Thanks for sharing info on your battery setup, Jim. I was not aware that
Exide made a battery similar to the Trojan T-105. Which model did you
choose? The GC-110? A quick check on prices shows $113 to $120 for the Exide
and $125 to150 for the Trojan. Not much difference. Prices sure have shot up
in the last 6 months!

Cheers

Keith O

On Thu, Sep 4, 2008 at 10:20 AM, Jim Cochran <mxsailor@gmail.com> wrote:

> Hi List,
> I can appreciate the wisdom gained from the ham setup.
> I live on a sailboat most winter months and live off my batteries
> during much of that time. Have for 11 years.
> On my boat I use an external voltage regulator that allows me to dial
> up how many amps I want to push into the batteries, or set it to
> automatic and the regulator will figure how much my batts can take at
> any given moment when I run my diesel. I use 2 banks of Napa "Special
> Use" (Exide) 6 volt batteries, 4 in each bank wired to output 12 volts
> per bank, plus a group 27 starting battery. My regulator or 120 vac
> charger can charge 3 banks at the same time, sending different charge
> to each bank as needed.  Also equipped with solar panels and wind
> generator.
>
> Now that my Westy is running, I'll replicate that system using a smart
> charger for a bank of two Napa 6v batteries, with some solars on the
> poptop. The bank will live under the rear seat. The 6v can be
> discharged to zero and still come back (I've even had them run dry on
> me and still come back to life). Point is that the Exides sold by Napa
> are just as good as Trojans, without spending a fortune on them. If
> I'm camping on the water or dry land, I want the 6 volt wet cells.
>
> If you stop at 11.5 volts, you aren't going to have any capacity
> unless you have a monster bank of batteries. Most equipment with built-
> in battery savers kick in at 10.5v.
>
> On Sep 4, 2008, at 8:44 AM, Bill Prats wrote:
>
>  3. Did I hurt my Aux Battery?
>>>
>>
>> I have a large ham radio and have lots of battery experience, some
>> of the
>> brands don't last more than a few years.  Here is any easy way to
>> test the
>> capacity of a smallish battery.  Wire a tail light across it by
>> itself and
>> time how long the light burns a decent glow.  Since the wattage is
>> on the
>> bulb you will get a good idea about the condition of the battery.
>> Power in
>> Watts = Voltage times current.  6 watt bulb on 12 volts draws a 1/2
>> amp, 12
>> watt lamp on 12 volts draws 1 amp.  24 watt lamp on 12 volt draws 2
>> amps.
>> A 100 watt sound system full on will draw around 9 amps and more
>> depending
>> on other features and volume level.  A older 40 amp hour battery
>> might be
>> good for 2 hours in my opinion.
>>
>> Try not not to drain any battery below 11.5 volts, that level varies
>> by
>> battery but its generally accepted as the bare minimum before the
>> battery
>> plates warp and short together, bad news.
>>
>> Its possible the battery is ageing and the sound system draws far
>> more power
>> than estimated.  Put an amp meter in series with the system to
>> measure.
>>
>> The only sure way to find out the battery chemistry type is to
>> research the
>> brand/model number. Sometimes a deep cycle/gell or AGM will weigh a
>> few
>> pounds more than it automotive type cousin.  Well at least you get a
>> rough
>> idea.  I have the same problem, a 55 amp battery that weighs a ton.
>>
>