rookie question about batteries

[TEutis]

It's time to replace the batteries in my boat and I'm trying to figure out which way to go. Right now it has two Farm & Fleet marine batteries that are cranking batteries. I'm assuming I need to go with one dedicated cranking battery and then a deep cell battery for sitting in the cove listening to the radio. I should mention I have an elaborate stereo system with two amps and I don't fish so there isn't a trolling motor. My question is how to wire in the new batteries. Right now both batteries go to a Perko switch and I can select 1, 2, or both. Do I simply make sure my stereo is wired into #2 and the starter is wired to #1? If I'm selected to #1 on the Perko switch when running the engine will the deep cell battery still charge? Just looking for a little guidance here. Thank you for taking the time to get me in the right direction. I forgot to mention I do not keep my boat in a slip and I don't have power capabilities where it is parked.

 

[palace]

Re: rookie question about batteries

There are lots of threads on battery set up and some good diagrams. First you want to try to always replace both batteries so they are about the same age. Also you should match your battery series 24, 27 so forth. Yes you can get just starter bat and deep cell for your radio and accessories. Sounds like you should just keep wiring as is with the perko. Your #2 battery will not charge if the switch is set to 1. Generally most alternators will not charge a deep cell. Deep cells are designed to be discharged to about 80%, then charge with a battery charger. I picked up a nice Schumacher charger/starter at Sams Club for $39. Batteries are good deal at Sams as well. Also checkout bluesea's website, good information. I you are sure your alternator has a built in regulator switch and amp output then compare to your batteries if you want to try and charge both while running the engine. Unless you are running the engine for awhile (30 min plus) you are really are not going to get much of a charge to a deep cell. Oh yeah deep sea website will give explanation on how to calculate how long your battery will last when running your acessories.

 

[TEutis]

Re: rookie question about batteries

thanks for the info palace - can you expand a little more on the battery series? Thanks.

 

[NYBo]

Re: rookie question about batteries

Sorry, palace, but your reply has some incorrect information. The two batteries don't have to be the same age or size series, and an alternator will charge a deep cycle battery just as well as it will charge a starting battery with a slight caveat: you will likely not be running the engine (and therefore the alternator) long enough to fully charge the deep cycle battery if you run it way down. That is where a charger comes in, as you noted. Be sure both batteries are fully charged right after each trip to get the maximum lifespan out of them.

 

[TEutis]

Re: rookie question about batteries

Okay, someone is right and someone is wrong - lol. I'm siding with Bob since he seems to be the more experienced of the two. Can someone explain the series - 24, 27, etc. Thanks.

 

[NYBo]

Re: rookie question about batteries

The series numbers refer to standardized case sizes, with a larger number indicating a larger size. It is usually a good idea to buy the largest size that will fit. Larger size=larger capacity (all else being equal), and no one ever complained about having too much juice. Too little, on the other hand...

BTW, palace has some good info in his reply, and you would be wise to heed it. After re-reading it, I think part of my "disagreement" has to do with some info he implied but didn't state. For example, you can have problems if you leave your battery switch in the "Both" position with the engine off and mismatched batteries. The weaker one will draw down the stronger so they are equal.