How to configure bank charger

[85Lund]

Hello All,

I am going to start a new thread because I have specific question about my specific motor and setting up batteries and a charger.

I have an '85 Lund Tyee with an '85 Mercury 115 hp outboard. I currently have a cranking battery in the back that runs my lights and starts my motor. I have a deep cycle battery up front that runs only my troller. I need to replace the cranking battery and would like to set up a bank charger so I don't have to charge them individually. I would like some advice on how to set this up. I am clueless as to how to configure this. I would like to run 3 batteries so I have plenty of power. I don't want to spend a ton to do it. Do I want to run my lights off the cranking battery? I fish a lot at night and they seem to drain my cranking battery. Do I want 2 deep cycles and one cranking battery or 2 cranking and one deep cell? If you have had good luck with one type of bank charger or the other please let me know as well. Does this motor even charge the cranking battery? Any thought, experiences, knowledge or advice would be greatly appreciated.

It's getting close to Walleye time!!

Thanks,

 

[Chris1956]

Re: How to configure bank charger

I would recommend 2 deep cycle batteries to run lights and trolling motor. Connect them to the trolling motor and lights with two battery switches, so you can use either battery to run either the troller or lights or both. Have the starting battery dedicated to starting that inline six motor, no battery switch is needed.

To charge them: The best way is to use two battery combiners between the starting battery and between the deep cycle batteries. That way the outboard will charge them when it has some available juice, without any outboard wiring changes, and the charger may be connected to any of the batteries, and will charge them all, in whatever order you want.

 

[85Lund]

Re: How to configure bank charger

Chris,

Thanks for taking time to help me with this I really appreciate it. I apologize for my lack of knowledge here. Can you explain to me in more detail how I need the batteries wired up? I'm confused on how to get the 2 deep cycles on the switch you are talking about. After setting up the batteries, I do need a 3 bank charger right? Is there any tricks to how I need things hooked up with that?

Thanks,

 

[Chris1956]

Re: How to configure bank charger

I think the optimum solution is one that you do not need to ever manually change, unless a battery goes dead. Standard battery switches will have two battery connections and one output, and be labeled one, two, both and off.

So, wire both deep cycle batts to the two switches. I recommend you designate one battery as "battery one", and wire it to the "battery one" terminal on both switches. Repeat with Battery two.

Wire one switch to the trolling motor and the other to the lights. Now you can select which battery you want to run the troller and which one you want to run the lights. You can also run the lights on two batts, or the troller on two batts, or switch them off. For example, if you run the troller all day and the battery gets low, you can switch it to the other battery, by changing the troller switch from one to two, and turning the light switch to off.

Ok, If you have a few $$, you can make the engine charge all three batteries, and you only need to buy a single cheap battery charger. Add a battery combiner to the starting battery, and run a cable to the first deep cycle battery. When the engine charges the starting battery above +13 volts or so, it will automatically connect the deep cycle battery and charge it. Add another battery combiner from the 1st deep cycle battery to the second deep cycle battery, and that one will get charged, when the first battery hits +13V or so.

Your motor only has a 6A charging system, so do not expect miracles. But the day you get a newer outboard with a 35-40A charging system, you will be ready to charge up a storm with it.

The same charging sequence will occur with a single charger. Any kind of auto or marine battery charger will work fine. Choose the battery you want to charge first, and the other batteries "downstream" of that one will automatically charge. if you choose the starting battery, all three will charge in sequence.

 

[Silvertip]

Re: How to configure bank charger

There are a multitude of ways to set this up but the one thing that you should forget is charging the batteries from the engine. The engine alternator does not have enough output capacity to keep two batteries topped off much less three of them. You would have to run wide open for hours to accomplish that. If you separate all of the accessories from the starting battery and leave it for the sole purpose of starting the engine, you don't need a second switch. Just leave it like it is. Carry a set of jumper cables if you feel you need an extra measure of safety. You can then wire a dual battery switch as was explained. For charging at the dock, you need a three bank charger, or you can get buy with a two bank but to do that, one bank needs to connect to the start battery and the other bank to the COM terminal on the switch. The switch must be set to BOTH to charge the two deep cycle batteries with the single output of the charger.

 

[triumphrick]

Re: How to configure bank charger

I think the optimum solution is one that you do not need to ever manually change, unless a battery goes dead. Standard battery switches will have two battery connections and one output, and be labeled one, two, both and off.

So, wire both deep cycle batts to the two switches. I recommend you designate one battery as "battery one", and wire it to the "battery one" terminal on both switches. Repeat with Battery two.

Wire one switch to the trolling motor and the other to the lights. Now you can select which battery you want to run the troller and which one you want to run the lights. You can also run the lights on two batts, or the troller on two batts, or switch them off. For example, if you run the troller all day and the battery gets low, you can switch it to the other battery, by changing the troller switch from one to two, and turning the light switch to off.

Ok, If you have a few $$, you can make the engine charge all three batteries, and you only need to buy a single cheap battery charger. Add a battery combiner to the starting battery, and run a cable to the first deep cycle battery. When the engine charges the starting battery above +13 volts or so, it will automatically connect the deep cycle battery and charge it. Add another battery combiner from the 1st deep cycle battery to the second deep cycle battery, and that one will get charged, when the first battery hits +13V or so.

Your motor only has a 6A charging system, so do not expect miracles. But the day you get a newer outboard with a 35-40A charging system, you will be ready to charge up a storm with it.

The same charging sequence will occur with a single charger. Any kind of auto or marine battery charger will work fine. Choose the battery you want to charge first, and the other batteries "downstream" of that one will automatically charge. if you choose the starting battery, all three will charge in sequence.

Great Post...thanks, Chris.

 

[85Lund]

Re: How to configure bank charger

Guys,

Thanks for all of the great advise. I was under the impression that if I bought a 3 bank charger that would do what was explained above by Chris. This does not seem to be the case. I am not real concerned with charging from the motor because I rarely run it for more that 10 minutes to get to my spots on the lake in my area. I just want my cranking battery to only do one thing, start the motor. Is the switch mentioned above simply called a "battery switch"? Is it easy to install? My downfall here is that I have little to no knowledge of electricity and wiring.

Kind Regards,

(And Thanks again for taking time to help me!!)