Ok...I have a 2004 Yamaha F150 and a single group 34 blue top. The single blue cranks the motor and runs EVERYTHING else besides the Ultrex.

The battery isn't capable of running both livewells and 4 graphs through out a full day of tourney fishing.

In the owners manual, it states that the F150 has a battery isolator that has a secondary charging lead (10gauge) that capable of charging and isolating a second battery (for accessories) while keeping the cranking battery fully charged and ready to start the motor.

I have traced this wire tonight and have found it is terminated into a plug and the plug is capped. Basically it ends, going to nothing, right in front of the main motor rigging tube inside the engine housing.

Ok....the question

Can I simply solder a 10 gauge wire onto this lead and run it through to the battery/bilge area and run a second battery? Is it that easy? Or, do I need the Yamaha cable? Is there something special that might be inline with a Yamaha cable? Or, as my wife says, "it's a plug for guys that know nothing anout 12volts"...?

I have the wiring diagram for the motors charging system and it shows no diodes or such in this charging lead...it simply says "optional secondary battery charging lead" and shows how to wire in the battery and shows a 10g jumper from the negative terminal of battery one to the negative of battery two.

Any help would be appreciated.

Thanks!

Oh. It's a 2004 Skeeter TZX190 if that's important.

We have installed 2 cranking battery`s on several boats and just connect them parallel. If one battery doesn`t have enough storage to run the accessories, It still won`t on that setup.

First off....I'm glad you responded. I was hoping you'd chime in. I see you help folks a lot and you seem to really know your stuff.

I know that simply paralleling another battery would help. Just thinking that an isolated battery would benefit my situation twofold. One, I wouldn't have to buy an identical blue top battery (I have three group 31's that are good in my garage, but non match each other or the Optima ). Two, if I did drain them both, I would still be trolling my [censored] back to the ramp to jump off the batteries. Lol.

The blue top lasted about 4-1/4 hours of start and stop fishing. It is only 3 months old and very well maintained. If I added another just like it, paralleled, it would likely not make it long enough for a full 8-9 hours of fishing.

Do you think that a group 31 with 125 minutes of RC could be able to run 4 3a graphs, a LSS unit, and 4 pumps on timers for a full day of fishing?

The previous boat, an older Nitro, only had one pump for the single, divided livewell. The Skeeter has completely separate livewells with dedicated pumps for fill and recirculate.

Mondays tourney was unusual though, I had a limit of big fish within 45 minutes of launching the boat and had to use both wells all day.

Any other opinions?

I would be checking my charging system and load test that battery. Starting and stopping should help the charge. I have a habit of setting on one spot for 5 to 6 hours with everything running. When fishing a tournament 2 months ago I had fish early with high lake water temps. I would watch the voltage reading on my Humminbird 1197 and when it would get to 11.5v I would start my 175 EFI, let it build back to 13v and shut it down. Was running livewells on recirculate manual for 6 hours. I added frozen 2l bottled water. Customer of mine has a 2008 Ranger with a Merc 250 Pro XS is running a 31 Optima with a 600cca 24 Interstate, no problems going on 2 years. Called him before posting this to confirm.

Yep.

Taking home my battery checking scanner tonight. It will load test, and check the charging system at idle and under load.

Thanks again for the suggestions.

two batteries in parallel will double your run time , also double your recharge time.
why are you running four graphs at once ?
I put the console graph in standby when going to the front deck , and put the bow graph in standby when going to the console .(modern graphs use a lot of amps).
livewells have a timer, use it when you can.
I do the same as Gary when I see the main dropping to 11v or so , I fire up the big motor and charge a few minutes