Dual battery system

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Has anyone attempted or installed a dual battery system to run lighting and other farkles? I have been toying with this idea for a while, but haven't attempted it yet..
 
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Dave.David

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Has anyone attempted or installed a dual battery system to run lighting and other farkles? I have been toying with this idea for a while, but haven't attempted it yet..
I'm told all the police ST 1300 add a extra battery. I was thinking about wiring in one of those small jumper packs , the cell phone size jumpers. And maybe just having it hardwired into the system
 

Byron

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Re: Ddual battery system

What are you running on an ST1300 that the standard battery won't handle? Heated accessories probably use the most power but if you work out your circuits the factory battery should do pretty well as long as you don't try running everything at once.
 

T_C

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Re: Ddual battery system

I wonder why we don;t have a two in one battery. Have this built into a lithium battery pack. Once voltage drops down to a minimum level it cuts off the supply. But there is a reserve capacity to start the bike. You'll have to push a switch or something to restore the connection.
 
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Re: Ddual battery system

You aren't really running power accessories just off the battery. If your charging system (alternator) doesn't have enough capacity for your loads it won't be long before the battery/batteries are discharged.
The battery should get the engine started and the charging system should maintain the system voltage.
 

ST Gui

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Re: Ddual battery system

jettawreck said:
You aren't really running power accessories just off the battery. If your charging system (alternator) doesn't have enough capacity for your loads it won't be long before the battery/batteries are discharged.
The battery should get the engine started and the charging system should maintain the system voltage.
+1 The only reason for having a second battery would be to power said farkles when the engine was off or at those times when the alternator wasn't generating sufficient current: long stop lights? Idling on the road side?

Not that I would know but I've never heard of ST1100/1300P bikes having a second battery. Is that correct? From Honda or something that local corp. yards cobble together? Around here motors usually turn off their lights on anything longer than a traffic stop and even then off during the day.

I'd like to replace the factory a more studly one but have no need for a second one. But honestly it's more work than I care to do.
 

Dave.David

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Re: Ddual battery system

+1 The only reason for having a second battery would be to power said farkles when the engine was off or at those times when the alternator wasn't generating sufficient current: long stop lights? Idling on the road side?

Not that I would know but I've never heard of ST1100/1300P bikes having a second battery. Is that correct? From Honda or something that local corp. yards cobble together? Around here motors usually turn off their lights on anything longer than a traffic stop and even then off during the day.

I'd like to replace the factory a more studly one but have no need for a second one. But honestly it's more work than I care to do.
I heard about the second battery from a Honda service department, dealership, that works on the police bikes. I want to know if there is a divacharge or not? A small lead battery or ?

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Re: Ddual battery system

I wonder why we don;t have a two in one battery. Have this built into a lithium battery pack. Once voltage drops down to a minimum level it cuts off the supply. But there is a reserve capacity to start the bike. You'll have to push a switch or something to restore the connection.
Sears Diehard batteries had that feature for a while in the 80's. It was cool, but never really worked, and was discontinued. Todays DieHard batteries are a whole different beast, back then they were made tough, I think I had the same one for over 10 years, I'd just swap it everytime I got another car, was still in my old Ford Granada when I drove it to the wreckers to retire it. Todays Diehards? Junk.
 
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I think a two battery system needs a special charger and the hookup is different - otherwise you end up charging one battery fully and the other does not receive a full charge. I'm not clear on this - I read an article on dual batteries for an RV years ago and don't remember the specifics. It stressed the need to wire the batteries properly and to be able to isolate and charge one battery at a time.
 

Dave.David

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I think a two battery system needs a special charger and the hookup is different - otherwise you end up charging one battery fully and the other does not receive a full charge. I'm not clear on this - I read an article on dual batteries for an RV years ago and don't remember the specifics. It stressed the need to wire the batteries properly and to be able to isolate and charge one battery at a time.
It's called a divacharge. It allows the charge to go to each battery without allowing the charge to connect each battery . Each battery is separated in that sense.

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T_C

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I think a two battery system needs a special charger and the hookup is different - otherwise you end up charging one battery fully and the other does not receive a full charge. I'm not clear on this - I read an article on dual batteries for an RV years ago and don't remember the specifics. It stressed the need to wire the batteries properly and to be able to isolate and charge one battery at a time.
AKA - battery isolation circuit

Alternator can charge both but when thd engine is shut off you only draw from one. The other is reserved for starting the engine. Quite common in RV's and limousines.
 

Dave.David

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AKA - battery isolation circuit

Alternator can charge both but when thd engine is shut off you only draw from one. The other is reserved for starting the engine. Quite common in RV's and limousines.
Thank you. I'm sure I am spelling divacharge wrong and I think it's a brand name of who makes the battery isolation circuit. That is the same thing I was talking about.

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It's called a divacharge. It allows the charge to go to each battery without allowing the charge to connect each battery . Each battery is separated in that sense.

Sent from my SAMSUNG-SM-G935A using Tapatalk
AKA - battery isolation circuit

Alternator can charge both but when thd engine is shut off you only draw from one. The other is reserved for starting the engine. Quite common in RV's and limousines.
You guys got it! I didn't remember the specifics, never having owned an RV or boat w/ dual batteries. Thanks. But it means one more component should someone put two batteries on a bike.
 

T_C

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Thank you. I'm sure I am spelling divacharge wrong and I think it's a brand name of who makes the battery isolation circuit. That is the same thing I was talking about.
Yeah, not sure of brand names either. Lot's of them out there. Does give the potential benefit of using different types of batteries. Deep-cycle for when runnign off the battery while using starting battery for motor starting. But in the limited confines of the ST... a moot point.
 

ST Gui

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AKA - battery isolation circuit
These were really popular in the heyday of monster car audio systems. That was my introduction to those circuits (but I didn't have Hi-Po audio).

Still the only reason I'd want another battery is to help start the bike and I'd rather shoehorn a bigger battery into the bike. Maybe a small gel battery to power LED flasher arrays with the engine off to spare the bike battery? Charging it might be a problem. Maybe remove it and charge it off of AC then replace it in the bike?

Except for some kind of special application or need I think a second battery mod would have little return for the effort.
 
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Re: Ddual battery system

A great use would be if you have to have a CPAP and go camping. You could run one down and still start the bike in the morning!
I think we have a few threads on this. The issue iirc was a large enough battery to run the cpap without depleting the battery life vs battery taking up storage space.

OP there are a few solutions for this under the heading of battery isolator.
-Drop in battery isolator.
-Marine 1,2,both switch.
-Beefy schottky diode to charge the house/aux battery.
-Relay triggered by engine run to charge the house battery.
-Purpose made IC control like an LTC4412 controlling a MOSFET Essentially an "ideal" diode with a low voltage drop.
You'd in some form short out the isolation in the case of a no start so the aux battery helps start the engine.

None of that would help that much with loads bigger than the alternator capacity.
 
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