Free battery chargers, hurry only 10 million left.

DividedNation

Where to get them from?

Well you may already have one.

I have just realized that hands free telephones all come with a charger, so, particularly if you have more than one handset (you want to have a phone available for calls) you can use one of them to charge rechargeable batteries.

It may be obvious but I have only just realized this!!

Indeed if you only have one set you could still put dead batteries in it and it would at least ring
when charging.

Although having said that I have noticed some odd thing such as the dead batteries I took from a handset recording a higher voltage than ones I had previously charged in my charger, well anyway as I remember the charger only charges them to about just over 14 volts, ie about 14.2
but the one I took from a handset which had 'died' showed a charge of over 15V,

Sorry if the last bit is rather confusing, I am rather confused about it myself, I notice the shop
bought rechargeable batteries hold a lower charge about 330maH where as the ones that came with the handset are over 500mAh.

Maybe someone one else can shed some light on this, the charging bit is confusing are, when I first got the shop bought rechargables I was a bit surprised they were only about 14.2V fully charged on the charger I bought. Maybe the handset charges them higher?
Well I ill get you know as I am charging some of the shop bought batteries in the handsets now.

(one of the handsets if form an old handfree phone I no longer use but kept).

So I may add an update when they have been on charge for longer.

But the main point was I never realised I could use the handset to charge other batteries, or at least try to, I have not had them in the handset long enough to charge them fully so I will have to see what happens tomorrow.

d123

I think you're posting in the wrong section, this section is mobile phones, not DECT cordless phones.

forgotmyname

Except the charger is probably designed for ancient nicads which is the ideal solution for phones but not other battery types.

Charge other battery types and wonder why they die quickly.

DividedNation

d123 wrote: »

I think you're posting in the wrong section, this section is mobile phones, not DECT cordless phones.

I posted this in freebies, it seems someone moved it here.

Maybe the people who sell battery charges complained, I don'[t know you tell me.

DividedNation

forgotmyname wrote: »

Except the charger is probably designed for ancient nicads which is the ideal solution for phones but not other battery types.

Charge other battery types and wonder why they die quickly.

I think you may be right about the charger, it is a dumb charger anyway, I think it said to charge for about 18-20 hours iirc, however.... I just looked and it said on the back NiMH.

Anyhow I got onto the topical when my two year old handfree phone died during a call of about 10 mins, it is supposed to be 14 hours talk time!!

I am a bit confused about the whole thing, I have various batteries, one I bought form poundland charged to about 14.2V where as ones I took from the phone were more like 15.5V

I always thought the 14.2 was low, most disposable batteries seems to be closer to 16V.

Even in the phone charger base unit the poundland only were charged to about 14V.

It is a confusing area though, a battery might show a high initial voltage but discharge quickly.

I is not easy to determine how much charge a battery will hold, I have been putting them in an LED torch and leaving it switched on and seeing how long it takes to drain the battery, but it is a long time I think I worked out about 12 hours based on 0.02mAmps per hour drainage.

I have put the phone into an eco mode which should save power but clearly 10 mins is not good enough for phone calls.

I took some batteris from an older phone base set which were about 15.5v but left outside the phone doing nothing they wer down to 1.2V so clearly no good.

d123

DividedNation wrote: »

I am a bit confused about the whole thing, I have various batteries, one I bought form poundland charged to about 14.2V where as ones I took from the phone were more like 15.5V

I always thought the 14.2 was low, most disposable batteries seems to be closer to 16V.

Even in the phone charger base unit the poundland only were charged to about 14V.

It is a confusing area though, a battery might show a high initial voltage but discharge quickly.

I is not easy to determine how much charge a battery will hold, I have been putting them in an LED torch and leaving it switched on and seeing how long it takes to drain the battery, but it is a long time I think I worked out about 12 hours based on 0.02mAmps per hour drainage.

I took some batteris from an older phone base set which were about 15.5v but left outside the phone doing nothing they wer down to 1.2V so clearly no good.

If you're talking AA cells, there's no way they would be reading 14v - 15.5v.

A rechargeable AA is 1.2v, a non rechargeable is 1.5v and a rechargeable NiZn AA is 1.6v.

Did your cordless phone take a battery pack of some type?

If it takes AA cells, don't buy the rubbish in Poundland, look for decent quality brands like Sanyo, Panasonic or Duracell.

cts_casemod

I'm trying to make sense of this post too.

Recheargeable Ni_Cd and Ni_MH batteries have a nominal voltage of 1.2V with a charging range (high threshhold) of 1.45 - 1.55V and a settled, fully charged, open circuit voltage ranging somewhere between 1.3 - 1.4V.

Most disposable batteries come fresh with about 1.6V, open circuit voltage.

Are you posting your results with the comma on the wrong place? I dont know of any 'disposable' batteries that read closer to 16V?

Older batteries tend to have an increased internal resistance. They may well have higher terminal voltage than a healthy new battery and they reach this value very quickly since their capacity is degraded.

Immagine a water bottle. A new battery is a 2L bottle. If the tap flow rate is 1l/minute, it takes 2 minutes to fully fill such bottle. Now as the battery ages, its capacity reduces. Say a 330ml bottle. Using the same tap, at the same flow this would take 1/3 min or 20 Seconds to fill.

The same is valid when you put the battery on the phone the lower capacity means the battery cant keep up and its voltage drops very quickly indeed. As a result the device is starved and unable to operate correctly.

As to the different capacity, I would not worry too much with that. Most manufactureres inclusive lie on their ratings, there are also cases of banned Ni_CD batteries being imported to Europe as Ni_MH and everything else in between. Rather than speculating it would perhaps be better if you told us what size these batteries are. I'm guessing AAA...?