newby needs help...recharging dual batteries

[AttheDocktors]

Here's another newby question:

I am finally taking my boat out and need to recharge the dual batteries. My boat has two interstate 24M RD cranking batteries and is also equipped with a dual battery switch. My two questions are:

1. When recharging do I need to set the battery switch to any particular setting? It's in the off position. Will recharging one automatically recharge the other?

2. I read on the internet that batteries need to be filled with water. How do I know if I need to do this and how do I accomplish?

Any help would be great.

 

[Silvertip]

Re: newby needs help...recharging dual batteries

Yes -- batteries need to be full of water. Use distilled water only. Some maintenance free batteries have removable caps and some don't. If you can get the caps off (six on each battery), look into the cell. If the top of the plates are showing -- add water.

As for charging, how are you charging them? Separate portable charger, on-board charger, or ????. If its an on-board charger (permanently installed in the boat), just plug it in. If its a portable charger you need to charge each battery separately. The battery switch is used when running. BAT 1 charges BAT 1 and all accessories run off BAT 1. BAT 2 setting functions the same as BAT 1 except for BAT 2. BOTH means both batteries are being charged and all accessories are powered by both batteries.

 

[AttheDocktors]

Re: newby needs help...recharging dual batteries

Thanks Silvertip.

I was going to initially use a schumacher speed charge smartcharger. Now that I just found out it'll be a couple of more weeks before i get it out (need to replace the the bellows) I was thinking of using the shore power line since I have the time.

Here's a few more if you don't mind:
If I were to use the smartcharger - do I need to remove the batteries from the boat?

To clarify - you stated "BOTH means both batteries are being charged" Whether using shore power cord or speedcharger, should I change the switch to BOTH while charging?

Thanks again

 

[Silvertip]

Re: newby needs help...recharging dual batteries

The description I gave you for the battery switch is when the engine is running and the batteries are being charged by the engine alternator. No -- you do not need to remove the batteries from the boat to charge them. Remember, they are being charged by the engine when running and they are obviously in the boat so there is no difference here. You should be able to set the battery switch to BOTH and connect your portable charger to either battery and both should charge. HOWEVER -- people have done some creative wiring with battery switches so to be safe, leave the switch in the OFF position and charge each battery separately.