Rechargeable battery time again

aj2001

oh dear just read the last replys man o man, I also have the maplin charger abt 30is it was on some special offer. Got some aaa and aa batteries now worried lets be optimistic and hope its not the batteries.
i have some from 7dayshop and so far so good

Flimber

chrisw wrote:

I bought some from Lidl the last time they had them and they exploded. Trading Standards have asked me to send one off to Lidl for testing.

I put four 'D' cells on to charge yesterday and after about four hours (at ~470mAh/2V) they were too hot to touch and I turned the charger off and left them somewhere to cool - after first attempting to take a reading with a digital forehead theremometer (it was off the scale). Not sure what to do with 'em now. Would never leave these on an overnight charge as I don't trust 'em one bit to not attempt to start a family-killing inferno :rolleyes:

Mike.

chrisw

My exploding batteries were discussed on a thread here:

http://forums.moneysavingexpert.com/showthread.html?t=142630&highlight=exploding

The general concensus seemed to be not to put them in a fast charger but they should be alright on an overnight slow charger. I decided not to risk it.

dc

Flimber wrote:

I put four 'D' cells on to charge yesterday and after about four hours (at ~470mAh/2V) they were too hot to touch and I turned the charger off and left them somewhere to cool - after first attempting to take a reading with a digital forehead theremometer (it was off the scale). Not sure what to do with 'em now. Would never leave these on an overnight charge as I don't trust 'em one bit to not attempt to start a family-killing inferno :rolleyes:

Mike.

Batteries get HOT when they reach full charge.......camcorder and laptop batteries which are made up of lots of rechargeables in a pack, have inbuilt circuits that measure the temperature and switch the charger to indicate "fully charged" on the temperature rise.
Single batteries do not afford this "luxury".

I would suggest yours came out of the pack having been recently charged by the manufacturer.

It is good practice to discharge batteries completely before recharging, especially NiCad ones.

There is a SAFE charge rate whereby "ordinary" rechargeables can be left on charge continuously. It is known as the "Ten Hour" charge rate, being one tenth of the full capacity of the batteries, ( the current required to fill an EMPTY battery in TEN hours of charging).
i.e. if the capacity is 2000mAh then you can leave them in the charger if the charger charges at 200mAH or less, if it charges at a higher rate then you MUST switch the charger off when the battery is fully charged or it will overheat. Hence the Lidl and Aldi chargers have simple adjustable timers that drop the charge rate to a low rate after the set time.

With ref to Warnings on your charger, these usually refer to non-rechargeables, which are dodgy to re-charge.
The Panasonic warnings are to frighten you into buying their more expensive ones, a bit like your car manufacture will specify only using its own lubricants and recommend only using a certain petrol.

Generally most chargers wil re-charge most rechargeables. It is just a matter of working out how much each battery can store and Not overfilling it. :beer:
HTHs

rizla01

Now, I always thought that to correct the 'memory' problem on nicads all you had to do was drain them completely and recharge.

Or is this another myth?

PS Why are there no THANKS buttons on some of the posters here??

royalsteve

rizla01 wrote:

Now, I always thought that to correct the 'memory' problem on nicads all you had to do was drain them completely and recharge.

Or is this another myth?

PS Why are there no THANKS buttons on some of the posters here??

I believe that is correct provided you do this from day one

doozeruk

dc wrote:

Batteries get HOT when they reach full charge.......camcorder and laptop batteries which are made up of lots of rechargeables in a pack, have inbuilt circuits that measure the temperature and switch the charger to indicate "fully charged" on the temperature rise.
Single batteries do not afford this "luxury".

I would suggest yours came out of the pack having been recently charged by the manufacturer.

Well I would assume that these Aldi ones were not charged before coming out of the factory as they took a considerable amount of time to charge in my ultra fast charger! Usually I can charge a set of 2400mah in around 20 - 30 mins these took over an hour and were pretty much very hot.

The other thing about my charger (RIP) is that it was very, very clever (it scored loads of pluses and no miuses in its exams :rotfl:) it has independent micropocessor control of the charging process for each of the four bays, a whopping 4300mAh charge current and so uses thermal management including a fan to cool the batteries while charging:eek: It really was worth its weight in gold.

chrisw

I bought one of the Asda chargers with 4 2100 batteries for £7.97. This has a very low charge rate of about 150mA. I've bought a pack of the Aldi batteries, put them in this charger and they seem fine, only getting warm. They'll take about 16 hours to charge, but should get there in the end. I might go and pick some more up tomorrow.

penyekz

Anyone had problems using these rechargable battries? I've fully charged mine using my Hannel 200mah charger for 16 hours. The battries seem very hot. When I try to use the batteries on my Microsoft wireless mouse, it doesn't work. Not even a flicker of light. It also doesn't work on my handheld battery operated fan. It works on a remote control and small alarm clock but not the mouse. Any ideas? do I have a faulty set? I've tried 4 different battries and they are the same.

The battries has 1.2V written on it whereas my other recharables are 1.25V. Would this make a difference?

Stompa

penyekz wrote:

The battries has 1.2V written on it whereas my other recharables are 1.25V. Would this make a difference?

A standard alkaline AA battery is 1.5V, whereas rechargeables are typically 1.2V, and this can mean that they won't work in some cases. I've never had much luck using rechargeables in clocks for example.