My manual states that there are 19 cells in the MA934 battery pack, and indeed that is what was in mine ( ex-Iraqi military). I was easily able to re-cell mine with generic Chinese made D size NiMH cells with solder tags on them. The capacity is a lot higher than the original Nicads, 7Ah. Due to the way these are wired and arranged it would be difficult to use a supplied made up pack, since these come shrink wrapped, so to speak. Maybe the lesser number of cells was to keep the fully charged voltage down a bit. I think you can find C size NiMH with capacity similar to the original Nicads, but I like having the extra capacity.

I certainly would not recommend using Nicads nowadays with more modern chemistry cells available, since they are prone to leak and the new ones mostly do not.

Dan

ac6ao / g3ncr

开云体育

In a message dated 01/03/2010 18:30:48 GMT Standard Time, danrae@... writes:

?

Scott Dorsey wrote:
> What has advanced in more recent years has been
> more charging than actual battery chemistry; lithium accumulator chemistry
> has been around for years but actually charging them consistently without
> wrecking them is nontrivial.
>
> The charging circuit in the Syncal-30 itself is just a constant-current
> source, sort of... Fine for NiCds, not really acceptable for NiMh, pretty
> much out of the question for anything else.
> --scott
>
>
>
You could well be right Scott, but since Nicads are getting hard to find
anyway, I will continue to use NiMH cells and charge them with constant
current, from the regular external charger who's number escapes me
(nothing in the Syncal itself), which works for fine me, so far...
Famous last words maybe.

Forgive my ignorance, but why is it not acceptable? I don't think I'm
alone in doing this!

Dan

Dan

?

Is the Racal charger you ention the 945S??

?

Stuart

Well, if there are 19 cells in the pack, that would explain why I had
such a hard time getting 20 cells in there.

The higher voltage per cell on charging probably reduces the battery
lifetime a bit.

I certainly would not recommend using Nicads nowadays with more modern
chemistry cells available, since they are prone to leak and the new ones
mostly do not.

That's fine if you have a charger for whatever other battery technology
you're going to use. What has advanced in more recent years has been
more charging than actual battery chemistry; lithium accumulator chemistry
has been around for years but actually charging them consistently without
wrecking them is nontrivial.

The charging circuit in the Syncal-30 itself is just a constant-current
source, sort of... Fine for NiCds, not really acceptable for NiMh, pretty
much out of the question for anything else.
--scott

Scott Dorsey wrote:

What has advanced in more recent years has been
more charging than actual battery chemistry; lithium accumulator chemistry
has been around for years but actually charging them consistently without
wrecking them is nontrivial.

The charging circuit in the Syncal-30 itself is just a constant-current source, sort of... Fine for NiCds, not really acceptable for NiMh, pretty
much out of the question for anything else.
--scott

You could well be right Scott, but since Nicads are getting hard to find anyway, I will continue to use NiMH cells and charge them with constant current, from the regular external charger who's number escapes me (nothing in the Syncal itself), which works for fine me, so far... Famous last words maybe.

Forgive my ignorance, but why is it not acceptable? I don't think I'm alone in doing this!

Dan

Stuartjmckinnon@... wrote:

In a message dated 01/03/2010 18:30:48 GMT Standard Time, danrae@... writes:


. Fine for NiCds, not really acceptable for NiMh, pretty
> much out of the question for anything else.
> --scott
>
>
>
You could well be right Scott, but since Nicads are getting hard
to find
anyway, I will continue to use NiMH cells and charge them with
constant
current, from the regular external charger who's number escapes me
(nothing in the Syncal itself), which works for fine me, so far...
Famous last words maybe.

Forgive my ignorance, but why is it not acceptable? I don't think I'm
alone in doing this!

Dan

Dan
Is the Racal charger you mention the 945S??
Stuart

After a trip to the garage to check; the MA 945 B, yes. I usually give the 7 Ah pack 24 hours instead of the 14 hours for the lower capacity pack. It's been about three years now, so far, so good.
dr

Forgive my ignorance, but why is it not acceptable? I don't think I'm
alone in doing this!

NiCds have a fairly wide charge range where they are happy. NiMH cells
are very, very easy to damage in comparison.
--scott