Rigging a second battery

[jimcr]

I think I will just add another battery and charger, sounds like it would be so much easier because both Motors have charging systems.

Guys good luck , let us know how it comes out. I have to figure out mine and still put an hour meter on the kicker.

[diesel]

Me personally......I would put the 2 batteries in parallel. After a day of running the riggers up and down and powering all of the electronics, it puts a lot of drain on the battery.

How long will a battery last that is continuously deep drained and recharged?

roughly 70 cycles then the battery is junk. this goes for all batteries not just deep cycle

i would strongly recommend like mike siad running the batteries in parelall this is done by going pos to pos neg to neg.

[1mainiac]

Not to pick on Dan but there is no actual number of cycles 70 to 100 is probably average but that is for smaller batteries that are seldom well maintained. For example a forklift battery can last for decades and they are run down and recharged daily. The biggest issue is most people have no idea what a cycle is and often go way past dead. Depending on cell type a battery is dead at roughly 10.6 volts however it will continue to work well past that voltage but becomes damaged as the damage accumulates they go dead faster and faster and the owner complains that he bought junk. I work on 12v systems all day every day and see guys who take care of their stuff get many happy years out of the same batteries other people consider junk.

[Ashman]

Okay I have a question for you guys.

My boat has the switch that says "off"..."1"....."Both"...."2".

It is the dead of winter and I want to put the battery charger on to get the batteries up.

When hooking up the battery charger, should the switch be set to "Both" so they both charge?

[Nailer]

Okay I have a question for you guys.

My boat has the switch that says "off"..."1"....."Both"...."2".

It is the dead of winter and I want to put the battery charger on to get the batteries up.

When hooking up the battery charger, should the switch be set to "Both" so they both charge?

To do it properly the switch should be set to off, then charge the batteries separately. I have been told that if you have two batteries hooked in parallel that only the first battery will charge properly. That is why they make 1,2,3, bank chargers.

[1mainiac]

I guess it would depend on the size of the charger and the duration of the charge. What works best is a nice long soak. The one issue with charging multiple batteries is getting all the cells correctly charged which requires a equalization charge very few modern chargers say they do that anymore because it can be hard on AGM and Gell cell batteries. To be honest the only time you should charge batteries as a bank is if they are all identical batteries the reason is because you can have a dead cell in a bank of batteries and never know it. each cell can vary between 1.7 dead and 2.3 fully charged so it is possible to have 5 fully charged cells and 1 dead one and still have the battery read 13.2vdc which would seem like a decent battery till you try and put a load on it and then it will fall on it's butt.

[mj6131]

Don't have it installed yet, but I have an isolator relay: the second battery is cut out while you are cranking, then when the cranking battery reaches some voltage, I believe it's 13.7, the relay closes, and allows the alternator to charge the second battery. It also has a 1,2,off switch, and I believe the 2 position cranks from the second battery, but since the other battery is a distance from the main, and I only ran 6 ga. wire to it, I think I'll avoid that setting. It will be nice to have the off position for when I leave things on.

[floorboy]

I bought one of these from Calumet Marine.

http://www.bepmarine.com/home-mainmenu-8/product-278/716-sq-100avsr-dual-battery-charging-cluster

Works terrific. Isolates the trolling batteries. And combines them in case of an emergency. It also flips over when the starting battery is full and charges the trolling batteries.