Ann-Marie

Consider the Trollbridge24. It automatically puts the 24 volt batteries in parallel for charging so you can use your existing charger. It switches to series when you start your trolling motor. A big advantage is you can also charge the 24 volt trolling battery from your 12 volt alternator when the main engine is running. This will extend trolling time and extend battery life.

THE ULTIMATE SOLUTION TO TRAILER WIRING PROBLEMS. I mounted the license plate, stop lisghts, clearance lights turn lights etc, all on a 2X4 and made a clamp that would attach it to the trailer or the stern of the boat. A flexible cord plugs into the truck. No wiring on the trailer to give problems. (May not be quite legal to include the license plate but no one ever gave me any trouble.) You hang it on the trailer or boat when going to move, take it off, roll up the cable and put it back in the truck when you arrive. No need for waterproof fixtures, no burned out bulbs from the water, no rusty connections.

Yes running in parallel is OK for unmatched batteries. To answer your earlier question about battery life, the biggest killer of batteries is over discharging. For maximum battery life they should be discharged no more than 50%. I forget the actual numbers but its something like for every 10% below 50% you cut the life in half. So a 5 year battery at 50% is a 2.5 year at 40%, 1.25 at 30%, 8 months at 20%, 4 months at 10% and 2 months fully discharging. So if you were to add your extra battery up front you could more than double the life by minimizing depth of discharge and actually save money over replacing one a number of times.

BEFORE you buy new batteries, put the old ones back and test again. If you had a bad battery connection it would give the same symptoms and just substituting batteries may have cleaned up the connection.

Yes that appears to be standard Double Pole Double Throw switch, or frequently called a DPDT switch. If you can get one with "Center Off" it can also be used to disconnect the motor. You need to purchase one that is rated for the current drawn by your trolling motor or preferably higher for maximum life. Copy the wiring exactly from the old one before removing, if you make a mistake putting them back you can blow fuses or melt wires. I found a 30 amp one HERE for about $35. But many motors draw more than 30 amps. You can get an automatic switch for about $100 that automatically switches between 12 volts for charging and when your motor is set to 12 volts, or 24 volts when the motor is set to 24 volts. They are rated for trolling motors up to 80 amps.

Not sure what you mean by a "2/12V - 12V - 24V" switch. We make an automatic "Trollbridge24" switch that will change the batteries from parallel to series. The batteries are normally in parallel so you have 12 volts going to the motor supplied by both. If you switch the motor to 24 volts, the automatic switch will put the batteries in series so both are now giving you 24 volts. If that is not what you mean, I'll need a little more information.

Agree, you CAN provide precise controls matched to the load characteristics but since those specifications are so load dependent protection is usually provided by the manufacturer IN the load, not as a separate external fuse or circuit breaker. If it is a "motor control" with only a single specific motor on the output side you are correct, they have thermal and magnetic sensors matched to the load time constants and ratings. These can detect things like locked rotor and remove power befor the target self destructs. It is rare in small boats that an individual load would have a dedicated fuse or circuit breaker that would be precise enough to protect the device from overload without considerable research and expense. In general the discussions here typically refer to a distribution bus carrying multiple loads rather than trying to match individual loads.

Thanks Team_Dougherty, couldn't have said it better. If a load is relying on a cirucuit breaker or fuse for protection it is already dead by the time the breaker trips. Keep in mind the rating applies to the lightest gauge anywhere in the circuit. If you have a heavy gauge main line that branches to a light gauge feed to an instrument, then that light gauge needs its own protection since the main one could supply enough power to melt the small wire without tripping.

You may also need a larger battery. The biggest killer of batteries is discharging too deeply. And the final blow is trying to start an engine on a dead battery, that can kill it in seconds. A larger battery will have more power remaining at the end of the day for starting an engine and the depth of discharge will not be so deep giving much longer life. If non-startng battery loads are running it down and being able to start is very important, then you can use a Combiner100 http://www.yandina.com/c100InfoR3.htm between the starting battery and a dedicated "house" battery to keep them separate automatically for discharging but allow both to charge from a single output shore power charger or from the alternator on the motor.

And it is no advantage for avoiding property taxes. CALIFORNIA WILL GET YOU.

A Trollbridge24 will let you charge your 24 volt battery from the 12 volt alternator in your motor and it also equalizes the two batteries so they discharge evenly when running 12 volt items off one battery.

Yes you can put in a larger fuse to run both. Fuses do NOT protect the instrument from failure if it draws too much current. If it draws too much current it has ALREADY failed. Fuses protect the wiring and/or the failed instrument from melting insulation and catching fire. The downside is that if the fuse blows you lose both.

And check every fastener you use to make sure it is stainless. I just about completely rebuilt one seat replacing steel fasteners with stainless. It is hard to believe that manufacturers of marine products will save a few cents but ruin their reputation making products that have no business on a boat.

It can happen that the internal battery connections to the posts are bad, a load check at a battery store will diagnose it for you. If both posts are hot it seems too much coincidence for dirty connections.

For about 60 you can get a Combiner100 to connect between the starting battery and a house battery that is on the charger. That way the starting battery will get topped off with the existing charger. You have the added benefit that when the engine is running the alternator will maintain charge on the house battery since the Combiner100 is bi-directional