2 battery setup

[Lars H]

I just purchased my 26M Wind Dancer. It came with a 2 battery setup. Traditionally, is the one on the left side (facing aft) of the compartment the starter engine and the right one house?
Anyone have suggestions for a simple efficient charger?
Much appreciated!
Larry

[Stickinthemud57]

I have been very happy with my NOCO Genius 2-battery charger: https://no.co/genius2x2

They have single-battery chargers too if you prefer.

[Jimmyt]

I just purchased my 26M Wind Dancer. It came with a 2 battery setup. Traditionally, is the one on the left side (facing aft) of the compartment the starter engine and the right one house?

Larry,

In my boat it is. But, my wiring uses an off, 1, 2, both switch, with all loads served by the battery selected. So, it doesn’t really matter. Having said that, I do have a better deep cycle battery in my designated “house” spot.

[kingtoros]

Welcome! I think I saw the posting for your boat, well done!

I take the batteries off the boat in the off season and keep them on individual battery tender jr https://a.co/d/0RveTig

My battery well is like Jimmyt described, here's a photo. 2005

[dlandersson]

I'm very happy with my Perko switch set up.
Having said that, I also have the NOCO (kids keep running car batteries down) and I can (sadly) vouch that they work pretty well.
I also have a Noco Genius GB40 for jump starting a boat battery - just in case. Never needed it - yet.

I have been very happy with my NOCO Genius 2-battery charger: https://no.co/genius2x2

They have single-battery chargers too if you prefer.

[Starscream]

I just purchased my 26M Wind Dancer. It came with a 2 battery setup. Traditionally, is the one on the left side (facing aft) of the compartment the starter engine and the right one house?
Anyone have suggestions for a simple efficient charger?
Much appreciated!
Larry

I don't think that there was any standard setup; most dual-battery setups were installed post-sale by either a dealer or an owner. You can determine which is battery 1 on the selector and which is battery 2 by using a voltmeter and cycling a load on and off and watching for a voltage variation.

Most likey both batteries are "dual purpose" batteries, but this will be marked on the battery. Dual purpose means they have good Cold-Cranking amperage and can be used to start a motor, and also reasonable "deep discharge" ability for use as a house battery. If both are dual-purpose and have the same capacity, you can choose which is your house and which is your starter and it doesn't matter which is which.

I've found that the best charging setup for me is a single-bank charger connected to one battery, with an ACR (automatic charging relay) connecting the two batteries together. This way, you cannot forget to charge a battery regardless of the selector position: both batteries will charge from a single source using the ACR at any time that a charging voltage is present from any source on either battery. In the future, the ACR will allow you to simply add solar to both batteries by connecting a solar charge controller to one battery.

Minn-Kota has a nice line of single and dual bank marine chargers that are very well built, and not terribly expensive. Easy to source on Amazon or even directly from the Minn-Kota website.

[OverEasy]

Hi LarsH!

Like the others have done we modified Over Easy to a dual battery system with a twist.
To help make the batteries last longer we have two Perko switches.
Both have Off/battery-1/battery-2/All positions to select.
Our twist is one Perko is our USE selector and the second is our CHARGEselector.
This way we can have one battery in use for the daily activities while the other battery is separately charging.

It’s the same system we’ve used on our RV trailer for decades.
In that original setup by Afla Gold the onboard charger would charge both batteries at the same time.
Even when brand new no two batteries are perfectly equal… one is always slightly weaker/stronger than the other.
Electricity though will always run more to the lower resistance and gradually cook that battery.
That cooking results in more electrolyte boil off and sulfadation of that battery vs the other when charging both at the same time.
This shortens battery life considerably in my experience backed up by the battery replacement rate under that arrangement.

We changed out to the dual Perko Use/Charge arrangement and found our batteries were lasting YEARS longer with the same brand/size/amperage batteries. The 5 year batteries were lasting 3+ additional years whereas with the prior system they were lucky to get 3-to-5 years of use before crapping out. Our separate Use/Charge system literally saved us hundreds of dollar$.

Also, With the separate Use/Charge system the depleted battery recovers charge faster (at the same charge rate) than trying to charge two batteries at the same time.

Note 1: We’ve previously looked at several dual battery “smart” chargers but while they may perform as advertised they require both batteries to be “ON” at the same time… this could potentially result in the inadvertent depletion of both batteries at the same time if the charger goes off-line or when disconnected from shore power while out and about on the water. This could potentially lead to a situation here you are unable to start the engine…. In our current setup either of our batteries are sufficient to act as a start battery with the other always held in reserve.

Note 2: We use two marine grade dual purpose start/deep cycle lead acid batteries with identical manufacturer/ratings that we bought new with the same date codes. We now have over three years of extensive seasonal use on these batteries without issue. This aligns with our decades of RV use of deep cycle lead acid batteries with the same setup.

Hope this might be helpful…

Best Regards,
Over Easy

[krum]

Over Easy,
Would you mind posting a wiring diagram, trying to visualize the connections is making my head spin. Is it possible by error that you turn on use as well as charge on the same battery? Therefore my request for a wiring diagram. Thanks for your contribution.

[OverEasy]

Hi Krum!

Good question!
Yes one could choose to set both of the switches to “All” while on shore power if one wanted to do that.
In our setup that was done as a deliberate option should we ever find ourselves with two partially depleted batteries so that we could possibly get enough current with both if either was separately insufficient. It’s always good to have options when you might need them. (While it is technically possible to hand crank an Suzuki DF60AV with a rope, some fiddling and some real hutzpah I’ll take the option of trying to nurse an electric start over the hand start )

I believe I posted the diagram previously but I’ll try to look it up and post it here in this thread.

Best Regards,
Over Easy

[krum]

Found your previous post after some searching, just what I was looking for. Thanks

[Lars H]

Thanks all for your sage advice and suggestions for chargers!
The 2 battery setup in Wind Dancer WAS added by the dealer as park of his Super Sport package. It has a Blue Sea Systems
SI-ARC Automatic Charging Relay with Start Isolation. It doesn't have an A B selector on the power switch but basically automatically combined batteries when charging and isolates them for use (LED light is on while combined), There is temporary isolation of house loads from engine circuit during starting to protect sensitive electronics. After comments about reduced battery life, I'm now thinking this is not the best setup longer term. I'm still trying to understand exactly what happens when I turn on a cabin light, but maybe my fancy multi meter can shine some light so to speak. My boat has been getting it's professional barrier coat and antifouling paint (with a red flag coat) as it's never been in the salt, having lived its previously live in Nebraska. I'm delivering it to my new marina in South Portland ME tomorrow where I will attempt to raise the mast for the first time. In prep I have been watching hours of YouTube videos and taking careful notes. Will hopefully splash this weekend. Wish me luck
Larry

[Starscream]

Thanks all for your sage advice and suggestions for chargers!
The 2 battery setup in Wind Dancer WAS added by the dealer as park of his Super Sport package. It has a Blue Sea Systems
SI-ARC Automatic Charging Relay with Start Isolation. It doesn't have an A B selector on the power switch but basically automatically combined batteries when charging and isolates them for use (LED light is on while combined), There is temporary isolation of house loads from engine circuit during starting to protect sensitive electronics. After comments about reduced battery life, I'm now thinking this is not the best setup longer term. I'm still trying to understand exactly what happens when I turn on a cabin light, but maybe my fancy multi meter can shine some light so to speak. My boat has been getting it's professional barrier coat and antifouling paint (with a red flag coat) as it's never been in the salt, having lived its previously live in Nebraska. I'm delivering it to my new marina in South Portland ME tomorrow where I will attempt to raise the mast for the first time. In prep I have been watching hours of YouTube videos and taking careful notes. Will hopefully splash this weekend. Wish me luck
Larry

Based on this description, my guess is that one battery is wired to the motor, and the other to the house loads. Easy to find out which is which, just measure voltage on each battery with everything OFF, then switch on all the lights: the battery that shows a slight voltage drop is your house battery. If the lights aren't enough to vary the voltage, leave 'em on for a few hours so that the battery discharges a bit.

The only other possibility is that both batteries are combined via the ACR and both batteries are in parallel acting as one big combined house/starter battery. I just don't see any logic in doing it this way because house loads could then cause a no-start motor condition.

Good luck!

[ris]

We ran our boat 26X for 8 years and 13,000 miles on four 6volt Trojan 105s wired up as two 12 volt batteries. The batteries were wired together so the 4 six volts produced 12 volts with 450 amp hours. The house and cranking were the same batteries. We still have 2 of the six volt Trojans as the starting battery and a new 200 amp hour LiFePo4 battery. The motor (Honda 60) will charge the house battery, and the solar panel (175 watt Flexible) will charge the lithium battery. The charger (Sterling Power) can charge each one but only one at a time. We also have a battery to battery (DC to DC) charger that will let the motor charge the motor battery and then the battery to battery charger will charge the lithium when the motor is running. The two 6 volt Trojan 105s gives us 225 amp hours of which we can use 112 amp hours + the 200 amp hours of lithium = 312 amp hrs of power for the house bank

[Lars H]

I chose a Battery Tender Jr and slept on my boat for the first time while still on the trailer. It seemed to function well and maybe less chance of "cooking" one battery? Based on the pamphlet in the stack of documents I was gifted I thought both batteries were linked together during charging either one. I started with the port side until the light turned green. Then I hooked up the starboard one which wasn't lighting up "green". After a few hours (I fell asleep) it took turned green, so maybe the ACR was switched out but not the Switch? Actually glad to potential get longer life. Thanks again everyone!
Boat now in the slip!