Q: AAA NiMH battery recommendation for cordless phone

[TomBrown]

I would appreciate recommendations on AAA NiMH cells for a bunch of Phillips cordless phones. Each takes 2 x AAA cells.

The phones originally came with Phillips brand batteries that performed well for about two years.

After that, I tried the original Eneloops (I think 700mAh rated). They performed modestly for about a year and a half. They didn't have enough power to run the speaker phones unless hot off the charger and even then, only for a few minutes. At the end of a year and a half, the Eneloops were down below half of rated capacity. In every other application, Eneloops perform like rock stars for me so this was odd.

I'm currently using Powerex 1000 mAh cells that have performed well for about a year. When new, they would last 5 days on a charge and run the speaker phone for the first three days without trouble. After a year, they are down to 2 days between charges.

The Powerex were OK so I might just get more of these but I thought I'd solicit recommendations. I have some brand new Eneloop XX cells from Japan but I don't want to abuse them in a phone when far cheaper cells might do just as well and I have no need of LSD.

Thanks in advance.

 

[ChrisGarrett]

At what point will the price of NiMH AAA replacement batteries exceed the price of a new, more modern/efficient phone system?

You can try the XX Pros, just to see, but it seems that your phones kill batteries, so I'd be looking at something else.

My two Panasonic phones came with 2 ea. Chinese Pannie 400mAh AAA has their doing fine after a year and a half to two years.

Chris

 

[TinderBox (UK)]

I have been using Eneloop AAA 800mah in my Panasonic Dect Phones for a couple of years, one upstairs and one down, and i swap the phones over every 3 months or so to even the wear between them, as the down stairs phone gets used 95% of the time.
I have had no problems.

John.

 

[TomBrown]

How long do your batteries last on a charge? I would happily upgrade phone systems if I could get a week of standby.

 

[TomBrown]

I picked up a Panasonic cordless phone system about a week ago. The factory cells were broken in using a BC-700 and showed 320~350 mAh of capacity. I also have one hand set running a 1000 mAh PowerX cells that test out at 940mAh. Six days in, they are all still running on their first charge.

I'll run this for a few months and then throw a pair of Eneloops into one phone. I imagine the Eneloops will comfortably run those phones three weeks.

 

[caheaton]

I'm considering replacing the batteries in one of my Panasonic phones but have sometimes wondered if this might be a situation where ni-cd batteries might work better than ni-mh. Ni-cd can take more charge cycles and capacity isn't really an issue as the phone spends most of it's time sitting on the base rather than in active use.

 

[Don_Redondo]

Sounds like you have sorted this out but also sounds like what you were seeing is likely cycle life (number of times the cell can be charged) versus capacity. In general higher capacity cells have lower cycle life – which (on top of cost) is why a lot of phones come stock with relatively low capacity cells. This gives longer overall life with a tradeoff for continuous talk time or extended standby. Most phones use a constant low/trickle charge so essentially every day on the cradle = one charge cycle – or worse. For less frequent replacements go for high quality lower capacity cells. If you want more talk time or more time between charges go for the higher capacity cells but you will have to replace them more often. I have a Uniden Phone set that uses AAs. I use one mostly as a speaker phone and am often on extended conference calls. In that one I'm using the Powerex Imedions (a close second to the Eneloop XX generally at a better price). They are rated at 500 cycles. I do get extended talk time but they only last about a year. In the other phones I've used Eneloops and other lower capacity cells and get two years or more.

 

[Kouryu]

why not just use Eneloop Lites? They're recommended for DECT cordless phones anyway since the cells are rated for 5000 cycles