Cordless phone battery question

Stingray

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My battery pack wore out on one of my cordless phones so I went to buy a new one and they are around 20 bucks /ubbthreads/images/graemlins/confused.gif. It's simply 3 AAA NiMH's in shrink wrap with a connector. The thing is, the battery packs are all 3.6V and around 720 mAh. Seems to me I could just take 3 AAA NiMH at 800 mAh each and make a battery pack with 2400 mAh instead of 720 and it would cost much less too. Is there any reason this wouldn't work, would it ruin the charger in the phone base having such a higher capacity battery pack to charge?

I know homemade battery packs have been discussed a lot here but I couldn't find anything in a search about this particular issue. tia

Steve
 

raggie33

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well walmart has a decent uniden cordless 900 mhz for 10 bucks .it works great for me and comes with battery i dont know if that helps but it may good luck
 

Stingray

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Thanks, I saw that when I was there looking at the batteries. I could buy any of several different cordless phones for a little more than this overpriced battery pack. But...the phone I need it for is a 2 line 2.4GHz phone, and they're not as cheap.
 

PhotonBoy

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I've bought 4 AA sized NiCD cells at Radio Shack and used them to replace similar cells in my Motorola cordless phone. I had to solder them together. Saved about 50% compared to the regular, outrageous price. Later, I found I could have purchased a similar battery at a dollar store for about the same price -- not sure about the quality though. Next time, I'll check the dollar store first. After about 3 to 5 years, you're better off buying a new phone due to improvements in cordless phone technology.
 

Stingray

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Yeah, I know what you mean. My concern is whether making a 2400 mAh pack will burn out the charger in the base, and whether the charger will actually charge it all the way up.
 

Lynx_Arc

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your cordless phone pack is not 2400mah.... it is 800mah @ 3.6 volts since they are in series. It should work fine in your current charger, the worst that could happen is your charger may not fully charge it up but that isn't a big deal compared to the savings.
 

fivemega

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My cordless fax works with 2000mAh NiMH for several years. Much more talk time per charge but longer time for recharge too. Originaly it was 700mAh NiCd.
My cordless shaver benefits from 2000mAh NiMH which was highest at time.
 

legtu

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Battery capacities in a series connection are not added up. 3 x 800mah in series is still an 800mah pack.

Only slight problem with using a higher capacity pack is the longer charge time.
 

Stingray

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Thanks,...I totally forgot that the amperage wasn't added up when in series, just the voltage....opposite of parallel where the voltage stays the same and the amperage gets added. I used to know that almost instictively, I'm getting old.

On a similar note....I just got over a serious injury and haven't been hanging around CPF much like I used to. It's really amazing how much things have progressed and how many new products are out in just the last 6 months while I was away. U binned LUX III's....prime T bins in ample supply, strobing tactical lights...awesome new EDC lights...I gotta get caught up now.
 

blr

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ou can make youself a new pack. If you can solder, get 3 AAA cells with soldering tabs, salvage the connector from the original pack and solder the cells and the connector as it was done in the original pack. Finally you can pack it in a shrinkwrap. It will be much cheaper than buying the original pack. Be sure to get cells with soldering tabs, do not solder at the terminals of ordinary cells.
 

Lynx_Arc

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You can solder tabbed batteries, just have to be careful to not overheat them. It may require sanding them if there is a plating on them that doesn't solder well to. If you had got ahold of me months ago I could have gotten you the batteries for cheap. I still have a lithium ion cell phone pack that fits in place of a 3AAA if it is the right one for your phone. I think it fits a nokia.
 

VidPro

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we upped all three of our 2 line 900mgz phones from the trashy ni-cad AA 800ma packs to 2400 ni-mhys. years and years ago. and i have not had to replace , switch to the backups, or forced to cycle them since.
the charger takes 3 DAYS to fully charge , what took only a day before, but it runs for 2 weeks now off hook, and i have never seen it be dead yet.

i just slopped them together, watching the heat like lynx said, used properly broken razor blades to make the type of flat connections it used, and wrapped it in vinal electical tape.

i still cycle them once a year anyways.

but with AAAs , the off the shelf isnt going to be much more power , than what you can do yourself, other than save money, and use brand name cells of quality.
 

Lurker

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I also use NiMH packs of much higher capacity (more than double) than the original Ni-Cd in my Panasonic cordless phones. It works great and makes the phone much more usable. I have been using the same Ni-MH pack for seven years! I leave it in the charger every night. I never cycle the battery on purpose, but very ocassionally it gets discharged through normal use. They outlast the phones. It is amazing.

I don't know why they last so long, maybe it is the very slow trickle charging.
 
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