statpower conflict

[hugh fellows]

Thanks Emery and Henry and everyone else who commented. I follow you
loud and clear. Installing as advised. A couple more questions .
Statpower advises not to use the existing cables going to the batteries
but to use a direct #2 to replace and also a dedicated negative to
replace the chasis which was originally used as a conductor. I
understand the latter, but it seems to me if the connections are kept
clean the existing positive cable should be OK . It does ,however, have
a 60 amp circuit breaker which might show some voltage loss. Some have
recommended 50 amp fuses in the new positive lines but I'm afraid that
also would show a voltage drop and confuse the statpowers voltage
readings when charging. Since the difference between a a full and
discharged battery is only about a half a volt, a tenth of a volt might
be a significant error. More comments please.

Thanks,
Hugh Fellows
Auburn AL

 

[emerystora]

>Thanks Emery and Henry and everyone else who commented. I follow you
>loud and clear. Installing as advised. A couple more questions .
>Statpower advises not to use the existing cables going to the batteries
>but to use a direct #2 to replace and also a dedicated negative to
>replace the chasis which was originally used as a conductor. I
>understand the latter, but it seems to me if the connections are kept
>clean the existing positive cable should be OK . It does ,however, have
>a 60 amp circuit breaker which might show some voltage loss. Some have
>recommended 50 amp fuses in the new positive lines but I'm afraid that
>also would show a voltage drop and confuse the statpowers voltage
>readings when charging. Since the difference between a a full and
>discharged battery is only about a half a volt, a tenth of a volt might
>be a significant error. More comments please.
>
>Thanks,
>Hugh Fellows
>Auburn AL

I used the same wires that my original charger had. I've had no
problems. I did use a new #4 wire from the charger to the front
(engine) battery to keep that one charged up when parked and plugged
in.

Emery Stora
77 Kingsley
Santa Fe, NM

 

[henry davis]

>Thanks Emery and Henry and everyone else who commented. I follow you
>loud and clear. Installing as advised. A couple more questions .
>Statpower advises not to use the existing cables going to the batteries
>but to use a direct #2 to replace and also a dedicated negative to
>replace the chasis which was originally used as a conductor.

Their reasons have some validity. But, the gauge wire that should be used
is a function of the distance between the battery and the charger. There
are circumstances under which you would need 4/0 wire to hook up the
charger (get a long enough distance and you'll need the big gauge). There's
very little magical about the TrueCharge aside from the automatic voltage
monitoring function. It puts out 40 amps max. Size your connection wire
accordingly and you'll be safe. There may be advantages to using the large
size wire for the monitoring functions.

>I
>understand the latter, but it seems to me if the connections are kept
>clean the existing positive cable should be OK .

The existing ground can be fine too. Make certain that it's clean. That's a
tall order given the multiple connections through aluminum on the GMC
frame. I installed a 1/0 wire for the inverter so that gets used now for
ground in my case. Likewise, the positive wire provides a convenient way of
getting a very low resistance connection for the 12V. I did run my
TrueCharge for 1 year using the coach ground and the 12V wiring that was in
place. The gauges were acceptable to me according to standard wires tables.
SInce I'm trying to get more out of my battery system, I no longer use the
standard tables in the usual manner. I go up a gauge on the "marine table
for use in engine environments". Still I have a lot of original wire in the
coach.

> It does ,however, have
>a 60 amp circuit breaker which might show some voltage loss. Some have
>recommended 50 amp fuses in the new positive lines but I'm afraid that
>also would show a voltage drop and confuse the statpowers voltage
>readings when charging.

Not a problem that I can tell. You do want to fuse the wires close to the
battery as a safety item.

>Since the difference between a a full and
>discharged battery is only about a half a volt, a tenth of a volt might
>be a significant error. More comments please.

At 70 degrees F you have close to 0.8V span. But your point is still well
taken. Take the time to clean everything completely. It's a pain in the
rear but I think that it's well worth the effort.

Henry

 

[travism]

> There's
> very little magical about the TrueCharge aside from the automatic voltage
> monitoring function. It puts out 40 amps max. Size your connection wire
> accordingly and you'll be safe. There may be advantages to using the large
> size wire for the monitoring functions.

Does the Statpower have provisions to break out the sense lines? Most better
industrial power supplies do. If so, one could obviate the need for the
larger conductors.

Travis

 

[henry davis]

> > There's
> > very little magical about the TrueCharge aside from the automatic voltage
> > monitoring function. It puts out 40 amps max. Size your connection wire
> > accordingly and you'll be safe. There may be advantages to using the large
> > size wire for the monitoring functions.
>
>Does the Statpower have provisions to break out the sense lines? Most better
>industrial power supplies do. If so, one could obviate the need for the
>larger conductors.

Unfortunately it doesn't. I considered modifying the TrueCharge to break
out the sense lines but when I went to the inverter I just tapped those
bigger lines instead. I have no idea how big of a chop job it would be to
split the sense line out.

Henry