Rebuild cordless phone battery pack

Isn’t an application like that (constant charge) particularly bad for LSD cells? I’m assuming phones like these just have a constant trickle charge, at least mine do but they are really old.
I just suck it up and buy replacements when I finally have to. They last 3-5+ years.

the panasonic phones have some intelligence in their battery chargers.
the ones we use at the shop have 3 aaa cells that are user replaceable.
they went 6 years till i needed to replace them.
ir was several ohms.
they would still run several days standby but reboot if you answered or initiated a call.

This is a nice place to put those non low self discharge batteries since they will be sitting on a charger 24/7.

Easiest answer is to replace the phones . Like people have previously stated they are everywhere and cheap as dirt since all the cool kids are using cell phones exclusively and the home phone and it's bill is gone for good .

ours are linked to a cell via bluetooth.
its built into the base.
so we have 5 handsets on 1 cell.
works out nice.
the panasonic systems are the best out there.
i would fix the op’s system rather than roll the dice on another system.

I have had good success with cheapie rechargeable cells from Menards. I think they are marketed to be for solar lights. If you catch them on sale or with a rebate you can get them REALLY cheap. I have also tried white eneloops in my Panasonic cordless phones (that take two AAA cells) and they only worked ‘okay’. I always try to run the handsets/cells all the way down before putting them on the charging base which is fairly easy for me because we have 5 handsets (and I only put out 3 bases).

Do the older Panasonics have intelligent chargers? eg. PQLV30030ZAM like this:

We also have some newer ones that take individual AAA cells and I’m more confident those use some intelligence.

Yes, it would be easier to simply dump the old sets, but I just dislike wasting something that is perfectly functional just because the batteries are worn out.

I’m not in the US, but damn, $3 on sale for replacement battery packs is great: https://www.menards.com/main/electrical/batteries-battery-chargers/jensen-reg-cordless-phone-replacement-battery-jtb104/jtb104/p-1444424464012-c-6303.htm Even if the cells aren’t the best, that would beat trying manual repairs.

The Panasonic set I’m familiar with seems to have ‘intelligent’ charging. I’m unsure of its age, but the handsets use AAA cells.

Occasionally, a handset sitting on a charger will chirp and indicate ‘Charging’ on the display. This leads me to think that they aren’t constantly being charged while on the bases. Does your set do that?

Oh… good point. The handset does actually display “Charging” and then “Charge complete” while on the charger, though the charger’s red “Charge” light always remains lit while there is contact.

Forget reading the manual, sometimes just reading the handset’s display will do!

With my Panny phones (model KX-TGA641) if the batteries have been removed/replaced when you put the handset on the charger they appear to get a full charge even if the batteries were already charged (like by an external charger) so be careful.

+1. My Pana KX-TG6445T phones, which accept standard AAA NiMH cells, do not appear to have intelligent charging and wear down cells more quickly than I would expect. If you remove/replace the cells, they will always be charged for many hours as though it’s simply a timer system, though the phones do have some concept of “charging” and “fully charged”.

If I remove cells for any reason, I must discharge them completely before re-insertion. I’ve had a serious hatred of dumb chargers since last century :wink: .

My last replacements were Amazon Basics as they were then available in a 12-pack for a good price. They’ve held up so far, but…

I’ve also got 1 handset that randomly cooks its batteries for no apparent reason as though it constantly thinks that new cells have been inserted. If I see the light staying on, I will check to see if the battery area is warm and then lay it off the charger for a day or two (until a family member finds it off the charger and “helpfully” sticks it back on :person_facepalming: ).

This happened frequently last year, but hasn’t happened in the past few months. No idea why.

Thanks for the warning. Smart charger that first cooks cells… just why.

We have a newer set that takes individual AAA cells that looks like KX-TGA652. The battery packs in this thread are for KX-TGA542M handsets. No idea about its culinary tendencies.