Weak generator battery

[sfedeli3]

Tom Sorrentino ('87 PT38) and I finally solved the loss of voltage
across the diode on our generator batteries with the installation of a
Battery Link ACR from Blue Sea Systems. For anyone with a mid-80's
coach that has a generator without its own alternator, Blue Bird
installed a diode to permit the on-board battery chargers to also
charge the genset battery, but keep it isolated from the house
batteries when necessary. As many of you have experienced, this
arrangement never quite allowed the genny battery to get topped off
because of the voltage loss across the diode. We installed these units
this past weekend and so far they work beautifully. I'm now seeing
14.4 volts at the genny battery and 14.4 volts at the engine batteries
in my PT when the charger is on and the ACR is in "combine" mode. Once
the charger is off and the voltage drops off to around 13.2 volts, the
two banks disconnect and remain apart until the house voltage rises
above 13.4 volts again (or I rock the Aux battery switch to "on"). The
Blue Sea unit was around $90 and is an easy "drop-in" replacement for
the diode- although we used heavier 6-ga. cable to allow more power
across the ACR. It is also a good idea to install an 80-amp resettable
breaker in line with the ACR in case there is ever a short in the
genny battery circuit.

Shane Fedeli
85PT40
Hershey, PA

[Gregory OConnor]

Shane, sounds like a good device for my three bank system. Is the
blueSea able to pass 79 amps? Or return pass the request amps of a
failed start using aux "combined"??? the mfg calls it a charging
link. recharging a genset battery should draw no more than 20 amps.
with a good starter the momentary "combined" to start should not be
needed. I would think 79 amps would cook the BlueSea and the only
time there would be a big cross would be using aux to make a start
of gen or the detroit with compramised starters. I now use mini
alligator clips and 14 ga wire to charge my add on genset battery
and have no issue unless I drain the battery when boondocking by not
unclipping a clip. I think charging and starter issues begin with
overuse of momentary aux "combined"????

a link to Shanes find:

http://www.nulime.com/Blue-Sea-7600-CL-S...CR/p237402

or

http://tinyurl.com/5aeaer


GregoryO'Connor
94ptRomolandCa



--- In WanderlodgeForum@yahoogroups.com, "sfedeli3" <sfedeli3@...>
wrote:
>
> Tom Sorrentino ('87 PT38) and I finally solved the loss of voltage
> across the diode on our generator batteries with the installation
of a
> Battery Link ACR from Blue Sea Systems. For anyone with a mid-80's
> coach that has a generator without its own alternator, Blue Bird
> installed a diode to permit the on-board battery chargers to also
> charge the genset battery, but keep it isolated from the house
> batteries when necessary. As many of you have experienced, this
> arrangement never quite allowed the genny battery to get topped off
> because of the voltage loss across the diode. We installed these
units
> this past weekend and so far they work beautifully. I'm now seeing
> 14.4 volts at the genny battery and 14.4 volts at the engine
batteries
> in my PT when the charger is on and the ACR is in "combine" mode.
Once
> the charger is off and the voltage drops off to around 13.2 volts,
the
> two banks disconnect and remain apart until the house voltage rises
> above 13.4 volts again (or I rock the Aux battery switch to "on").
The
> Blue Sea unit was around $90 and is an easy "drop-in" replacement
for
> the diode- although we used heavier 6-ga. cable to allow more power
> across the ACR. It is also a good idea to install an 80-amp
resettable
> breaker in line with the ACR in case there is ever a short in the
> genny battery circuit.
>
> Shane Fedeli
> 85PT40
> Hershey, PA
>

[sfedeli3]

Hi Greg,

I put an 80 amp resettable marine grade circuit breaker in the
charging compartment with the ACR (Automatic Charging Relay)to prevent
it from ever getting cooked. Although it has an internal self-limiting
protective element, the only way that I could forsee that happening
would be if the batteries were all linked and you hit the genny start
switch or main engine start while you had extremely low voltage in one
bank. The only time that the two banks become linked on my coach is
when there is a charge over 13.4 volts- but that can be adjusted up to
14 volts. Since it is designed for marine use on an alternator-charged
system- the presence of plug-in shore power (as opposed to genset or
alternator power) presents a new dynamic that should/can be addressed
with the resettable breaker.

Since we never fried the old diode (which only had 10 ga. wires in
my coach), I'm guessing that there are very few situations where the
call for power across the ACR would exceed 80 amps. Also, in response
to your question about a 3-bank system, the unit is designed to work
on only two banks, so I would connect it to your house and genset
banks only. The main engine bank can easily get a charge directly from
the on-board inverter/charger. Most of them already have an extra
connection for a second bank of batteries.

Shane Fedeli
85PT40
Hershey, PA

--- In WanderlodgeForum@yahoogroups.com, "Gregory OConnor"
wrote:
>
> Shane, sounds like a good device for my three bank system. Is the
> blueSea able to pass 79 amps? Or return pass the request amps of a
> failed start using aux "combined"??? the mfg calls it a charging
> link. recharging a genset battery should draw no more than 20 amps.
> with a good starter the momentary "combined" to start should not be
> needed. I would think 79 amps would cook the BlueSea and the only
> time there would be a big cross would be using aux to make a start
> of gen or the detroit with compramised starters. I now use mini
> alligator clips and 14 ga wire to charge my add on genset battery
> and have no issue unless I drain the battery when boondocking by not
> unclipping a clip. I think charging and starter issues begin with
> overuse of momentary aux "combined"????
>
> a link to Shanes find:
>
> http://www.nulime.com/Blue-Sea-7600-CL-S...CR/p237402
>
> or
>
> http://tinyurl.com/5aeaer
>
>
> GregoryO'Connor
> 94ptRomolandCa
>