Using two trolling batteries to extend trolling life

[Chief2]

I recently bought a small jon boat, and will be using it electric only on local lakes. I am interested in extending my trolling capability by installing a second marine battery.

If I understand correctly, I can connect these two batteries in 'series', doubling amp capacity by connecting 'pos to pos' and 'neg to neg'.

Is that correct?

 

[redbug]

is that is correct but there are a few things to remember.
the bayyeries need to be around the same age or the old battery will draw down the newer battery
and they need to be the same size or you will have the same result.
be sure to use a heavy gauge jumper wire so that it doesn't overheat

 

[2sac]

Your terminology is incorrect. You would connect them in parallel. Series, which would be + to - is for a 24v application.

 

[redbug]

Your terminology is incorrect. You would connect them in parallel. Series, which would be + to - is for a 24v application.

oops missed that

 

[Chief2]

Gotcha! Thanks, guys. =D>

 

[JMichael]

It seems to me that using a selector switch and running the batteries individually would eliminate a lot of the potential issues of running them in parallel. It would also afford you the ability to know when you were at the half way point on your power reserves.

 

[2sac]

It seems to me that using a selector switch and running the batteries individually would eliminate a lot of the potential issues of running them in parallel. It would also afford you the ability to know when you were at the half way point on your power reserves.

Just my opinion, If you add a switch, you've added another failure point. Eventualy the contacts are going to wear out or corrode and cause overheating. There is a potential of 50 amps going thru that switch. I had a meltdown once from a worn out plug and receptacle at the bowmount.

 

[krawler]

I have two 12 volt trolling motors on my boat and have two batteries but use a switch so I only use one battery at a time. I use the voltage reading on my fish finder to know when to switch over.

 

[JMichael]

Just my opinion, If you add a switch, you've added another failure point. Eventualy the contacts are going to wear out or corrode and cause overheating. There is a potential of 50 amps going thru that switch. I had a meltdown once from a worn out plug and receptacle at the bowmount.

We deal with switches every day of our lives. They're pretty simple devices that have stood up to the test of time. As long as the proper switch is used for the application it's used in, they will give years and years of trouble free service with a very low percentage failure rate. And the voltage and amperage that they carry won't mater as long as the switch is built to handle it. However, batteries are known to have a somewhat short lifespan by comparison. And when one goes bad, it will drag the other one down with it if they are hardwired together in parallel. And I don't see what the meltdown of a plug has to do with this.

 

[2sac]

Just my opinion, If you add a switch, you've added another failure point. Eventualy the contacts are going to wear out or corrode and cause overheating. There is a potential of 50 amps going thru that switch. I had a meltdown once from a worn out plug and receptacle at the bowmount.

We deal with switches every day of our lives. They're pretty simple devices that have stood up to the test of time. As long as the proper switch is used for the application it's used in, they will give years and years of trouble free service with a very low percentage failure rate. And the voltage and amperage that they carry won't mater as long as the switch is built to handle it. However, batteries are known to have a somewhat short lifespan by comparison. And when one goes bad, it will drag the other one down with it if they are hardwired together in parallel. And I don't see what the meltdown of a plug has to do with this.

Maybe I'm coming at this from the wrong frame of mind. I'm a commercial hvac/r tech by trade and have been working with electricity for the better part of 15 years. I see equipment with electrical failures all the time. Anything that breaks the circuit is a potential problem. I have also been a boat owner for around the same amount of time. The meltdown of a plug has to do with this because it is a weak point or a break in the circuit. A switch is a mechanical part. Eventually it will fail. Whether it takes 5 minutes or 50 years. It's going to fail. We are not talking small amounts of current like a lightbulb. 50-60 amps which many of todays motors are rated at is no small potatos. The less breaks in the path of electricity the better. I know these changeover switches are designed for this application. I was just stating my opinion. Nothing more, nothing less

 

[nlester]

Just my opinion, If you add a switch, you've added another failure point. Eventualy the contacts are going to wear out or corrode and cause overheating. There is a potential of 50 amps going thru that switch. I had a meltdown once from a worn out plug and receptacle at the bowmount.

Where were your cicuit breakers located? I like the circuit breakers that attach to the battery with a bus bar. It seems to me that the less distance from the circuit breaker to the battery, the less the risk. With batteries in parallel, I like the idea of having a circuit breaker on each battery.

What is you goal with the two batteries? Being on the water longer or having a higher trolling speed for a longer period of time. This makes a difference between choosing pararrel or one battery at a time. Pararrel maintains your speed for a longer period of time but leaves you with nothing in reserve and requires that you replace both batteries at the same time.

 

[JMichael]

Yes, moving parts are going to fail sooner or later if they keep moving. However, it's not like we're talking about some continuous duty cycle bearings that are spinning 24/7. And the manufacture specs for these switches is

For use with 12, 24 and 32 Volt Marine Electrical Systems
Capacity - 250 AMPS Continuous, 360 AMPS Intermittent

so they stand a pretty good chance of being able to handle the 50/60 amps you mentioned.

 

[2sac]

Just my opinion, If you add a switch, you've added another failure point. Eventualy the contacts are going to wear out or corrode and cause overheating. There is a potential of 50 amps going thru that switch. I had a meltdown once from a worn out plug and receptacle at the bowmount.

Where were your cicuit breakers located? I like the circuit breakers that attach to the battery with a bus bar. It seems to me that the less distance from the circuit breaker to the battery, the less the risk. With batteries in parallel, I like the idea of having a circuit breaker on each battery.

.

Circuit breaker was at the battery. It was damaged as well and had to be replaced.