[Vwdiesel] Rabbit Batteries -1 or 2 ???

[gary]

Ok, I have to chime in here...

Look at this site. It will tell you more than you need to know about US
Submarine batteries.

http://www.fleetsubmarine.com/battery.html

I rode nuke boats for 15 years(same set up). I speak from 1st hand
experience.

These batteries provide...
210-355vdc
5000amps for 1hr
2500amps for 3hr
10,000amps for 10hrs

No small pittance!

Two auto batteries wired in parallel should not be a problem. Using two
identical batteries does alleviate most problems.

Something to consider, all batteries have internal resistance. I
wouldn't be too concerned about overcharging one battery over the other.
As the 2nd battery approaches full charge, its Vt rises, the difference
between Vt and Vo becomes less, and less current will flow into that
battery.

Moreover, the problem of concern would be when both batteries are almost
exhausted. Because each battery has internal resistance(never the same
from one to the other), one battery could completely drain before the
other, and would reverse. This is not good, and should be avoided at all
costs.

Go for it!

-Gary in Orlando
CPO USN (Ret)




On Mon, 2003-04-21 at 13:11, H .Hagar wrote:
> This is a multi-part message in MIME format.
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> [ Picked text/plain from multipart/alternative ]
> Roger Brown --the battery in diesel subs are what I call MOAB's , as to c=
onnections  I forgot.The cells were long skinny things . About a  foot squa=
re and very tall.They have to be small cells for easy replacement.Being so =
small they were likely a combination of series and parallel cells.I was sta=
nding on one while the cells were lifted out.(British sub)
> Parallel connection is a lot less problematic than series.A 5Ah cell and =
a 10Ah in series ---the 5 Ah cell winds up being charged in reverse , durin=
g dicharge of the battery.All cars would have Nicads (steel case) if had so=
mething to do with it.I have nicads here made before War # 2  still working.
> As to the use of two in the VW's --I am all for it.My gm's here have two =
from day one.Never had any problems with them not being identical.It is pro=
bably better to go after the sickness rather than fixing the symptom.Tell h=
im to go over all connections and the starter.
>
>                                                                          =
       Hagar.
> Ps: Nicads here don't seem to mind being charged in reverse.and the will =
provide power in reverse charge.
> --
>
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