Battery Help
 

I am ready to start the rigging for the battery(s) and was looking for some help. I will be running two batteries, one for starting and one for accessories (1500W Stereo), which type of batteries should I buy? One deep cycle marine starting battery and one "regular" battery? Also, when wiring what is the best/easiest way to be sure that I don't drain the engine starting battery and isolate the two? My thoughts are that I should get a Perko 2 battery switch, where I can switch from Off, Batt1, Batt2, and both. If this is the case, should I just tap the positive terminal to the stereo battery directly? What about effective grounds, should both batteries be grounded together for a better ground or should I keep them separate? What size wires should I use for this project? I am running 4 ga power wire to the stereo and am guessing 2 gauge for the batteries? And yes, I am upgrading the stock alternator to a 100amp unit. Any further suggestions?

You have it ok. I would go with a Starter battery for the "starting" and a Gel battery for the other side. You can go with a Optima for the best bang for the buck or if you want the best with out cost considerations go with the large Stinger battery. Make sure if you ever charge Gels with a charger you read the directions about that so you do not ruin the battery. You should run a ground btwn the two battery's yes. Make sure you use TINNED wire on everything to avoid issues with Corrosion. The Perko switch will work fine. You just switch it to the off posision to listen to the stereo. When you start ONLY go to the start battery then swich over to BOTH, NOT to the other battery. If you just go the the deep cycle you will put a much added load on the alternator and could cook it.

Jon

Jon,
Thanks for the info. I was curious whether I should use a cranking battery for the engine and a deep cycle for the stereo...now I think I have it all figured out!!! Thanks for your help and I'm looking forward to finally being on the water in hopefully less than a week! I pick up the boat on Friday!!!

Thanks again,
Dave

Dave-
Good to hear your boat is getting so close! Hope to see you on the Mississippi yet this season- look for the white and purple 28' AT. We are out of Savanna nearly every weekend.:)
Jim

Jim,
We're hoping to be up and running by the end of the day on Saturday the 10th and maybe even out for a little while on the 11th if everything is put back together in time. I'm sure we will make it to Savanna sometime yet this season...it may be for just a fall color run, but hopefully we can get over there and meet up with you!

Jon,
I was looking at the Perko switches and one has a field disconnect and the other one does not. I'm guessing the field disconnect is better as that one will permit you to switch the batteries while the motor is running correct? I'm not sure if I will know of a time where I will need to do that, but for the extra $5 it sounds like it's worth it. What do you think? Thanks for your help!!!!

Dave

You DEFINATLY want the one with the field disconnect. You need to have it maintain contact as you swap from one battery to the other. You will use it all the time. For example you run your house batter (stereo) down all the way. You then swap to your starting battery to get ya started. Then you swap it back to Both for a while to get yourself charged up, then after a short period on Both you can swap to the House battery 100 percent to get yourself charged. As I stated earlier you do not want to put the alnernators on a dead battery if you can avoid it. It can cause the alternator to blow. So the both posision helps out with that.

Jon