Charging Batteries

CrazyChemist_2

I have bought 4 x AAA high capacity (900mAh) rechargeable batteries. I've charged them up using a NiCad charger as I was told it would be ok to use that to charge them up, by the guy who sold them to me. :think:

However, the AAA batteries don't seem to last very long at all (in a digital camera with medium usage) and are a bit disappointing. I'm using a NiCad charger which supplies 140mAh of current to the batteries. It is an old one which doesn't cut off, so apparently I have to be careful not to leave them on charge for too long.

Can anyone lend some helpful advice about these problems as I'm a bit puzzled about Ni-MH batteries - is it right that they don't suffer from the memory effect that NiCad batteries do? If so, why are mine being so sluggish? And what happens if I do happen to leave them on charge for too long

Any help much appreciated

CC :beer:

elvis_bloggs

I have to leave my batteries on charge for 8 hours, my charger has automatic switch off but it won't switch off until the 8 hours are up, I believe it is better if your batteries are absolutely flat before charging them.

Whitefiver

Hmmm, whilst there are dual purpose chargers, I believe that NiMH batteries need different voltages/current or the like to NiCds - maybe that's the problem?

When they are charged, then they should carry more "power" than the equivalent NiCds, I believe, and yes, they are said not to suffer from the memory effect. Still better to let them run down totally occasionally though.

Hope that helps,

Regards,

White.

jon_r_2

yes,'nicads' have a memory effect, ie if you dont TOTALLY discharge them, they will not fully charge up, also new batts do need to be charged fully then discharged fully say 3 times, it is only then that they work at full capacity.

i have found even the later generation of batteries do need to be treated in this way. i deep discharge my mobile battery every 3 cycles,to prolong its life, thats 9 times out of 10 why they appear to become useless, ie shortened life

hope that helps! (sorry,duplicate info! White you posted as i was writing!!)

arealhighlander

900mAH are not very powerful (do you mean AAA and not AA for digital cameras?)

I use 2300mAH ones.

And, yes, if they are new, they will need a full 8-10 hrs charge and you should use a suitable NH-MH charger and not an older Ni-Cad one.

egbe

I think you would be better off long-term to get an automatic charger, such as the ones used for phones.

The old constant-current Ni-Cd chargers were intended to be used for 12 to 14 hours at a current of one-tenth of the capacity. The difficulty is in knowing how much to recharge in the case of only partial discharge, and there is a risk of damage through attempted overcharging.

More modern fast-chargers such as for phones detect the amount that the battery is charged already, and cut off when ready, but even these then trickle charge the last part and say they should not be left on for too long.

CrazyChemist_2

Is there any risk of damage to these new ones since I used a NiCad charger? Also how much do these newer automatic/intelligent chargers cost?

Also I've only ever seen 900mAh as the highest capacity AAA for my digital camera. Are there really higher capacity ones out there?

amd

You shouldn't have done any damage with your old charger - you just probably haven't charged them long enough. However, I would get a new NiMh charger - mine is a superfast charger by Uniross, it does 4 AA's in about 2 hours with auto cut off. The quicker you want them the dearer it gets. Mine was about £30 a year or two ago - much more choice now.

Also, AAA batteries aren't as high powered as AA's. 900mAh is about top whack at the moment for a triple A.

CrazyChemist_2

yeah, that's why I'm annoyed that my camera was made to take those and not the AA batteries :mad: but then the camera is pretty small for a 3MP

I've looked in Argos and their chargers are pretty steep - are there any other places I could get one from a bit cheaper? Apart from Argos I have no idea where to look

Whitefiver

They are not quick, but www.7dayshop.com should be able to help you.

Where I get my batteries/chargers from.

Regards,

White.

amd

Maybe you should start by thinking how fast a charger you want - or what batteries they come with. Have a look at the Uniross site and then decide which is the most suitable. Then do a Google on it or go via Pricerunner or Kelkoo which will throw up lots of prices. Some sellers on Ebay too.

Look out for the size of batteries that come with the charger. For instance the 'X-press 300' comes with either 1300mAh or 2300mAh AA's depending on where you look! Seems like not a bad model - should do your batteries in about 9 hours! Can you wait that long?

I haven't seen a charger that comes with AAA's which would give you a back-up set for the camera - very useful, especially if it takes 9 hours or more to charge! The Uniross site gives loads of information on charging times and how to get the most from your battery.