[ausev] Batteries not getting up to charging voltage?

[Brian Lasseter]

On Tue, Jun 9, 2009 at 3:30 PM, Roy Holder<roy at holder3.com> wrote:
> As the flooded batteries get older the internal resistance increases,
> diverting more of the input and output voltage and amps into heat production.

I didn't mention the heat thing in order to keep my email simpler...
but yeah, I've noticed my batteries getting much hotter when they
charge, and when they are used.  (To the point where adding additional
airflow into my trunk seems like more of a necessity than a nice to
hage.)

Since I keep detailed records of miles driven, and kwh dumped into the
car... I'm also noticing a decrease in efficiency.   This would then
be due to exactly what you said... energy going into heating the
batteries.   :-/


> As they continue to age the internal resistance will increase to where the
> charger will not turn off automatically, and you will need to closely
> monitor your battery charger.

Seriously... I'm starting to learn that.


> The batteries will also likely begin to self discharge as a noticable rate,
> (for me) from a full charge to a half charge(or so) over a 3 day weekend.

Huh... I had not noticed that yet.  I actually let my car sit for the
two weeks that I was out of town recently (May 22 to June 7) and the
Xantrex eMeter said the batteries were only at 85% of charge after two
weeks.  (Obviously the eMeter can't measure self-discharging so well,
but it did say that the pack was at 141V after all that sitting...
which made me feel good that my parasitic loads and/or ground shorts
were not very big.)   Driving the car, it seemed a little more
sluggish than the 85% charge indicator would have me believe, but it
wasn't much lower.


> Yesterday I made it to work and home on 1 charge, but the voltage was very
> low by the time I got home.  I travel up and down north 183 often at 50+mph.

My work is pretty close, but I'm at the point now where I am unsure
that I could travel to downtown and back on a single charge.  (30
miles)


-- 
TTFN,
Brian "Lasso" Lasseter

"No Sane man will dance."   -Cicero (106-43 B.C.)