Can you renew batteries on cordless phones?

Nikiya

I have a Siemens Gigaset C475 Twin Dect Phone set which has been losing charge fast and erratically. They are three or four years old. Unfortunately I cannot find the original instructions. Can I change/recharge their batteries? If so, where are they? I've tried disassembling the phones without success. Thanks for any help!

grumbler

Gigaset C470/C475

p.57



See this thread for replacement batteries: Rechargeable battery upgrade - dismal failure

Spank

Poundshop batteries work well as replacements

grumbler

grumbler wrote: »

Gigaset C470/C475

p.57

Why 57:huh: It's 8-9 actually.

ETA: I see, the 'recommended' batteries are on p.57, but I think you can safely ignore this.

Strider590

Spank wrote: »

Poundshop batteries work well as replacements

Don't do this, Ni-MH batteries can explode if overheated or overcharged, good quality Ni-MH have a valve to prevent pressure build up, but cheap Ni-MH can sometimes lack this valve or that valve way not be up to standard.
Fine if it's not something you leave unattended, but a cordless phone is unattended A LOT.

I would suggest buying GP Ni-MH (which is one brand that Siemens ship with the Gigaset models), they're not even expensive if you buy from a reputable UK eBay seller (other auction sites are available).

My phones came with GP 600mAH Ni-MH, last year I replaced them with GP 900mAH.

Don't take risks for the sake of a few £.

Nikiya

I managed to remove the lid!! Thanks! Can normal batteries (not rechargeable) be used???

stator

NO. You can't use non-rechargeable batteries, ever.

mac.d

If you just want to use them as a short-term fix until you get rechargable batteries, then yes you could as long as you don't sit the phone in its cradle* (although its probably safest to take stator's advice and just don't use standard batteries). They won't last that long, and as sitting your phone in its cradle automatically recharges your rechargable batteries, using standard batteries is potentially dangerous and a waste of money.

£6 from Amazon gets you 2 Eneloop Lite batteries that seem ideal for phones as they have a high recharge life.

*MAKE SURE YOU DON'T SIT THE PHONE IN ITS CRADLE, AS NON-RECHARGABLE BATTERIES WILL EXPLODE IF YOU CHARGE THEM*

grumbler

7dayshop sell 2x750mAh Eneloop for £3.49.

However, as was said in the thread quoted above, their own brand 4x1100mAH for £2.59 are perfectly fine.

The main feature of Eneloop - low self-discharge - is absolutely not needed for a cordless phone.

mac.d

The Eneloop Lite's linked to on Amazon were suggested because of their high recharge life (up to 3000), compared to the standard Eneloop's up to 2000, while the 7dayshop's own batteries are rated as good for up to 1,000 times. The reviews of the Eneloop Lite's suggest people reckon they are a good buy for cordless phones because of this. Doesn't that make sense? The low self-discharge isn't a factor.

Nikiya

Hello again and thanks for the links! The Eneloop batteries cost £6 for two at Amazon, so I'd need to spend £12 and either pay delivery or buy something else to reach £20 (and get free delivery). They are550 mAh.
The ones at 7dayshop are 1100mAh and it is 3.50 por a 4 Pack. I would not hesitate to go for these, since the difference is a lot but I have no knowledge of this subject, so your advice would be most welcome. Thanks!!