Derek..... Lead acid battery's aren't known for memory... the NiCad's have
that characteristic....
Okay now you said it was a Race car.... I assume it's got a Race car
ignition? Fan? Coil system? few other electronic goodies?
Tell me why it doesn't have an alternator? Seriously.... Don't poo Poo
this right off.... most the folks who race with me don't have
alternators...but I wouldn't consider running a car without one.... hell I
even have two battery's
The weight and drag of running one is significantly compensated by the 13.7
vts supplied to the system that if there is a loss it's on the wrong side of
the decimal point....
Just my thoughts.....
Keith ( http://downtown.ala.net/~kturk ) oh and I just got my second race
car that's wicked looking.... it's a 16' long Berkley I'm sticking my Rodeck
in...)
----- Original Message -----
From: Derek <dereklola@yahoo.com>
To: <shop-talk@autox.team.net>; <vintage-race@autox.team.net>
Sent: Saturday, June 21, 2003 9:42 PM
Subject: Battery Life
>
> Any battery experts out there?
>
> Is my race car battery about to give up?
>
> It's a Hawker Energy SBS-30 (Sealed Battery System) now
> about 3 years old. Has always been trickle charged with a
> "battery tender". While at the track I generally put the
> charger on every other track session (no alternator on the
> race car) and over the winter I've put it on about every
> three months.
>
> I was told last week that these batteries have a "memory"
> and if you frequently recharge without fully discharging
> them they will loose capacity. Recommendation was to
> discharge it (with a load like a light bulb) - then
> recharge.
>
> Sounds good. Here's what I found.
>
> Nominal capacity is 26 AH.
> Used a 12v 50W trouble light as load. I make that a 2.9 ohm
> load with initial current draw (at 12v) of 4.2A.
> 26 AH at 4.2A = over 6 hours capacity - right?
>
> I didn't check the no-load volts but with the 50W load it
> showed 12.1V, after 1hr 12.0V, 2hrs 11.7V - so far so good
> - then after only 3hrs the light was very dim and the
> voltage just under 7. Oops. Maybe it wasn't fully charged
> when I started.
>
> Recharged overnight on the Battery Tender. With it still
> attached this morning it was showing 13.14V - presumably it
> had been higher when starting to recharge but had settled
> back to this "holding charge" voltage. Right?
>
> 10 minutes after disconnecting the charger the battery was
> reading 12.77V. Switched on the load - only 12.32V. Hmmm.
> After 10 mins recovery (no load) it was back up to 12.66V.
> OK or not?
>
> Switched on the load again - only 12.2V. After 1 hr 12.1V.
> Then after 2 hrs only 8V. Hmmm. Worse than before. Switched
> load off - rose to 12V after few minutes, then 12.1V 1/2hr
> later - but it rapidly decreased as soon as the load was
> re-applied - back down to 9V (and decreasing) after couple
> of minutes.
>
> Did I damage the battery by what I did?
> Is it still OK? (i.e. is the above story typical?)
> Or is it about to give up in the middle of the next race?
> Anything else I should do?
>
> It is a sealed lead/acid, gel battery but the plates are
> pure lead which is supposed to be "good" (= expensive).
> Originally designed to aircraft emergency power.
>
> Thx for any info and advice.
>
> Derek
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