# run accessories off 24V system or use aux. lawn mower batt?



## Bowhunter1661 (Jan 20, 2016)

I am having a slight bit of difficulty here.. I have a 24V Minn Kota edge for my new boat. Also have a Cabelas 2 bank 12 amp charger. I will be installing a fish finder (.8 amps), LED nav lights (.5 amps) and aerator pump (2.5 amps). I don't think it is a good idea to draw from one battery and not the other. 

This wil cause all batteries to drain sooner and at different intervals between the two. So, do I run a lawn mower battery to power these accessories? If I do I will either have to buy a new 3 bank charger, or get a portable charger to charge the other battery after every use. 

Not sure if it is a big deal to draw off only one battery or not. Please help.


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## richg99 (Jan 21, 2016)

I guess that the poor man's solution would be to wire it up so you can switch back and forth between batteries on alternate trips. 

No new battery. No new charger. Just some memory issues...which might be a problem for old folks like me, whose memory left long ago. Ha Ha 

Simple big alligator clips should do the job. Or, you could use two matching trailer light plugs. Wire the female side(s) to the batteries and move the male side back and forth on each trip.

richg99


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## onthewater102 (Jan 21, 2016)

You're talking tiny draws on the battery with more load. Yeah, on a hot summer day the aerator might draw a bit more, but if you're recharging them as soon as you get home no biggie. You're really not cycling one over the other by that much more, and chances are even if you bought them together one is at least 6 months older than the other, years different if they weren't bought together, so you can probably even up their lives by using the newer battery for the extra 12v loads.


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## RiverBottomOutdoors (Jan 21, 2016)

Won't hurt anything unless you run the batteries extremely low using your trolling motor. I will say that it's never a bad idea to isolate sensitive electronics...might be overkill...but definitely not a bad idea.


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## Bowhunter1661 (Jan 21, 2016)

Thank you very much gents. Still trying to decide on this one. I don't have a cranking battery to use unfortunately or I would hookup to that. The charger I have is still brand new. I think I may return it, get a 3 bank and use a series 24 or even smaller battery for the electronics and pumps. I spoke with 2 marinas today. Both said it was a bad idea to run those items from the trolling batteries. 

I also added up all the weight I have added this far including decks, trolling motor, batteries esc.. I have only added 280 at This point. So will another 30-40 really hurt me on the top end with my 20 HP merc? I don't really think so..


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## Bowhunter1661 (Jan 21, 2016)

I suppose I should also ask what you guys with 24 volt systems and no starting battery do about this?


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## Scott85 (Jan 21, 2016)

I have a question that relevant to this tread. Does Installing 2 batteries for a 24 volt trolling motor make the whole system 24 volts or is it still 12 volts. The reason I ask is am installing a light bar and want to make sure it still works.


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## Bowhunter1661 (Jan 21, 2016)

Scott85 said:


> I have a question that relevant to this tread. Does Installing 2 batteries for a 24 volt trolling motor make the whole system 24 volts or is it still 12 volts. The reason I ask is am installing a light bar and want to make sure it still works.
> 
> 
> Sent from my iPhone using Tapatalk


It depends if you hook your batteries in series or in parallel. Series gives you 24 volts. Parallel gives you 12 volts. It will be in series for a 24 volts system. You may be in the same boat as I. Deciding wether to hookup to one of your batteries or add a third. 

You can have a 24 volt, series system and still get 12 volts if you simply connect your positive and negative wires of the light to ONE battery. Not positive to one battery and negative to the other.


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## Scott85 (Jan 21, 2016)

Bowhunter1661 said:


> Scott85 said:
> 
> 
> > I have a question that relevant to this tread. Does Installing 2 batteries for a 24 volt trolling motor make the whole system 24 volts or is it still 12 volts. The reason I ask is am installing a light bar and want to make sure it still works.
> ...


Thank you, I've never dealt with a 24 volt system before. 


Sent from my iPhone using Tapatalk


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## Bowhunter1661 (Feb 5, 2016)

Made my decision on the battery issue. I work for an industrial forklift company and got dealer pricing on two interstate 27 deep cycle flooded batteries for the trolling motor.

Then I had to decide for the graph, live well pump and light. The guy at the counter recommended a wheel chair battery. I had 6 golf cart batteries for cores so he gave me the 35 AH AGM battery for free.

Now all I need to do it return the 2 bank charger I bought and upgrade to a 3 bank.


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## kuptii (Feb 29, 2016)

Didn't anyone suggest getting a DC-DC converter ? ... I haven't hooked up mine but I've got the same issue on a project I've started ... Depending on how many amps you pull will set the price on the unit ... Your electronics shouldn't draw much so your cost should be low AND you'll have an even draw on the joined batteries ... It's just a step down transformer or solid state facsimile ... The 'box' I picked up weighs less than a couple of pounds, rated for up to a 30 amp draw, drops 24 volts to 12 volts and cost less than $100 ... Anybody have any Pros or Cons on this ??????


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## richg99 (Feb 29, 2016)

kupti, sounds like a great solution to this problem, which I've heard about a number of times.

Do you have a LINK to one on the internet?

richg99


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## kuptii (Feb 29, 2016)

I got the box a couple of seasons ago ... long story ... so I don't remember where it came from ... Google DC-DC converters and you'll find something ...
Example of sites brought up ... https://www.theinverterstore.com


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## riverbud55 (Mar 2, 2016)

On my old ''83''Gregor bass boat it was set up with 2 batteries to run a 24v tm,, uses one of the 2 to supply house power and as a starting battery for a 75hp Suzuki,,,,some how it was able to keep the 2 batteries charged with even voltage between the two,,,,looks to me it was set up at the factory that way,,It will have a small dedicated starting battery and a mid size house battery when I finish its rebuild


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