2022 Yamaha sho auxiliary house battery charger

[mvanosdale]

I have an optima battery as my cranking battery. And am installing a house lithium iconic 125ah battery for my electronics. I have just been made aware that my Yamaha sho has an auxiliary charger lead that can be purchased and installed. I just need to ask if it is okay to run my cranking battery as is and hook up the lithium house battery on the auxiliary charger? Does anyone else on here have any experience with this?

[ThomasD]

I have a '17 SHO 250 and have been using an Ionic 125a as cranking/electronics for almost 4 years now. More than enough power for both.

[mvanosdale]

I will have both the optima and the lithium. The lithium will be on the auxiliary charging harness

[yam911]

No personal experience with your specific motor and battery but I see no reason why it will not work.

I suspect you have a VF225LB model SHO. The VF225LA models did not have the isolator lead.

It would help us help you if you could add that to your SHO model.

[mvanosdale]

That is correct it’s a VF225LB

[mvanosdale]

I think I have answered my question. Looks like the isolator lead connects to the positive on the house “electronics” battery. The house “electronics” battery negative connects to the cranking battery negative as a common ground. There should be no draw between either battery this way or mixing chemistry’s etc. I will have no issue having my cranking battery as a OPTIMA and my house as an ICONIC lithium.

[yam911]

[mvanosdale]

That’s what got too

[mvanosdale]

Can anyone answer my last question… what is the reason for the cranking battery and house battery negatives being connected? That shouldn’t have any issue them being different chemistries (agm and lithium)??

[yam911]

Can anyone answer my last question… what is the reason for the cranking battery and house battery negatives being connected? That shouldn’t have any issue them being different chemistries (agm and lithium)??

The electrons that flow from the alternator via the isolator lead need a way to get back to the alternator.

That is what the ground from the house battery to the starting battery and on back to the motor does.

The current from the alternator neither knows nor cares to know to where it goes.

[mvanosdale]

The lithium and the optima sharing negative shouldn’t be an issue correct?

[yam911]

Correct.

There is no way other than to share the grounds.

Flooded lead acid. Gel lead acid. AGM lead acid. Lithium. When any two (or more) share the power supply they have to share the ground.

[mvanosdale]

Copy that.