[svzephyr44]

I have a couple of handheld VHF radios. They have been living in the charger without much use. Now the batteries have memory. They are fully charged. When I key the mike they fully discharge. No amount of charge cycles seems to break this outcome.

Is there a quick way to kill battery "memory" or am I stuck purchasing new battery packs?

 

[Minnewaska]

I thought the idea of battery memory was a bit of a myth for modern batts, but I don't know.

Anyway, I doubt it's good to leave them in the charger full time, unless the charger is smart enough to know its done. You can overcharge a battery, which may be your problem. Either way, I'm guessing it new battery time.

I wouldn't know when they are or aren't being overcharged, so I charge till the light tells me they're done and then let them sit off the charger. My portable handheld's batteries will hold a charge for a really long time, when not in use and off the charger. Both are standard horizon models.

I sort of go around and charge everything on the boat up a few times per season, unless they are in use and then recharge at that time. Amazing how much rechargeable crap we collect these days.

If it's needed for emergency use (such as the radio in my ditchbag), I keep the adapter to use alkaline batteries and a good supply of them in there too. You might consider just going that route, if you're buying a new battery anyway. Not as eco friendly and more expensive, however.

 

[hellosailor]

zephyr-
That is not necessarily "memory". Which all majors vendors (like SAFT, who own the NiCad trademark) claim is not a problem for any major brand with new technologies for the last 20 years.

The batteries may simply be cooked, from too many hours on a cheap charger. Chargers aren't all the same, not all can be run all the time.

"Memory" is when NiCds or other cells are always cycled from full to a certain discharge level, which causes crystals or other physical changes to happen. When the same cycle is repeated often enough, those crystals (or other chemical changes) repeat and reform, reinforcing themselves at that one discharge state. To break the physical change, you need to use the batteries, full to dead and back again several times. Some will say to use a higher charge voltage as well, with time and current carefully limited.

But the bigger question may be the battery TYPE and AGE in those radios. 300 cycles may be full life for a lithium type. 500-1000 tops for NiCd and NiMh, and they won't have full power anywhere near that long. Exactly what you've got is important. If they're five years old, regardless of what they are, it would make more sense to replace them.

 

[Classic30]

zephyr-
That is not necessarily "memory". Which all majors vendors (like SAFT, who own the NiCad trademark) claim is not a problem for any major brand with new technologies for the last 20 years.
.....

Bloody clever of them really: trade-marking an abbreviation they know will become common use. SAFT are best known around the marine industry for their NIFE (ie. Nickel-Iron) batteries.

...but I digress. Carry on.