Radio battery charging

[Jim Snyder]

So my lithium battery in my Standard Horizon radio failed after about 2 years. I was talking to the tech support because the battery was still metering at the rated 7.5 v but wouldn't power up the radio. He said that it would drop immediately upon being loaded which my meter just confirmed. 

The interesting thing he told me which is the reason I'm posting is that I was ruining my battery by leaving it in the charging cradle all the time, that I should only charge it when it is low and then remove it from the cradle. What experience do others have?

[EEL]

Jim:

Lithium batteries are rather complicated devices about which I know little.  However the following might be helpful:

1.  They like being cool and do not like being warm;

2.  They deteriorate the most when fully charged or discharged to the extent the protective circuitry allows;

3. They are happiest when kept in a range of @30% to 80% charged:

4.  The happier they are the longer they will last:

5. No matter how happy you make them, they will eventually die of old age or having gone through an established number of full charge/discharge cycles.  Which in both cases is less than many assume;

6.  When you leave it in the charging cradle, the charging circuity will not allow it to get to its happy place and instead keep it fully charged causing it to fail sooner rather than later as it is being kept it in a state that will cause it to deteriorate more quickly.

I suspect what you experienced is the battery no longer had any useful working capacity, meaning it had no ability to actually supply current, but it would charge up to the rated voltage so the charging circuitry thought all was working OK since the battery showed the rated voltage across a high resistance through which essentially no current was drawn.  Turning on the radio immediately drained it of what little working capacity it had.  This is not a binary situation.  For example a battery might have adequate capacity to operate a radio on receive for a long time, but the current draw to transmit is much higher and transmitting will deplete the battery very quickly.

Ed Lawson

[mhabich]

Also watch for corrosion on battery contacts.

[gyork]

I only charge my battery once a year, in the spring before paddling season, and have depleted it to ~0 once, purposely, having read that it might be good to do from time to time. My Icom M88 is still going strong after 15 years.

g

Edited November 26, 2020 by gyork

[David M]

Jim,

After thinking I was  mitigating an anticipated low charge and routinely cradling my radio, having  a battery fail, I had a similar conversation with a tech and now follow Gary's practice.  I may have to charge the radio twice per season if I've mistakenly left it on between paddles. 

Edited September 18, 2020 by David M

[EEL]

Gary:

Given it is  potentially a matter of life or death, you might want to replace that 10 year old battery.  It is definitely at the outer limits if not beyond.

Ed

[Jim Snyder]

My new battery arrived and sadly it refused to charge either. I got to work with my meter to try to trace the failure. There was good voltage at the charger so I cleaned the contacts on the side of the radio with electrical cleaner. Still the contacts in the battery housing seemed to have low voltage. I reluctantly disassembled the case and cleaned the four internal contacts.

The voltage at the battery contacts went up to .6 v. I have no idea what the voltage should be but the charging icon came on when I put it on the charger. On a whim I put the old battery back in that the tech told me I had ruined charged right up. Now I have a spare battery.

[gyork]

On 9/17/2020 at 12:42 PM, EEL said:

Gary:

Given it is  potentially a matter of life or death, you might want to replace that 10 year old battery.  It is definitely at the outer limits if not beyond.

Ed

FWIW, Ed/others, just reviewed my "kayak receipts" file, and determined the radio with original battery is 15 years old! During this past weekend's Jewell Annual, I had the radio "on" for each day trip, for a total duration of ~ 20h, with multiple transmissions/receptions. At the start of the WE, the battery indicator displayed a level of 8.2; at the end of the WE 7.9.

I may be an * it, but you already know about my attachments to boat/car/ wife.

[prudenceb]

11 hours ago, gyork said:

FWIW, Ed/others, just reviewed my "kayak receipts" file, and determined the radio with original battery is 15 years old! During this past weekend's Jewell Annual, I had the radio "on" for each day trip, for a total duration of ~ 20h, with multiple transmissions/receptions. At the start of the WE, the battery indicator displayed a level of 8.2; at the end of the WE 7.9.

I may be an * it, but you already know about my attachments to boat/car/ wife.

What's an *it? ?

[gyork]

21 minutes ago, prudenceb said:

What's an *it? ?

I may be an ass-ta-risk (*) it,........

[Jim Snyder]

Just as a followup, I've been on a couple of trips and the battery is holding a full charge. I will wait until it is below 50% to charge it. 

[EEL]

Gary:

Admit I have a similar tendency to hang on to things, but cannot match your receipt retention for sure.  I wonder what type of battery your radio has.  It may not be a Li-Ion.  My favorite radio is similar aged SH HX270S which keeps chugging along and replaced battery at @10 years even though seemed fine.. It uses a Ni-MH battery. 

My ham radio VHF radios are used far more than the marine VHF radios, and their batteries need replacing more in line with the suggestions I gave.

 

Jim:

I like your DIY spirit and willingness to open it up and do some work on the contacts.  Takes very little to inhibit a good electrical contact and these radios are used in a very corrosion prone environment. 

Ed Lawson

 

 

 

 

 

[Jim Snyder]

25 minutes ago, EEL said:

Takes very little to inhibit a good electrical contact

The point of failure was a spring to plate contact inside the case. This can't be helped where the battery contacts are but it seems like a design flaw to have a connection like that buried internally.

[gyork]

On 10/6/2020 at 11:45 AM, EEL said:

Gary:

I wonder what type of battery your radio has.  It may not be a Li-Ion. 

Ed Lawson

 

Edited a screen shot of my IcomM88 owner's manual, found on-line:

Edited October 21, 2020 by gyork