Archived from groups: alt.cellular.bluetooth (More info?)

Howdy:

I have some Motorola bag phone batteries, that I would like to recharge
thru my vehicle's cigar lighter, while on the road. The batteries I have
are SNN 4298 A -1 (sealed lead acid).

Making an adapter with a voltmeter (and ohmmeter if necessary) and
enclosing same in a covered battery box, is no problem.

What I need to know, is the charging times for the batteries, when
they're at various states-of-charge (or discharge, if you will).

IOW: X-number of hours for a battery discharged down to 11V; X-number of
hours for a battery discharged to 11.5 V, etc, when hooked up to the
vehicle's 12V 60A alternator.

I would really appreciate any comments and advice from readers who have
charged the same, or similar batteries, in this manner.

Thanks,
TD

Archived from groups: alt.cellular.bluetooth (More info?)

On Mon, 11 Jul 2005 13:32:17 -0600, teamdebus@webtv.net wrote:

> What I need to know, is the charging times for the batteries, when
> they're at various states-of-charge (or discharge, if you will).
>
> IOW: X-number of hours for a battery discharged down to 11V; X-number of
> hours for a battery discharged to 11.5 V, etc, when hooked up to the
> vehicle's 12V 60A alternator.

This depends entirely on the charging current, which in turn will depend
on the voltage. The output of the alternator will probably be closer to
14V than to 12V. You can get a sense of the level of charge by taking the
charger off and measuring the unloaded terminal potential. Here is a
guide from Yuasa-Exide: http://www.buchanan1.net/lead_acid.shtml. The
option of monitoring charge from the specific gravity of the acid is not
available with sealed gel cells.

In general you should limit the charging current to no more than 1/10 of
the numeric value of amp hour rating of the battery, i.e. charge at a rate
which will take at least 10 hours to go from empty to full. Any higher
rate of charge may result in overheating and deformation of the plates or
poor adhesion of the deposits onto the plates.

Tony

Archived from groups: alt.cellular.bluetooth (More info?)

On Mon, Jul 11, 2005, 9:21pm (MDT+7) not-for-mail@ahjg.co.uk
(Anthony R. Gold) wrote:

>In general you should limit the charging
>current to no more than 1/10 of the
>numeric value of amp hour rating of the
>battery, i.e. charge at a rate which will
>take at least 10 hours to go from empty to
>full. Any higher rate of charge may result
>in overheating and deformation of the
>plates or poor adhesion of the deposits
>onto the plates.

So, I shouldn't have any problems when charging the bag phone batteries,
with the vehicle's alternator?

Thanks, for the info. I appreciate it.

TD

Archived from groups: alt.cellular.bluetooth (More info?)

On Tue, 12 Jul 2005 00:19:54 -0600, teamdebus@webtv.net wrote:

> So, I shouldn't have any problems when charging the bag phone batteries,
> with the vehicle's alternator?

So long as you use the correct adapter and charger which will protect the
battery, it will charge fine. And you can use cheap camcorder sealed lead
acid batteries as replacements if and when the original Motorola one dies.

Tony

Archived from groups: alt.cellular.bluetooth (More info?)

On Tue, Jul 12, 2005, 8:39am not-for-mail@ahjg.co.uk
(Anthony R. Gold) wrote:

>And you can use cheap camcorder sealed
>lead acid batteries as replacements if and
>when the original Motorola one dies.
>Tony

I'm not familiar with camcorder batteries, but if they're 12V and will
fit inside my bag phone's carry bag, I'm all for it. That's great!

Another battery question comes to mind: Has anyone here, ever opened up
one of those plastic battery cases (like my bag phone battery has), to
get inside? Is there a way to remove the cover without breaking any of
it?

Can the contents be removed and replaced with rechargeable AA's, or do
the manufacturers usually epoxy everything (including the cover) in
place?

Thanks for sharing your knowledge!

TD