David Lee Two Stick

[gene]

The best way to fix this is to replace your soon-to-fail diode isolator
with a COMBINER....

This way all you have to do is start the engine and the batteries are
combined and the alternator is charging both.

An additional feature is if your alternator fails, just run the Onan with
the house charger and the combiner works again to get you home with out the
alternator....

such a deal

gene

>> PS the boost will not do any good as you need to 'charge' the rear
>> battery with the alternator. Dean
>
>In my GM finshed coach when I excercise the boost switch it puts all
>batteries, good and questionable in the same circuit.
>
>I recall once when my house battery was bad and I wanted to start my
>Onan, I used two long dowels, using one to push the Onan start switch and
>the other to push the battery boost switch on the dash. This worked and
>enabled me to start the Onan which then recharged my House/Onan
>battery.(after a long time running!)
>
>Does anyone understand what I just said? Hmmmn?
>
> David Lee Greenberg
> GMC Motorhome Registry
>Dedicated to the preservation of the Classic GMC
> http://www.gmcss.com/registry.htm
>
gene fisher 76 PB/OR/CA
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/

 

[gene]

can't remember if I sent you this reference or not but I have page that
shows how the combiner replaces the diode isolator

http://www.california.com/~eagle/batt.htm

se sure to read the other references there also.

gene

>
>This way all you have to do is start the engine and the batteries are
>combined and the alternator is charging both. >>>
>
>Gene,
>I'm not sure what your definition of COMBINER is - I assume it is some type
>of heavy-duty relay between the battery sets that will connect the batteries
>when either side gets a charge. I would add my enthusiastic vote to replace
>the isolators with a combiner.
>
>In our truck sleeper business, we used isolators at one time. The inherent
>voltage drop across the diodes meant we had to modify alternators and
>converter/chargers to compensate for this - or put up with constantly
>under-charged batteries (not good).
>
>After testing several relay combinations, I settled on the Sure Power 1315,
>which they call a Battery Separator (I prefer the term "separator" myself).
>This is their two-way version, which will connect the battery sets if either
>one is being charged. For details see:
>http://www.surepower.com/separator.html.
>
>Sure Power provides options for a remote switch to allow manual connection
of
>the battery sets (for emergency starting purposes), but we do not use this
>option. In a truck, it is very important not to drain the engine battery -
if
>the truck won't go the man's income stops, too. Usually it will be the house
>battery that gets drained first, and with a manual override switch it would
>be too easy to switch in the truck battery, and end up with a dead truck.
>
>We always connect the gen-set starter to the truck batteries. If the house
>batteries are down, the customer can still start the gen-set.
>
>We have had very good success with these separators.
>
>If you do use some type of relay to connect batteries, I would suggest that
>you occasionally check for pitted contacts by measuring voltage drop across
>the contacts when the batteries are being charged.
>
>That's how we do it.
>
>Erv Troyer
>Lagrange, IN
>
>PS: Tomorrow morning we fly to San Francisco to pick up our first GMC. I'm
>taking a laptop, and if I can get a connection (and have time) I'll keep you
>posted.
>
>Yes, the Black List is going along, and NorCal Gmc in San Rafael will check
>it out before we start back.
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/