Wayne.B wrote in
:

Rolls batteries typically last 7 to 10 years if well cared for. We
are *not* talking Walmart quality here. Most of the folks who buy
those beautiful little Duffy boats are old enough that 7 to 10 years
is as good as a lifetime warranty.



Running sailboat lighting, the stereo and some electronics with the
intermittent load of the bilge pump and inverter is a far cry from
running a 20 horsepower DC propulsion motor pulling a large boat at 8
knots, discharging the hell out of the Sooperbatteries in the process.

Guessing, using the standard 846 watts/hp, 20hp = 16,920 watts divided by
the 96 volts all the series batteries produce = 176 (and change) AMPS if
you're running it at 8 knots, wide open. Wanna bet they get HOT?!

Pouring out 180 amps from a plastic cased lead-acid battery, subject to
physics and chemistry no amount of advertising hype can contradict, I
submit there's no way a Rolls sooper-dooper battery will survive 7 years
of this abuse, which amounts to connecting your Rolls house batteries to
the starter motor and driving home without diesel fuel every time you run
the boat.

I'd love to test this theory if Rolls is willing to fund the Duffy and
$14,000 worth of Rolls batteries for an honest test, however. LET THE
DEEP CYCLING BEGIN!

I see the accessories all run off yet another $900 house battery. I
didn't add that figure in because every boat has those.

The damned battery supplies from anywhere seem to go flat when someone
shows up with the simplest calculator and ohms law asking embarrassing
questions why the 4KW inverter can't run 2 ton of air conditioning off
$15,000 in batteries....(c;

On Fri, 23 Jun 2006 15:12:59 -0400, Larry wrote:

Running sailboat lighting, the stereo and some electronics with the
intermittent load of the bilge pump and inverter is a far cry from
running a 20 horsepower DC propulsion motor pulling a large boat at 8
knots, discharging the hell out of the Sooperbatteries in the process.

Guessing, using the standard 846 watts/hp, 20hp = 16,920 watts divided by
the 96 volts all the series batteries produce = 176 (and change) AMPS if
you're running it at 8 knots, wide open. Wanna bet they get HOT?!

Your numbers are off a bit. Around here these things get driven by
little old men and ladys around the canals for a few hours on Sunday
afternoon when the grand children are visiting. Average speed is
probably about 5 kts which requires no more than 3 or 4 hp with an
easily driven hull.

Figure 4,000 watts give or take, around 40 amps, no heat generated, no
animals killed, injured or abused. After 3 hours the batteries are
still at greater than 50%. These things do not get taken off shore.

:-)

On Fri, 23 Jun 2006 15:12:59 -0400, Larry wrote:

///
Guessing, using the standard 846 watts/hp, 20hp = 16,920 watts divided by
the 96 volts all the series batteries produce = 176 (and change) AMPS if
you're running it at 8 knots, wide open. Wanna bet they get HOT?!
//

Make that 746 watts per horse

Brian Whatcott Altus OK

Brian Whatcott wrote in
:

Make that 746 watts per horse


oops....anyway it's way too many amps...continuously.