Hello.

I have a 12 volt a Deep Cycle Boat trolling motor battery I'd like to
keep charged via my chevy s10 v6 blazer. I currently have two 4 guage
wires running about 6 feet to the back of the car connecting the
primary battery to an 800watt inverter. With the engine running I can
I drill, cut wood, make popcorn and and fry fish on an electric
skillet - it's awesome.

I'd also like to charge that trolling battery as I drive around. I
know most will tell me to get a fancy isolator and connect it to all
sorts of places in the truck. WHY? Any way I can safely hook it up to
that 4 gauge wire with diodes and pull from both batteries and the
alternator when using the inverter, but never ever pull from the
trolling battery or the inverter for anything relating to the car. I
figure any small amount of current to the second battery will keep it
topped off, but any risk of loosing normal draw for starting or normal
operation of the viechle. Any chance the guys at best buy will be
able to put this simple solution for me? they originally install the
inverted and did a great job for $50. What are the risks?

Many thanks for *any* help or information.

Since you have an inverter why not just plug a 120v battery charger into it
and charge the batteries while you drive?

wrote in message
om...
Hello.

I have a 12 volt a Deep Cycle Boat trolling motor battery I'd like to
keep charged via my chevy s10 v6 blazer. I currently have two 4 guage
wires running about 6 feet to the back of the car connecting the
primary battery to an 800watt inverter. With the engine running I can
I drill, cut wood, make popcorn and and fry fish on an electric
skillet - it's awesome.

I'd also like to charge that trolling battery as I drive around. I
know most will tell me to get a fancy isolator and connect it to all
sorts of places in the truck. WHY? Any way I can safely hook it up to
that 4 gauge wire with diodes and pull from both batteries and the
alternator when using the inverter, but never ever pull from the
trolling battery or the inverter for anything relating to the car. I
figure any small amount of current to the second battery will keep it
topped off, but any risk of loosing normal draw for starting or normal
operation of the viechle. Any chance the guys at best buy will be
able to put this simple solution for me? they originally install the
inverted and did a great job for $50. What are the risks?

Many thanks for *any* help or information.

wrote in message
om...


I'd also like to charge that trolling battery as I drive around. I
know most will tell me to get a fancy isolator and connect it to all
sorts of places in the truck.

What sort of trailer light connector do you currently have?

If you have the 7 conductor round RV style connector then there is a good
chance that you are already wired for supplying 12 volts to the trailer. If
it is properly wired, the 12 volt connection should have a fuse/circuit
breaker on the vehicle.

You can simply make a new adapter that provides a 4 pin pigtail for the
trailer lights and brings out the 12v and ground to connect to the boat
battery.

You can do a lot more work to assure that you had isolation, but it probably
isn't worthwhile. Note that any diode isolation you install is going to
dramatically reduce the charging current to the boat battery.

Rod McInnis

Thanks for the response. The inverter is off unless I'm using it - and
if it wasn't it's cooling fan might drain my primary battery overnight
with the engine not running. Also, the inverter works, but inverters
are anything but efficient, alot is lost in the exchange from DC to
AC. And if left connected to a drained battery on the output side it
would attempt to charge it with a battery that is not being fed
alternator power. I'm sure it also takes alot of AC to charge DC too.

Some cars have a relay socket, so you can install a charging relay for
charging batteries in travel trailers only while the vehicle is running.
Otherwise, get a battery combiner from West Marine etc. for about $80 and
connect one end to the car circuit and the other to the trolling battery.
Bill

"Rod McInnis" wrote in message
...

wrote in message
om...


I'd also like to charge that trolling battery as I drive around. I
know most will tell me to get a fancy isolator and connect it to all
sorts of places in the truck.

What sort of trailer light connector do you currently have?

If you have the 7 conductor round RV style connector then there is a good
chance that you are already wired for supplying 12 volts to the trailer.
If
it is properly wired, the 12 volt connection should have a fuse/circuit
breaker on the vehicle.

You can simply make a new adapter that provides a 4 pin pigtail for the
trailer lights and brings out the 12v and ground to connect to the boat
battery.

You can do a lot more work to assure that you had isolation, but it
probably
isn't worthwhile. Note that any diode isolation you install is going to
dramatically reduce the charging current to the boat battery.

Rod McInnis