Hello Boaters.

Anybody got this set up? An aux battery is charged by the boat's
engine, but is isolated so that it will only be used in emergency or
by another circuit like for an 800 watt invertor? And while the boat
is sitting for two months, solar energy is maintaining both batteries?

Sounds nice huh? Possible?

Anybody got a working and proven solution and would be so kind as to
share products/vendors and a high level design ?

Many thanks again - you guys are great!

I've got a separate battery bank that is dedicated to a small inverter. Runs a
laptop computer, small TV etc, when anchored out. It's a great idea, and really
extends the life of the house bank between
recharges.

But I'm in the Pacific NW. What's solar energy? :-)

If you put two battery banks on one solar charger, you'll probably need some
sort of diodes or what not to keep the battery with the lesser charge from
attempting to equalize with the more highly charged battery- a circuit might be
completed through the internal wiring of the charge unit itself. Any time two
batteries are connected to the same circuit they can't be considered isolated.

When you say sitting for 2 months, do you mean there is no electrical drain?
If so, as far as I know, there's nothing needs doing ... the battery's will
hold their charge ... or enough to get you going again. As for a deep
cycle/starting battery setup, I charge my deep cycle trolling battery while
underway by simply attaching what we call up here jumper cables (they're
usually in the back of the jeep through the winter, so why not put them to
use over the summer I thought) and I disconnect when trolling.

OT: Although I suppose a $120 diode isolator would make that complex and
difficult task a lot easier. And would provide me with an excuse to use my
cell phone when I go to start up, and find I've got 2 dead batteries. Hmm
.... but if I bought a coupla voltmeters to watch ... or designed and built
an automatic cutoff at say 11.5 volts ... nah ... life's too short, I'll
stick with the jumper cables..

wrote in message
m...
Hello Boaters.

Anybody got this set up? An aux battery is charged by the boat's
engine, but is isolated so that it will only be used in emergency or
by another circuit like for an 800 watt invertor? And while the boat
is sitting for two months, solar energy is maintaining both batteries?

Sounds nice huh? Possible?

Anybody got a working and proven solution and would be so kind as to
share products/vendors and a high level design ?

Many thanks again - you guys are great!

wrote in message
m...
Hello Boaters.

Anybody got this set up? An aux battery is charged by the boat's
engine, but is isolated so that it will only be used in emergency or
by another circuit like for an 800 watt invertor? And while the boat
is sitting for two months, solar energy is maintaining both batteries?

Sounds nice huh? Possible?

Anybody got a working and proven solution and would be so kind as to
share products/vendors and a high level design ?

Many thanks again - you guys are great!

Use two 5 watt solar panels and a continuous duty isolator relay. It can't
get any simpler than that.
Jim

".JIMinMA." wrote in message ...
Use two 5 watt solar panels and a continuous duty isolator relay. It can't
get any simpler than that.
Jim

Okay sounds good. The isolator would connect to what other than the
two batteries? And it's purpose would be to keep anything on the boat
from pulling from the aux right? Also, would 5watts overcharge the
batteries and require a controller?

Yes, the batteries would have no load while sitting, but I'm recalling
those two week trips and my car not starting when I got back.

Thanks!

wrote in message
m...
".JIMinMA." wrote in message
...
Use two 5 watt solar panels and a continuous duty isolator relay. It
can't
get any simpler than that.
Jim

Okay sounds good. The isolator would connect to what other than the
two batteries? And it's purpose would be to keep anything on the boat
from pulling from the aux right? Also, would 5watts overcharge the
batteries and require a controller?

Yes, the batteries would have no load while sitting, but I'm recalling
those two week trips and my car not starting when I got back.

Thanks!
The relay would be turned on by the ignition switch. You could add an
isolator relay delay and make the installation a little more sophisticated.
Don't worry about overcharging. Look at the Intellitec web site for details
on the products I mentioned, and others.
Jim

".JIMinMA." wrote in message
...

wrote in message
m...
".JIMinMA." wrote in message
...
Use two 5 watt solar panels and a continuous duty isolator relay. It
can't
get any simpler than that.
Jim

Okay sounds good. The isolator would connect to what other than the
two batteries? And it's purpose would be to keep anything on the boat
from pulling from the aux right? Also, would 5watts overcharge the
batteries and require a controller?

Yes, the batteries would have no load while sitting, but I'm recalling
those two week trips and my car not starting when I got back.

Thanks!
The relay would be turned on by the ignition switch. You could add an
isolator relay delay and make the installation a little more
sophisticated.
Don't worry about overcharging. Look at the Intellitec web site for
details
on the products I mentioned, and others.
Jim



What you want is a battery combiner not an isolator. $80 at West Marine.
When one battery goes above 13.4V (charging) the relay combines the 2
batteries. Less voltage drop than an isolator.
Bill

"Calif Bill" wrote in message
link.net...

".JIMinMA." wrote in message
...

wrote in message
m...
".JIMinMA." wrote in message
...
Use two 5 watt solar panels and a continuous duty isolator relay. It
can't
get any simpler than that.
Jim

Okay sounds good. The isolator would connect to what other than the
two batteries? And it's purpose would be to keep anything on the boat
from pulling from the aux right? Also, would 5watts overcharge the
batteries and require a controller?

Yes, the batteries would have no load while sitting, but I'm recalling
those two week trips and my car not starting when I got back.

Thanks!
The relay would be turned on by the ignition switch. You could add an
isolator relay delay and make the installation a little more
sophisticated.
Don't worry about overcharging. Look at the Intellitec web site for
details
on the products I mentioned, and others.
Jim



What you want is a battery combiner not an isolator. $80 at West Marine.
When one battery goes above 13.4V (charging) the relay combines the 2
batteries. Less voltage drop than an isolator.
Bill


They are kind of similar devices, Bill. Relay isolators do not have the .7V
voltage drop that the diode isolators do. Also the isolator relay delay has
a nice delay feature that the West unit doesn't have, which allows the
engine to start on the starting battery before the auxiliary battery is
combined with it.
Jim

If starting, the voltage will be below 13.4V and the batteries will not be
combined. I installed one on my boat as the electronics power cycled when
starting the motor (351W inboard). They happily stay on now. The only
isolators I have seen have been the diode units. The combiner is a relay.
Bill

".JIMinMA." wrote in message
...

"Calif Bill" wrote in message
link.net...

".JIMinMA." wrote in message
...

wrote in message
m...
".JIMinMA." wrote in message
...
Use two 5 watt solar panels and a continuous duty isolator relay.
It
can't
get any simpler than that.
Jim

Okay sounds good. The isolator would connect to what other than the
two batteries? And it's purpose would be to keep anything on the
boat
from pulling from the aux right? Also, would 5watts overcharge the
batteries and require a controller?

Yes, the batteries would have no load while sitting, but I'm
recalling
those two week trips and my car not starting when I got back.

Thanks!
The relay would be turned on by the ignition switch. You could add an
isolator relay delay and make the installation a little more
sophisticated.
Don't worry about overcharging. Look at the Intellitec web site for
details
on the products I mentioned, and others.
Jim



What you want is a battery combiner not an isolator. $80 at West
Marine.
When one battery goes above 13.4V (charging) the relay combines the 2
batteries. Less voltage drop than an isolator.
Bill


They are kind of similar devices, Bill. Relay isolators do not have the
..7V
voltage drop that the diode isolators do. Also the isolator relay delay
has
a nice delay feature that the West unit doesn't have, which allows the
engine to start on the starting battery before the auxiliary battery is
combined with it.
Jim

"Calif Bill" wrote in message
link.net...
If starting, the voltage will be below 13.4V and the batteries will not be
combined. I installed one on my boat as the electronics power cycled when
starting the motor (351W inboard). They happily stay on now. The only
isolators I have seen have been the diode units. The combiner is a relay.
Bill
Your right. I didn't think of that. Battery voltage typically goes to about
10 V when the engine is cranking so the West Combiner/Isolator would be in
Isolation mode. How do you handle an emergency start situation when the
starting battery is dead?
Jim