Another 12V battery conversion!
Kai Knickmann (Damask
0945) from Germany looked at the options for replacing his old 6 volt batteries
and an offer from a local trader produced another 12 volt battery conversion.
Twin BOSCH 4FNs wired in parallel provide improved starting performance
and a near original look. (Photo: Kai Knickman)
Finally my good old
6V batteries died this winter despite being hooked to a trickle charger all through
the winter months and some thorough power load tries last week. Maybe ten years
were enough for those lead acid batteries. Initially I was inclined to leave the
car as original as possible, but when a local motor trader offered replacement
6 volt batteries at something in the range of 140 € (each! - that is £)
for new 6 volts, I reconsidered my options.
After browsing the V8 Register
archives on the web, especially V8 Workshop Note 329, I declined to go for one
"big" 12 volt battery like an "063" or "065" (although
the idea of a spares box in the redundant battery box was tempting!) because I
didn't like the idea of flattening the base stand with the big mallet.
Another V8BB thread started by Mike Price last October mentioned using a small
12 volt battery from a Japanese car which was a similar size to the 6 volts in
the V8 and this route seemed interesting for me, although there seemed to be a
potential clearance problem in height. In the meantime, V8 Workshop Note 330 goes
quite a long way in showing the merits and feasibility of such a single 12 volt
BOSCH offered a good choice for me with a battery
called 4FN which is geometrically identical in footprint with the old standard
6 volt ones (they are just a fraction lower than the original 6 volts which are
175 mm high), using silver technology for a longer lifetime,
to Contents listing being
service free and sealed for life and as an additional plus, having a nice black
case as well. Of course, the electrical values due to the reduced size are less
impressive with 360 amp cold start and 40Ah capacity. But after the first test
with just one unit (I was in quite a hurry!), the starter cranks the engine far
better than ever in the last four years!
In the meantime, V8 Workshop
Note 330 goes quite a long way in showing the merits and feasibility of a twin
12 volt battery solution. This leaves me with plenty of power under all circumstances,
keeps the appearance nearly original and still saves me half the cost, as one
of these small 12 volt batteries is just 70€ here in Germany. This all in
all seems to mimic a setup that Anthony DeBella in the US uses on Damask 1317
with good results according to his latest information on the V8BB.
are just minor modifications to change the electrical connections so the two
12 volt batteries are connected in "parallel". A second earth lead
strap was fabricated for the second battery similar to the original one and attached
to an earthing point already included by MG in the offside battery box side member.
Then you need another cable to link the two positive points. You might think of
using the original cable passing over the differential through the rubber hose,
but it seemed to be pretty short to me, so I routed a new longer one the same
way. At the right hand side, there are now two cables attached there to the positive
terminal - the original hot wire from the car's wiring loom and the new link cable.
Finally I need to
add that I turned the J pegs which clamp the batteries down from looking frontward
to rearward as the new batteries have a stepped upper side being pretty low on
the terminal side. As the threads on the J pegs are a little bit short now, I
used 15 mm spacers to get the nuts "higher up". Alternatively, you could
either shorten and rethread the old J pegs or use new shorter ones straightaway.
So all in all I'm
quite happy with the new layout which you can see finished on the attached picture.
You just need to be able to live with the fact that the batteries in the back
were designed to fit a FIAT Panda!