Battery Tender

[Cole Sanger]

So I want to put a battery charger on the new system. From advise on here I will be going with the following:
1 Perko Switch
3 Batteries running parallel off one side of Perko
1 Starting battery off second side of Perko
Question 1. Where do I hook up a battery charger to the batteries so all will charge in storage?
Question 2. What is a good battery charger for the above question?

[WET HULL]

I am using the Cascade APS-75 for my system. This one will allow you to jump into a generator someday if you wanted. Mine has the positive wire out of the power supply hooked to the common side on the perko so it can charge both batteries at the same time. The ground is hooked up to one of the battery ground terminals. Thats all it takes.

[thmper321]

Just leave the perko switched to both if you want to charge all the batteries at the same time. I guess you could leave the perko switched to off but use jumper cables to tie the batteries all together. It would be the same as having the perko set to both but with no chance of accidently starting the boat.

[Cole Sanger]

I was doing some reading last night and I thought I would have to get a two bank charger. I have read a little about the APS-75, but aren't those pretty expensive? Anyone have a recommendation for a two bank charger other than the APS-75?

[Sotally Tober]

I'm using the APS 75 for the same type of batt system. It is ran to the common on my perko. I have 1 Optima for my starting batt (#1 on Perko), 3 Trojans for my amps (#2 on Perko). My starter is attached to the common also. When I plug in I switch the perko to what I want to charge. Usually just #2. I only use the APS to charge the trojans to save my alt. When I unplug to go out I switch the perko to #1. When I start it pulls from the optima and only charged it. I can just switch to "all" if I need to. Works great for me. I can easily add a gen if I need to. But I haven't. Good luck.
Just remember that most 2 bank chargers will put out 10-15 amps per bank, this could take days to charge up 3 drained batteries.

[Cole Sanger]

Since I use my boat once a week, I went with the Guest 2611A dual bank charger. I don't think I will really drain my batteries too much, so this small charger should do just fine. It will have a week to charge the batteries. I got it over at Skipper-dan.com for $82.95 with free overnight shipping.

[Sotally Tober]

Sounds good. How many amps does it put out?

[Cole Sanger]

It's pretty small. It only puts out 5 amps per bank. Like I said, I have a whole week between trips, so hopefully it will work out. If not, I can upgrade bigger if needed.

[Cole Sanger]

Just a quick question...
Will I run into problems if I parallel two batteries for starting and three batteries parallel for the stereo will I? I have never paralleled a battery before. Thanks

[Sotally Tober]

No problem, but why. It will give you more cranking amps. You can parellel as many batteries as you want. Now when you run them in series you will start changing voltages=bad. 1 starting battery should be plenty.

[Cole Sanger]

The only reason is that I currently have 2 batteries. One on perko side one and the other on side two. I just ordered three optimas for the stereo. I hear that it is bad to mismatch batteries. I figured I would just take the two I currently have and parallel them for the boat and it's electronics.

[phebus]

The only reason is that I currently have 2 batteries. One on perko side one and the other on side two. I just ordered three optimas for the stereo. I hear that it is bad to mismatch batteries. I figured I would just take the two I currently have and parallel them for the boat and it's electronics.
I'd save the weight, the cable, and the battery box, and just use one of your existing batteries. No sense using something just for the sake of using something. Also, your alternator is going to take a beating trying to charge all those batteries.

[Cole Sanger]

I wakeboard a lot. I need all the weight I can get. Just bought three fat sacks for weight. The altenator should be ok for just two batteries. I was thinking about adding a high output altenator down the road.

[Sotally Tober]

You could just charge your stereo batts with the plug in charger as I do. My alt. only charges the starting batt. I do not want to start burning up alternaters. I have gone all weekend and never gotten below 12v. Just plug in when I'm done. Make sure you go with the group 31 Optimas. They have more reserve amp/hours.

[Cole Sanger]

That is my plan also. I went with the D31M Optima's. They say 155 reserve capacity. Just found out that Jegs has them on backorder though.

[Sotally Tober]

The D31M is what I'm running for my starting Batt. My 3 trojans have a reserve capacity of 225 each.

[Cole Sanger]

Wow, how much do those run?

[Sotally Tober]

I paid 149 for the Optima and 103 for each trojanSCS225 (http://www.trojan-battery.com/Products/ProductSpec.aspx?Name=SCS225) .

[Cole Sanger]

Looks like I was wrong, I looked again and the D31M has 210 reserve at 25amps. Where did you get those optima's? I bought from Jegs, but they haven't shipped (backordered). I am paying 189.99 each. I would love to cancel them and order somewhere else. Thanks

[Cole Sanger]

bump

[Sotally Tober]

Bought at my local Standard Battery store.

[Sotally Tober]

Looks like I was wrong, I looked again and the D31M has 210 reserve at 25amps.
Where are you getting 210? This (http://www.optimabatteries.com/publish/optima/americas0/en/config/product_info/marine/technical_specs.html) shows 155 if I'm reading it right.

[Cole Sanger]

I got the 210 because I am retarded. I opened the pdf file from their site that shows the recharge time at 25 amps. Like I said, retarded.