triumphs
[Top] [All Lists]

Re: Battery not overcharging

To: JAMES_S_WALLACE@HP-Canada-om1.om.hp.com
Subject: Re: Battery not overcharging
From: Thomas Howard <thoward@sdcoe.k12.ca.us>
Date: Tue, 17 Feb 1998 20:43:47 -0800
Cc: triumphs@Autox.Team.Net
 
>     Why not? Any (constructive) comments? 
>     
>     Please respond in terms of electrons rather than molecules if 
>     possible, as I'm chemically-challenged but electronically-oriented.


Jim,

One can certainly build a charger to keep a car battery at peak during
months of dis-use.

The only trick is to know a bit about the battery involved.   Such
batteries have several paramiters that effect the state of charge.   

The capacity of the battery, the internal currents, and such.   Temperature
can also play a roll.   As stated in other postings one wants to have just
the right amount of current going into the battery to replace that charge
that is lost.   This value will be different for different batteries and
conditions.  

That leads to an electronic solution.   A power supply that will adjust its
output to match the requirements of the current (no pun) conditions.

The typical requirements are in the range of 100-500 milliamps.   The
voltage required to produce this value will change depending of the current
state of charge, age, and condition of the battery.   

There are comercial products that address this requirement but those tend
to be simple devices that are better than nothing, better than a standard
battery charger but less than a good constant-current power suppy can deliver.

Keep in mind that a brand new battery is about $30.00.   Money spent on
maintaining an old battery so that it can be re-used some year/s down the
road might just be a false economy.   This, and the need for a place to
keep the "charging" battery, the possibility of a hydrogen gas buildup, a
place to plug-in the charger to keep from tripping over the wires are all
problems.   Just recycle the old one and go with fresh when required.



Thomas Howard
1972 Triumph GT6,
(& a good bit of USA iron)


<Prev in Thread] Current Thread [Next in Thread>