Rookie with a battery question

[Soilordirt]

I've just bought a 2007 Lowe 165 from a guy with very few hours on it. Great boat and we love it! But today our trolling motor ran down and I'm trying to figure out the problem. Seller said it had an onboard charger, but I can't find it! Where would it be on this boat as it is not near the batteries? Also, I noted it has 2 - 24v batteries but when I put a charger on each, the voltage was near 12 volts in each battery. Is this a common practice?

Thanks for any help anyone can offer!

 

[fhhuber]

On board charger for the trolling motor should be near the batteries. The way it works is... you plug it into the house. There should be a 3 prong plug somewhere, typically near the cables connecting the engine to the boat.

Note: Bringing a 24 V nominal battery down to 12V is VERY BAD. Don't do that.

 

[Old Ironmaker]

A 24V system takes 2 X 12V batteries ran in tandem, not 2X 24V, that would be 48 volts, I have never heard of a 48 V electric troller. And yes the onboard charger should be very close to the 2X12 V batteries. If not look where your starting 12V battery is or a compartment close by.

 

[bruceb58]

You likely are not using a 24V battery. You likely have 2 12V batteries in series.

 

[fhhuber]

Probably not 24v batteries...
true.

However the things exist and I've seen it done. (but not with an on-board charger)

And there are 48v trolling motors...
http://www.iboats.com/Minn-Kota-E-D...895223--session_id.960419031--view_id.1450683

Not too common yet.

 

[Old Ironmaker]

Probably not 24v batteries...
true.

However the things exist and I've seen it done. (but not with an on-board charger)

And there are 48v trolling motors...
http://www.iboats.com/Minn-Kota-E-D...895223--**********.960419031--view_id.1450683

Not too common yet.

Well you learn something everyday and that is a good thing. That 2 HP Minn-Kota electric is $3000.00 or $1500.00 per Horse Power. Would it need 4 batteries I wonder? Not to derail this thread but how many pounds thrust would that be? PM me if you wish and have an answer.

 

[fishin98]

He might have a ACR wired into the system and called it a onboard charger. Start at the batteries and follow the wires, if there is a ON BOARD charger you will find it, usually close to the batteries, or mounted under something to protect it from the elements.

 

[bruceb58]

He can't use an ACR to charge both batteries in series...only one of them.

 

[Soilordirt]

Guys, thanks for the info! Big mistake I made was reading the top of the battery which says 24DC. However, in smaller print that was obscured is the info that I really needed, 12V! So, I've got 2-12V batteries and not the 2-24V batteries that I thought I had! Other issue is that I don't see the onboard charger and can't find it. I called the previous owner this morning and he said he thought it had one, but just routinely charged the trolling battery before he went out. I suspect now that it doesn't have it and used it so infrequently that his home charging took care of it.

 

[U-LUSA]

This is what it says at www.batteriesnorthwest.com about the voltage reading you should be getting from your battery.

A fully charged battery will give you the best and longest service. Be sure the batteries are fully charged before testing or using your R..Vs. A fully charged battery, without a drain or load, after the surface charge has dissipated, is 12.63 volts for a 12 volt battery. Other states of charge are: 12.60 volts = 93% charged 12.55 volts = 89% charged 12.50 volts = 85% charged 12.45 volts = 80 % charged 12.18 volts = 50 % charged.

I always use a specific gravity tester. The manager at Interstate Batteries told me that is the most accurate way to test a battery.

 

[bruceb58]

An onboard charge is technically a home charger. It plugs into 110V.