I have a set of Panasonic cordless phones, and each of the phone (KX-TGA740) uses a pair of AAA rechargeable batteries.

AAA Ni-MH DC 1.2V

However these batteries do not last long at all. I would buy a 8-pack and put them into all the phones, then once they are charged up they will last 2-3 days. I wait till they completely discharges and the phone says "Recharge for 7 hours" before I put them into the charging stations.

Well, after about a month or two, a total recharged phone will last for 4 hours of just on standby but if I turn it on for a phone call, it wouldn't last more than 15 minutes.

Now, this is perhaps partially due to me not taking it off the charging station after 7 hours. Sometimes they get charged over night, sometimes I forgot and left one charging for 2 days. I always wait till it says FULLY CHARGED but I simply can't manage the "7 hours no more no less" - too difficult.

My source for the replacement batteries are generic brands sold off eBay for that phone. Don't know if there may be better ones out there.

Is there anything I can do to extend these battery's useful life?

Is there some sort of special charger out there I can buy to properly charge the AAA batteries that will shut down once it's fully charged, then I can put them into the phones? Is this a better strategy?

Or are there better quality batteries than the ones I have been buying?

Or other charge/discharge strategies I should try?

Thanks in advance for any comments.

 

I don't use any discharge strategy. I just keep them on charge.

They chargers are somewhat automatic so an extra hour or two or a day shouldn't make any difference. Have you tried a different brand of NiMh batteries ?

 

I have three of the TG6512 series phones, same as yours I guess without speaking caller ID. I'm using the Sony CycleEnergy batteries, they last a little longer. Either Sony or the Sanyo Eneloop batteries are better than most.

Problem with AAA batteries is they are so small they just can't last that long. Like PJ said, and the book, you can leave them charging all the time without hurting the batteries.

Here is a link to the charger I bought for AA and it charges AAA also in any combination.

Amazon.com : Sony BCG34HRE4KN Cycle Energy Quick with Refresh Charger and 4 Pre-Charged 2000 mAh AA Batteries : Camera Camcorder Battery Chargers : Electronics


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