trickle charger for both batteries or just one?

I'm thinking of buying a trickle charger to save the life of my batteries. Do I need to buy two charges if I have an Isolator? If I only need one, which battery do I hook it up to?

Here is an informative charging thread. I ended up buying the Battery Tender chargers. But to answer your question you will need 2 chargers.

http://www.wakeworld.com/MB/Discus/messages/3183/207754.html

Clint:

Can you explain a bit more what you mean by "save the life of the batteries"???

Are you talking about something to keep the batteries charged all winter, or something from weekend to weekend?

Buying a cheap trickle charger and slapping it on the battery for several months could have the exact opposite effect of what you want. While a trickle charger won't drive much current they often have no regulation and can slowly overcharge the battery.

If you want a trickle charger for the winter then I would recommend putting it on a 7 day timer and set it to come on just one day out of 7. Unless there is a significant draw from the boat's electrical system that should be more than enough to keep the battery fully charged.

If you need something weekend to weekend then I would highly recommend getting a "smart" charger. It doesn't necessarially have to be a full "multi-stage" charger but you want something that will drive some reasonable amount of current until the battery reaches full charge and then backs the charge level down to a "float" level. A good float charger will keep the battery at about 13 volts.

If you have two batteries that are isolated then you would need either two chargers or a charger with two outputs. Alternatively, you could connect the two batteries together while they were on the charger (just be sure to disconnect them before use).

If the real problem is that you have some circuit that is running the battery down between weekends then your best bet would be to disconnect the battery. A boat I had a few years ago had bilge pumps that automatically cycled on every few minutes. For a week or two it was no problem, but a month of this would seriously drain the battery. I added a battery switch to shut everything off while the boat sat on the trailer and didn't have any more problems.

Rod

Rod,

Let me get this straight. Are you saying that you can trickle charge two batteries if they are in parallel???

I have two batteries piggy backed, and I just hook up the main battery to the trickle charger. I thought that once the main battery was charged the current would just move over to the second battery.

Cliff.... I'd suggest you look into the following. http://www.basspro.com/servlet/catalog.TextId?hvarTextId=45195&hvarDept=000&hvarC lassCode=0&hvarSubCode=0&hvarTarget=browse&cmid=PP _P2_1&cmCat=CROSSSELL. I'm in the process of installing one of these in my boat for this summer. I bought the XPS 5/5 to charge my two Optimas when the boat is not being used. This type of charger will also send different amounts of voltage to your batteries depending on what shape each is in, and then go into float mode when the batteries are charged.

I have multiple batteries separated by a Hellroaring isolator, if I put my charger on the starting battery, when it reaches full charge, the isolator opens up and allows the second battery bank to charge. So, it depends on what kind of isolator you have whether you need two chargers or not.