Variety of Battery Questions

[lorisuemiller]

My husband and I just bought our first boat, and I've been looking for information about batteries on the internet. I'm finding some mixed reports.

Our tritoon currently has two cranking batteries installed with a Perko switch with 1 | 2 | All | Off. It has a 12V trolling motor, GPS/fishfinder, stereo, etc. I'm reading that you shouldn't use a cranking battery for a trolling motor. When we went for a test ride, one of the batteries was dead, so the previous owner switched to the other, and the motor started right up.

It sounds like a trolling motor should be run off a deep cycle or at least a dual purpose battery. Is it common to have two different types of batteries (deep cycle + cranking) in a switched situation like this? I hear that dual purpose batteries can handle starting and trolling motor or other electrical devices. Is that the better way to go? We want to install an onboard charger, too. I think I saw that some of you have the ProMariner onboard charger. Is that what you would recommend?

One other question . . . I also saw references to Blue Sea ACR. Does that serve the same purpose as the Perko switch? If not, can someone summarize its purpose?

We suspect that we might have to replace the batteries or at least correct this situation. What do you think? Appreciate any advice.

[PlaynDoc]

i use the Minn Kota MK 220D for my two deep cycle 'house' batteries - trolling motor, wash down pump, etc.
i use the Minn Kota MK 106D for my cranking battery.

I SHOULD have went with the Minn Kota 330 D instead, so one charger would do all 3....

If you have only 2 batteries, the Minn Kota 220D should do you just fine...

I have no idea what the Blue Sea ACR is....

[jafo9]

you appear to have a pretty common setup. perko is a brand name like xerox. however most people who don't know this just tend to call any marine battery switch a "perko" switch. your current setup does exactly what you described. the boat and alternator either "see" battery 1, battery 2, or a combined 1+2. the off position is nice as it isolates both batteries from any parasitic loss during extended storage. whatever the boat "sees" is what the boat draws power from and what it charges. an ACR is a different animal. basically with an ACR and a voltage regulator the boat can "see" multiple batteries depending on the charge/voltage situation. i'll use my pontoon as an example. it has the blue seas ACR that came with their Add a Battery kit. i have a start battery and a house battery. the start battery is the typical marine start battery and the house is a deep cycle battery. my pontoon has a 12v fridge so it has a higher than normal battery draw. this may be similar to your situation where you have a trolling motor. unless the batteries are both over a certain voltage (i can't remember exact numbers off hand but something like 13.4v) they are isolated. so the boat sees the start battery and when the start battery exceeds 13.4v, it connects the 2nd battery (1+2 in your case) so it get charged. when the boat is turned off, all my electronics (radio, lights, fridge) are drawing from the house battery. as they draw, the house battery drops below the threshold voltage and the ACR isolates them. thus, i can run stuff all day and the start battery is isolated or untouched. when i crank the motor, the boat only "sees" the start battery which has a fresh unmolested charge. after the start battery reaches 13.4v the house battery is added to the mix and it gets charged off the alternator. your basic "perko" switch can do basically the same thing, but an ACR makes it automatic.

[lorisuemiller]

Thank you both for the answers. I appreciate it!