ICOM M31 charging

[bonny]

I recently purchased an ICOM 31 H/H and have read with interest some of the old threads regarding this item.
This is a great little radio in most respects. I tried a Silva S12 but found the volume control cumbersome (you press the Vol button and then turn the volume up/down with the chan up/down buttons, similar for squelch) at least with the M31 you have dedicaed volume buttons. Also the scan function is very slow on the Silva, approx 1 chan/sec.

The M31 is a great little radio, easy to use. but!!! it has 1 downfall. The "soft off" which continues to draw around 2mA from the battery when switched off flattens the battery. Leaving the unit on charge is not an option because this will fry the battery.

On charge (with the AC adapter) the battery charge current is approx 100mA. The battery is 750mAh therefore the charge current is 7.5hour rate, this ties up with the 8h charge time. At this rate, leaving it on charge continuously will damage the battery.

I have made a short lead with a 2.1mm plug on one end and a 2.1mm socket on the other end. In the middle I have put a 180ohm resistor in the +ve lead. I plug the AC adapter into one end and the other end into the charger. This reduces the charge current to approx 30mA which equates to a 25hour charge rate. At this rate it can be left on charge without worry and the battery will always be fully charged. The radio can even be left switched on (in standby it uses 20mA so battery is still receiving approx 10mA charge). The green charge LED just about illuminates

Cost approx £2.

 

[Manxman]

I started a thread some time ago about M31 and the battery indicator showing the battery was full, but next time you looked it had shut down because the battery was flat.

Corresponding with Jon Brookes at Icom he assured me that they would soon come up with a fix soon. As that was some six months since I now have my doubts

As he uses this forum, hopefully he will read your post, and make available to all of us, who have purchased the M31 a similar lead to as what you have made.
I'm sure a gesture like that could only be of benefit to Icoms reputation.

 

[mireland]

I own on of these sets and was baffled when it first happened to me. I read something about this recently in a mag. ICOM were saying that all soft switches were the same - like it didn't matter. It matters to us users. I too hope they produce a fix soon as this problem seriously undermines their set and their reputation. I had been told they were the best but feel let down.

 

[John_Clarke]

I agree this is most annoying. I keep my M31 in a grab bag with alkaline batteries installed for an emergency. The fix I am using is to release the battery retaining screw which is enough to separate the battery contacts and the radio will not run down the batteries. I have taped a coin to the radio to use to resecure the battery when required.

 

[aidancoughlan]

This seems a bit crazy, I've just ordered an Icom M31 at the LBS - one of the reasons I bought it was to have as a VHF for a grab-bag. The charger seemed like a good way to ensure the battery is always charged ready to go. It sounds like the charger is dangerous for the battery if you're not around waiting for the light to go green after 8 hours or whatever. If bonny can make a solution for £2, then why can't Icom include it with the radio, or is it available for £49.99 by chance?

ps. I've just done a bit of a google and havnt seen any indication that the chargers need to be monitored on blurb for Icom or other hand-held radios. Does anybody know if other hand-held VHF's overcome this problem - I'll consider sending mine straight back when it arrives for an alternative if there's one available.

 

[celandine]

Re: returning an ICOM M31

If you are going to return it I hope you did not buy it from Pumpkin Marine. I phoned them about this very problem with a recently purchased M31. I ended up speaking to the owner, and when I suggested that the set was "unfit for purpose" he promptly said: "that's your problem pal!" and put the phone down on me.

Mick

 

[JonBrooks]

Re: returning an ICOM M31

We have passed the feed back on to Icom Inc in Japan.
At this time there is no solution.

We recomend you remove the battery from the unit to maintain its charge.

If it is going in a grab bag this should not be an issue.

Each radio now comes with an advice sheet explaining the issue and our recomendations.

We would not advocate the method of constant charge.
All tests and history would indicate this WILL damage your battery.
This also goes for the "leave on whilst charging" we never recomend this.
I can not find any radio comapany that does.

If I can be of any further help please contact me here.

Regards

 

[ytd]

we have the ICOM lCM1V which has a rotary on off switch as part of the volume control. More expensive than the M31 though.

 

[JonBrooks]

[ QUOTE ]
we have the ICOM lCM1V which has a rotary on off switch as part of the volume control. More expensive than the M31 though.

[/ QUOTE ]

Only £50 now due to price reduction!