Adding a 2nd battery question.

[Chris142]

I would like to add a 2nd battery to our 2013 can am Maverick off road toy.. The stock battery is a LB -20 size. I currantly have a 310 CCA Deka agm in it. It does call for an agm type

I know you are supposed to buy batteries as a pair.

But my currant battery is still good. I have room under the seat for a smaller motorcycle type of battery.

What happens if I add a new smaller battery and keep my 2 year old Deka?

Will it cook one and undercharge the other since they would be different sizes and one is already 2 years old?

 

[Jetronic]

No, the one that is discharged more will accept more current, and the one that's charged more will accept less.

But the one that has the longest leads on it is most likely to be undercharged/underused.

Make sure both batteries are the same technology though.

 

[The_Jeff]

What are you trying to accomplish, more power for a winch? More starting power?

Odds are stacked against you with it being a different size and age. Maybe put a marine switch on it so you charge it during "good charging times" then isolate it until you need it.

 

[4wd]

What are you trying to accomplish, more power for a winch? More starting power?

Odds are stacked against you with it being a different size and age. Maybe put a marine switch on it so you charge it during "good charging times" then isolate it until you need it.

If adding a Perko switch - may as well toss in a few bucks for the dual battery condition gauge - pretty cheap anyway …

 

[Cujet]

Probably work just fine.

 

[cptbarkey]

Why bother putting them in series? I run winches with a jump pack. Easy peasy.

 

[Chris142]

What are you trying to accomplish, more power for a winch? More starting power?

More starting power. The machine is known to have starting problems . Pretty unnerving to be miles from somewhere and it barely cranks enough to start.

 

[JohnnyG]

Why bother putting them in series? I run winches with a jump pack. Easy peasy.

What do you mean? If you wire them in series, you'll end up with a 24 volt system. All kinds of bad stuff will result.

 

[Donald]

If adding a Perko switch - may as well toss in a few bucks for the dual battery condition gauge - pretty cheap anyway …

There are battery isolators and battery combiners

The battery isolator separates the charging of the batteries by silicon diodes. So there will be 0.7V drop. Not the worst but not great either.

A battery combiner put the batteries in parallel when it sees alternator charging voltage.

But both of these solutions are for boats where you have a starting battery and a house battery and want the engine alternator to charge both but in most cases the battery load is still pulled from the respective battery (starting or house).

Obviously a battery switch with a 1 or 2 or both could do what you want. But manual.

My pickup has two batteries. In parallel all the time.

 

[4wd]

There are battery isolators and battery combiners

The battery isolator separates the charging of the batteries by silicon diodes. So there will be 0.7V drop. Not the worst but not great either.

A battery combiner put the batteries in parallel when it sees alternator charging voltage.

But both of these solutions are for boats where you have a starting battery and a house battery and want the engine alternator to charge both but in most cases the battery load is still pulled from the respective battery (starting or house).

Obviously a battery switch with a 1 or 2 or both could do what you want. But manual.

My pickup has two batteries. In parallel all the time.

Yep, have owned several boats and diesel LT’s … Trucks with aftermarket duals for winches etc …
He needs to select one or the other if they are different …
Me? I would get a single upgrade …

 

[f355spider]

More starting power. The machine is known to have starting problems . Pretty unnerving to be miles from somewhere and it barely cranks enough to start.

Has anyone on the forums for this product diagnosed the issue with the starting problem? If it is power related, is the starting switch contacts getting dirty? (clean them or replace the switch) Is the starting relay contact bad? (replace it) Maybe improve the circuit with heavier cables or add a relay by the starter and run cables directly off the battery? I kinda feel the additional battery is simply a bandaid for your problem.

 

[Chris142]

Has anyone on the forums for this product diagnosed the issue with the starting problem? If it is power related, is the starting switch contacts getting dirty? (clean them or replace the switch) Is the starting relay contact bad? (replace it) Maybe improve the circuit with heavier cables or add a relay by the starter and run cables directly off the battery? I kinda feel the additional battery is simply a bandaid for your problem.

Imo the stock 310cca battery is not enough to start a 2 cylinder 1000cc engine with 11-1 compression.

 

[repairman54]

310 CCA battery cranks both my 3 cyl. 1200cc Ski Doo's in winter cold just fine. A little slower in sub zero temps but they start.

 

[meep]

I think I’d wire a combiner which automatically fires in once running to charge both, and disconnect at key off, and then a manual side to combine if needed while “doing a thing.” Easy with a SPDT switch to set to one mode or the other. You can get around the V drop involved with isolators. Or just use a marine switch. They work.

 

[JHZR2]

They do odd things for boats. A starter battery and a hotel battery for example. They make switches to isolate various ways and combine in others.