adding 2nd batt and charger

[trainwrecker22]

I want to add a 2nd batt to my boat. Do I absolutely need a perco or other batt switch? Also if I do install a batt switch how do I connect a charger/maintainer? Also has anyone used one of them solar chargers? As it is anyone out 250$ cheaper for a slip with out power.

 

[trainwrecker22]

Dam auto correct on my fone.

 

[UncleWillie]

What do you intend to accomplish by adding a second battery? ???
Depending on that answer, you may or may not need a battery switch or additional charger.

A solar maintainer will keep a fully charged battery full, but require weeks to actually charge a battery.
Unless you live in a desert area and have a large boat, or spend days at sea, forget the solar option.

 

[achris]

2 batteries connected in parallel will flatten each other, so yes you absolutely must have an isolation switch.

Connection is easy. The switch has 3 terminals, usually labelled something like 'Battery 1', 'Battery 2', and 'Common'. Connect each battery to each of the 'battery' terminals, run the cable from the 'Common' to the engine post. Run any accessories off the 'Common' terminal.

Chris....

 

[trainwrecker22]

I want to 2nd batt for peace of mind. I was thinking one batt for starting/deep (duel purpose) and one deep only so when I stop to fish or am just sitting at a dock somewhere I can has the radio or fish finder on and not have to worrie. If I hook up a iso switch how do I hook up a matainer/ charger or can I set it to both and charge off alternator? Sorry if this is a redundant question but I am green as **** to boating.

 

[achris]

I leave a trickle charger on my boats' batteries while I'm away (for up to 9 weeks at a time). I put the battery switch to "BOTH" and hook the charger to either battery, no problem. If you have a normal radio (not something that can be heard half way round the world :facepalm and fishfinder, a battery will keep them going for about 2 weeks, and still be able to start your engine.

 

[UncleWillie]

You will need a battery switch if you ever want to use the second battery to start the engine.
Placing the switch in BOTH while the engine is running or a shore powered battery charger is attached will charge both batteries in parallel.

There is No problem with placing batteries in parallel, they will play nice together and share the load and charge.
They will not fight and, one will not end up killing the other one. They do Not have to be a matched pair.

The Add a Battery Kit with an ACR will take all the thinking out of When to place the battery switch in What Position.
It switches automatically, and you will only need one battery charger to charge both batteries.

 

[JASinIL2006]

A poor man's solution is to just carry jumper cables to use the second battery as a back up starter battery. You'd have to keep the 2nd battery charged somehow, but cables would do in a pinch. I used to have a second battery just for a backup bilge pump; I kept the battery charged manually and had jumper cables on board.

For the record, it was enough of a pain that I recently added an Add A Battery kit (ACR and switch from Blue Seas) to keep both batteries charged and usable, but that route is more expensive than the jumper cables...