-ion type and a replacement battery seems to be around £56 (half the cost of the whole set). I could by an alkaline tray for about £20 and put in some of those low-discharge NiMh (endeloop?). I would also have to get an new charging tray -or modify one of the many other chargers I have but i would, perhaps have a more robust package and certainly cheaper if they needed replacement again. The current Li-ion pack is marked at 1050 mah but you can get AA Nimh's up to 2500mah now

Any suggestions please.

 

[colind3782]

You can get batteries on ebay for Icoms for around £20. I have three Icom airband radios and that's where I get mine.

 

[rob2]

I believe the first M-31s with Li-ion batteries still had the permanent discharge arrangement which helped the earlier Nicad batteries avoid losing capacity by ensuring they fully discharged before they were recharged. Mine is the same and I pop the battery out a little when storing at home - this gives the battery a long shelf life and only needs an hour's charge before the weekend.

Rob.

 

[electrosys]

Although lithium-ion technology may be appropriate for devices which are typically used on a daily basis, as their 'clock is ticking' from the moment of manufacture, regardless of whether they are used or not - it is inappropriate (IMHO) for devices which may be used just a few times a year, or kept idle in a standby role. NiMH is a far more appropriate technology for such infrequent or standby use.

In addition, should a Li-ion cell's voltage ever drop below a certain level - as could happen during storage by self-discharge even after the smart controller effectively switches the battery 'off' - that battery can never be recovered.

Further - I have read that the M31 draws a small current from the battery even when the set is switched off, so the above scenario is more likely to occur with this particular model.

 

[davidej]

You can get batteries on ebay for Icoms for around £20. I have three Icom airband radios and that's where I get mine.

I can't find mine which is a BP-241- I would be grateful if you can point me in the right direction


I will take the other tip -I am going to recharge the battery, take it out of the set then check its state after, say, a week.

If all fails, I will probably go the Nimh route.

 

[davidej]

I wonder how hard it would be to open up the pack -solder a new li-ion in and reseal?

 

[chrisgee]

I believe the first M-31s with Li-ion batteries still had the permanent discharge arrangement which helped the earlier Nicad batteries avoid losing capacity by ensuring they fully discharged before they were recharged. Mine is the same and I pop the battery out a little when storing at home - this gives the battery a long shelf life and only needs an hour's charge before the weekend.

Rob.

Same here ,works well.

 

[electrosys]

I wonder how hard it would be to open up the pack -solder a new li-ion in and reseal?

The major problem is obtaining the cells: because they're potentially very dangerous in the wrong hands, reputable manufacturers won't supply Joe Public. Unknown makes can be sourced from China, via Ebay, but they ain't cheap, and the usual 'take a chance' caveats apply.

I researched this possibility last year to renovate my Thinkpad battery - but pretty quickly gave up. Have replaced 'em with NiMH's instead, which give half the capacity of Li-ion, but it's a more appropriate technology for occasional navigational use.

 

[TQA]

I wonder how hard it would be to open up the pack -solder a new li-ion in and reseal?

Not hard, buy a bat pack from a model supplier [ Overlander is good ] and either use the existing charge circuit or buypass it and use a model charger. You may want to be real carefull about running the bat flat if you go the second route.

I did this £7 instead of £70 and longer life due to greater capacity.

 

[davidej]

Post script

Following advice here, I fully charged the battery, them loosened it so it was no longer in contact with the set. From time to time, I pushed it back in and turned on to check the battery charge state.

After two weeks it has remained fully charged - which it would not do for two days if the battery was left in.

To me, it seems a design fault for there to be a current drain when the set is off. After all it is something that is used irregularly then maybe wanted in an emergency. NBG when you find the battery flat.

Thanks for the help.