Is it worth the money to buy and install a switch just in case the main engine starting battery ever fails to start, to switch over to one of the trolling motor batteries?
Just curious ...
Thanks in advance
God Bless

Or just carry jumper cables then you can jump off of someone elses boat also

i made a set of jumper cables just for that. used #8 wire and alligator clamps. about 10' long, reach from my trolling motor batteries to the crank battery. haven't had to use them yet, but i've got em if i need em!

A battery switch that will connect the positive terminals of your batteries is worthwhile. A jumper cable will work, but the switch eliminates clutter. You may not always have access to another boater to help you out.

Will not work because the trolling motor battery`s and the cranking battery uses a separate ground. You would have mount 2 separate switch`s. Just a suggestion keep the jumper cables in a water proof container. I don`t know how many times I have seen booster cables that look like they have been laying on the bottom of the lake. Useless.

Thanks....guess I'll look around for an inexpensive set of cables and jumbo zip lock baggie
God Bless

Why can't you connect the starting battery to the first trolling motor battery in a 24V or a 36V string? I have a 24V system and my lights and electronics are running off the positive post on the first battery which provides 12V and shares a common ground with the starting battery.

Which brings me to another question. Is there a reason to not have the starting battery and the one supplying 12V to the boat's systems on the same ground? When had a 12V TM, I installed a Blue Sea ACR and the installation diagram showed the starting and "house" battery using a common ground. That should be OK with my current system as long as it's the 12V sources sharing the ground.

Don't go too cheap. The really cheap ones have small wires and don't do so well jumping. If you've ever jumped a car with them, remember how long you had to wait for them to get enough of a charge through to crank the engine? Put a small wire brush in there to clean them for a good connection.

Seen that tryed years ago Bob and if you connect a another battery into a 24v system that jumps 24v at the battery`s it will act like a welder when you connect the cranking battery + & - to one of the trolling motor battery`s. Yes you can draw 12 volts from one battery in a 24 or 36v system.

I'm talking about connecting the start battery pos post with the pos post on the 12V battery, not the pos post that supplies 24 volts to the trolling motor.

to safely jump from a 24 volt system you need to disconnect the jumper wire from the 24 volt then hook up to one battery for the jump.

Morning, all good points but, back to original question: Is there no one who has installed or uses a 'switch' from main battery to one of the 24V TM batteries ?
Doesn't sound like it ...
God Bless