Can NiMH batteries be recharged using a normal AA charger?

Wondering if I need to buy a NiMH charger for NiMH rechargeable AA
batteries or a normal AA charger will work with the NiMH batteries. Can
anyone tell me if this is possible?

Thanks in advance!

<deepaa@gmail.com> wrote in message
news:1114565054.117886.45800@g14g2000cwa.googlegro ups.com...

Wondering if I need to buy a NiMH charger for NiMH rechargeable AA
batteries or a normal AA charger will work with the NiMH batteries. Can
anyone tell me if this is possible?

If it claims to be a fast charger for NiCad cells then it's not a good idea
to use it with NiMH cells. If it's designed to trickle charge cells
overnight then it might work ok.

If your house burns down it's your fault though.

My battery charger is marked "Universal Ni-Cd & Ni-MH" and its not that new or special, so I would guess that most chargers would be OK.
Inside the unit, for AA batteries, it says Ni-Cd 500mAh - 5-8hrs Ni-MH 1200mAh - 10-20hrs
It seems like trickle chargers would work - you just have to allow time for the capacity of the battery. (or cell).

Alan

<deepaa@gmail.com> wrote in message news:1114565054.117886.45800@g14g2000cwa.googlegro ups.com...

Wondering if I need to buy a NiMH charger for NiMH rechargeable AA
batteries or a normal AA charger will work with the NiMH batteries. Can
anyone tell me if this is possible?

Thanks in advance!

"Z80" <r796coj@noSpam@blueyonder.co.uk> wrote in message
news:0KJbe.20509$G8.12198@text.news.blueyonder.co. uk...

My battery charger is marked "Universal Ni-Cd & Ni-MH" and its
not that new or special, so I would guess that most chargers would
be OK.

Fast chargers designed for NiCad cells (only) should not be used on NiMH.

The reason is because the end of charge voltage peak can be a lot lower
sometimes with NiMH cells - this can lead to the charger failing to detect
that the cells are full and fails to switch off. This leads to over charging
at the fast charge rate and possibly very hot cells or worse.

CWatters <colin.watters@pandorabox.be> wrote:

: "Z80" <r796coj@noSpam@blueyonder.co.uk> wrote in message
: news:0KJbe.20509$G8.12198@text.news.blueyonder.co. uk...
: > My battery charger is marked "Universal Ni-Cd & Ni-MH" and its
: > not that new or special, so I would guess that most chargers would
: > be OK.

: Fast chargers designed for NiCad cells (only) should not be used on NiMH.

: The reason is because the end of charge voltage peak can be a lot lower
: sometimes with NiMH cells - this can lead to the charger failing to detect
: that the cells are full and fails to switch off. This leads to over charging
: at the fast charge rate and possibly very hot cells or worse.

I've found that if I charge at high rates (1-2C) then the NiMh cells will
have a sharper dropoff and the delta peak will work on my old Tekin pulse
(NiCd) charger. If I charge at lower rates (< C) then if often won't
detect full charge and I have to check temperature. However, this
comment comes with caveat emptor and YMMV warnings. I have a 10 year old
(or older?) Tekin BC112 charger, still charging along...

DLC


--
================================================== ==========================
* Dennis Clark dlc@frii.com www.techtoystoday.com *
* "Programming and Customizing the OOPic Microcontroller" Mcgraw-Hill 2003 *
================================================== ==========================

On Wed, 27 Apr 2005 07:37:40 GMT, "CWatters"
<colin.watters@pandoraBOX.be> wrote:

deepaa@gmail.com> wrote in message
news:1114565054.117886.45800@g14g2000cwa.googlegro ups.com...
Wondering if I need to buy a NiMH charger for NiMH rechargeable AA
batteries or a normal AA charger will work with the NiMH batteries. Can
anyone tell me if this is possible?

If it claims to be a fast charger for NiCad cells then it's not a good idea
to use it with NiMH cells. If it's designed to trickle charge cells
overnight then it might work ok.

If your house burns down it's your fault though.

Please note charging overnight isn't "trickle" charging.
Overnight is standard C/10 charging (for the original charger
design cell capacity) although sometimes it can be as high as C/5.

NiMh shouldn't be (true) trickle charged (<C/20) in any case.
They may be never be charged fully or conversely depending on
the charge and cells, overcharged and lose capacity.