house battery vs cranking battery, help???
 

Bought a powerquest 290 enticer last winter and still familarizing myself with all the bells and wistles, I have had a 24' baja before and familiar with the electrical system, but this twin engine is different......I have two cranking batteries and a house battery. It also has a ac/dc converter that can charge two batteries. It is hooked up to one of the cranking batteries and the house battery. The house battery appears to only be hooked up to the amp and the converter, my questions is this, shouldn't the house battery be hooked up somehow to the engines so when im going down the river with the battery switch set to "all" it will be charging both cranking batteries and the house battery??? I am not familiar with the electrical system with 3 batteries. I was thinking that i could switch to house battery when camping so i wasn't drawing from the cranking batteries but don't appear to be hooked up that way. Maybe so though, like i said still familiarizing myself with the new boat!! Any help or some info would be greatly appriciated!!

You might want to look into what is called an ACR - Automatic Charging Relay. Lots of people make them. I personally like the Blue Sea Systems brand.

My boat has a starting battery for each engine, and a two-battery house bank. The house bank is on it's own ON-OFF switch. Each engine has it's own OFF-1-2-ALL switch. I can combine each engine on both starting batteries if needed.

With the ACR, each engine is wired through the ACR to the house bank. This isolates the house batteries from feeding back to the starting batteries; however, when the starting batteries are fully charged, the ACR starts putting the charge to the house batteries.

http://www.speedcraving.com/scarab/U...-transom02.jpg

is this also called a combiner?? So this acr is really a switch, it allows the charge current to come from the alt and charge the house battery but will not pull from the cranking batteries, like a diode? one way valve??

from your description, this is exactly what i need, from what i see, there is no charging to my house battery while away from the dock or plug.. don't want it like this!! do you have to acr's ? one on each cranking battery going to the house?

Yes, the ACR is also called a combiner. They are nothing more than a relay switch that connects 2 batter'ys together using smart technology. When it sees a charge on either side, the ACR combines both batteries so that both receive a charge. When the voltage drops, as if motor shut off or battery charger turned off, the ACR opens and isolates the batteries. Works basically just like a diode but better, no voltage loss that diodes use. Today's technology, isolators (diodes) are yesterdays.

You use just 1 ACR connected between 1 start and the 1 house battery. Leave the other start battery motor sep.


Buy the Blue Seas 120A ACR battery switch kit for around $120. That 1 dual circuit switch replaces 2- 1/ 2/ OFF/Both switches.

If you just buythe ACR and keep your battery switches, don't run them in both mode. Defeats the ACR purpose.

us1, my house isn't hooked up to the battery switch at all, only the cranking batteries. So, I just need one acr coming off of one cranking battery to my one house battery. If i can see a wiring diagram i can better understand whats going on. Why would it defeet the purpose of the acr if i run my bat switch on both?? I usually run on both so both cranking batteries will charge...actually my bat switch says...1-2-all-off. Thanks for the info!!

oh...I only have 1 battery switch..

Ok, I see now, just 1 switch.
Yes, just run the ACR between 1 start and the 1 house battery. You can run in 'both' position. That will combine all 3 batteries when either/or both motors are running, then will isolate the house battery from the 2 start batteries when motors are off.

When overnighting, switch to either 1 or 2 position so as to not run down both start batteries since your cabin power is more than liky pulling off 1 of the motors. Whatever you have on the house battery, stereo amp??? will be only thing to pull off it.

What is connected to the house battery? More importantly, what do you want connected to it?

For clarification..
Do you have an Invertor/charger unit that both charges and provides AC power, or is it a 2 bank battery charger only?

Your 1/2/All/Off switch.... so both motors are connected to the common stud, with the 2 starting batteries each going to 1 and 2 studs? No way to separate the motors then.

Twin engines usually have one battery switch per engine. This gives you the ability to use either (or both) starting batteries for either motor. As US1 said, connect the ACR between the engine and house bank. In my scenario, I have one ACR per engine, so if either (or both) are running, they will charge the house bank once the starting battery has been charged. The Blue Sea ACR's have that specific circuitry built in - to only charge the house once the starting battery is up to full capacity.

See my picture above...there are two red 1-2-all-off switches, one for each engine. Then, the gray on-off switch is for the house bank to the house (stereo).

us1, for clarification, I only have one switch, and the converter/charger will power my ac accessories in the cabin as well as charge two batteries. The boat has a nice stereo and looks like only the amp is connected to it, there are some leads that power a fuse box which goes to the amp. there are only 2 fuses in it, not sure what the other fuse is powering, I really want to run all my accessories off the house battery. I might have to take some of the leads off the starting batteries and move them to the house battery when i figure out what is what. when i overnight, i only want to be pulling from the house and not either of the starting batteries. Question: I think the cranking battery for one engine, or can i crank both engines with only one battery?? Not sure how the switch is wired.

I'm still at a loss as to how you are running two engines off one battery switch. I know in the outboard world, tying the fields of two alternator charging systems together is a bad thing. I'd recommend that you install another battery switch and use the OUT of each switch to it's own motor.

Here's a diagram drawing that I did for another guy a while back. Ignore the multiple house batteries and inverter, but the rest is pertinent.

http://www.speedcraving.com/scarab/wiring_diagram.jpg

um...i can't tell you? I am still familiarizing myself with this twin engine set up. I know i only have one bat switch, two group 24 cranking batteries and one group 27 house battery. Like i said, the house battery looks like it was added just for the stereo system and the only way it is charged is by the inverter/charger which i don't want it like that. I want all of them to be tied so when my engines are running, it is charging all batteries. I never run just one engine. The engines may be able to crank with just one battery, i don't know how the switch is built inside, when it gets warmer im gonna do some investigating to see how everything is wired. Some of the accessories may be coming off one or both of the cranking batteries but i want all of it to be coming of the house battery. The inverter/charger will only charge two batteries, one is on one cranking battery and the other on the house. i will wiring them to charge both the cranking batteries, that way i know both engines will start. who knows....maybe the engines can be started off of just one of the batteries.....don't know. I can tell you this...the twin engine set up is more complex that just a single

This is what I am currently hooking up on mine now. If memory serves me right. I think I found it in a thread from US1. But don`t hold that to me. I am setting up 2 house and 2 cranking batteries.

http://atkinsonelectronics.com/manuf...fs/MBCM-12.pdf

Tim

um, it looks like it pretty much does the same thing as the acr. but what about the 85amp max alt output?? I don't know what mine is but will it fry if its over that, maybe its 100-120 amp alt? Seems like the acr is much more simplier...as fas as wiring and hookup. acr is in and out plus a ground.

I'm with STV. 1st thing I'd do is replace your battery switch with a single Dual Circut PLus switch. That will work the same as 2 switches, but with less cables. Keep those motors isolated from each other. Been told EFI motors don't like to be combined, the ecms get some cross talk thru the common cables. Carbed motors no problem.
By adding that switch, and then the ACR between 1 of your start batteries (the one that powers your cabin lights) and the house battery, you'll never be dead in water. All 3 batteries will be isolated from each other when no charging source is operating. You can then hook all you want to that house battery and not worry about either of your start batteries getting ran down from it. For your house battery circut to be ABYC and CG compliant, those accessories need to go thru a battery switch, (On-Off) and then fused within 7" of the battery post.
Worst case sceneiro is you kill your house and the 1 start battery from running all your lights and stereo. No problem, just turn the dual circut switch to COMBINE, and now both motors will start from the always fully charged battery as it will never be connected to anything more than the 1 motor for starting. Providing you do away with the 1/2/All/Off switch.
I'm curious if your invertor parallels your house battery to your start battery? You know what brand/model it is?

This is the ACR going in my cruiser. It can handle 500A. It will also parallel the battery banks if I run 1 down, by a remote switch at the dash. No need to manually switch the battery switch itself. The ACR's so far in this discusion do not have the go-nads to act as a parallel switch for starting draw current, charging only.

My alternators are 65 amps. The configuration I`m doing is application 3.

us1, my engines are not efi, they are carbs. The battery switch shouldn't be a problem then...right. I don't really want to change that cause there are like 4 big cables that are routed very nicely to it. I will look tonight after work on the brand of converter/charger i have. All that was in the boat when i purchased it, that stuff is new to me cause this is the first twin engine boat i have owned. Thanks!

I think your best bet is going to be a battery isolator like they are talking about above. You can do a few other things to make it work like pulling a power wire from one side of your battery switch to the "house" battery. This works but you have to remember to turn your battery's to the off position when you overnight or are listening to the tunes. A battery isolator is your best bet in this situation. Also make sure your grounds are all tied together really well!

You wont change a thing by using the Dual Circuit switch. Your current switch has 3 studs on it, with both motors connected to 1 of them, and a battery to each of the remaining 2 studs.

The switch I'm suggesting has 4 studs, so you simply connect each motor to a stud of its own. The bolt pattern of this switch is the same as the Guest and Perkos, so even easierr. A simple 10 min swap and you will have a fool proof setup.

The Blue Seas 'Add a Battery' has both the ACR and battery switch for around $120.



Option 2, Easiest with only a new switch and battery required. For your application, this would be my recommendation. Simply and fool proof.

Replace 1 of your start batteries with another matching deep cycle battery.

1 motor to remaining start battery. (This motor/battery on it's own)

2nd motor to the 2 deep cycle batteries that are connected in parallel. You will do no harm using them to start your motor.

Use the Dual Circuit Plus switch to switch on/off both motors. Also requires no changing of wires as above, from what you have now. Just reconfiging them.

Use no ACR. Your inverter/charger is connected to your now house bank, giving you double the capacity for your house load, cabin lights and inverter power. When plugged into shorepower, the charger will charge your 2 house batteries, or all batteries if switch is in the COMBINE position.

If by chance you run the house bank down, simply turn the battery switch to COMBINE, and start your motors off the start battery.

ok, had some time to check out how everything is wired. The converter/charger is a Guess charge pro w/smart technology. My battery one is my left battery, my battery two is my right battery. Both engines will crank on bat 1 position, both engines will crank on bat 2 position and will crank in "all" position. ok...the house battery is currently charged only by the converter/charger, everything is grounded together, the hot from the house battery goes to a small fuse box, from there the amp is fused and a fused hot wire goes up to the small control panel in the cabin for all cabin lights, radio, and fresh water pump. So, looks like all overnight accessories are coming from only the house battery when main is turned off. if i disconnect the house battery, no accessories will work unless i turn on the main battery switch. This tells me that the other two "cranking" batteries are also tied into the accessories. So, when i am overnighting, i will turn my main battery switch to "off" and run only on house. My auto bildge pump works when main bat switch is turned off. This is probably wired into constant b+. I do want to get a acr so i can charge all batteries with the engines running. I will move the charge line from the converter/charger from the house to the other cranking battery, This way i can plug into shore power and have my two "cranking batteries" topped off. How does this sound?? I think it will work!!

Except the converter/charger will only charge the one battery it is connected to when plugged into shore power, unless you turn the main battery switch to ALL.

Question I have is you say the accessories work with the house batteries disconnected and the battery switch on either or both batteries? This indicates that the house and the switch are tied together somewhere.

the converter/charger will charge two batteries, i will have it so it will charge both of the cranking batteries when plugged in. Did i say that??? The cabin accessories will only work off the house battery....you are getting me confused...I'll try again tomorrow after work...pretty sure they wouldn't work if the house was disconnected. I will try again tomorrow and confirm. Thanks

Hard to follow when the house is powered in relation to the battery switch position, you counterdict yourself:

....."if i disconnect the house battery, no accessories will work unless i turn on the main battery switch. This tells me that the other two "cranking" batteries are also tied into the accessories. So, when i am overnighting, i will turn my main battery switch to "off" and run only on house."



Ok, you have a charger only. We are only dealing with 12vDC here. Makes it easier to discuss.

Is there a main cabin switch on the dash?

Sounds possible that the cabin is wired to the house battery only thru the fuse block, but that power lead goes thru a relay which is triggered off a factory ran 12vDC lead, thus the reason the battery switch has to be on for the cabin to power up.

I suggest to leave the charger connected to the house battery. That one will always have the largest draw down and should be your main focus. Being a 2 bank charger and wired as is, you are fine. Actually, I'd connect both output leads to the house battery only to double that charge, giving you longer battery life while plugged in at dock when the stereo and lights are on.


Your start batteries will always be charged just from the motors. Just starting the motors will draw down the batteries very little and will be replenished in several minutes of run time. The ACR will charge the house battery while the motors are running, and also charge the start batteries when plugged into shorepower if you run both charger leads to just the house battery. The good thing is, that change over can be done in 1 minute or less. So don't fret to much on that. ;)


Damn, didn't think this was going to be US1 Electrical. :)

I know...sorry guys, i will try it again tonight after work. I was wanting to move the charger off the house so it would charge from the motors because i never stay at the dock. We put the boat in and out and don't really want to have to plug it in everytime i bring the boat home to charge the house. When i plug the boat in the charger comes on and all the ac outlets in the cabin work, thats why i though it was a converter/charger, i also have microwave and frig in there. Thought about getting a dc/ac converter so i can run the frig away from shore power.. This will draw from house also probably.

Just plugging in the boats gives you your 120AC, which you see with the outlets. Gotta have 120 for the charger. If you have no AC while on the water, then you have no inverter. Standard shorepower features.

How the charger is hooked up make ZERO difference on how the batteries are charged while on the water, only while plugged in. Which is why I suggest leaving it on the house battery. Give it priority for charging.

CORRECTION: I have been in the boat playing around with fuses and switches. The house accessories are NOT tied into the other two cranking batteries. With the bat switch off and house battery on only, have all cabin lights and radio. Disconnect the house battery leads and turn on main battery switch to all and NONE of the cabin lights or radio work. So, i still feel like i need the acr to charge my house when im away from 120ac. If i don't do this and on the lake all weekend, i have no way to charge my house battery. us1, you are correct, its just a charger, followed the wires from the big rv plug, they split off and go to the charger and ac outlets, frig and microwave. Now, i may put a dc/ac converter on my house so i can run the frig out on the lake and even more reason to tap into alt for charging. Not really worried about the microwave though. I still think that the charger needs to go to the cranking batteries and charge the house by the motors when running via acr??? What do you think. Can you recommend a nice dc/ac converter that will run a frig, i need to look at the frig for the amp draw. Well, finially have this thing figured out. Ps...I may want to put a battery switch on my house bank just incase a cabin light gets left on while sittting in the driveway all week..huh??

Look at xantrex inverters (DC to AC converter). They make sizes from 1000w to 3000w in the Freedom line. That's what I was going to put in my Scarab to run the AC.

As I said before, I do recommend an ON-OFF switch on the house batteries. It's nice to be able to disconnect them to make sure there is no unintended battery draw.

yeah, i probably will. You had an ac unit in your scarab? Well, that would be nice for the kids to go down into the cabin and be able to watch tv and take a nap, while the wife and i....soak up the sun. do they make ac units for boats? how do they adapt on the cuddy??

Yes, you can install an AC for your boat. I put one in the Fountain. You'll need more battery power and a good sized inverter to run it though, same as with your micro. Is your fridge AC only? The one in my cruiser is DC, they also make some that are AC/DC. See what you have.
Your house battery will charge off your motors while running, going thru the ACR, so not sure why you feel the need to remove the charger off the house battery? Why you feel the need to put a charger on the 2 batteries that should be always fully charged from your motors is confusing to me. But I guess the ACR will charge the house secondary to your start batteries, so you'll still be ok. Just not the ideal setup. The charger and ACR are 2 completely separate systems. 1 has nothing tho do with the other. I've already beaten the horse on keeping the charger on the house. ;) But do put a ON/OFF switch on your house battery for emergency quick disconnect use.

us1, ok. Im not gonna take the charger out of the boat. I will leave it hooked up to one crank and the house battery. I have looked at the back of the frig and i only see a power cord. The ac setup looks great, looks very involved though. I do want to get a switch on the house, i guess i'll get one of the orange ones like i have so they will match, don't know the brand. Do you have to worry about your house going dead while running the ac unit? how long will it run? I do like the idea of having one for the kids though. Its a new boat for us, want to enjoy it first, have already spend $2500 in new gimbal rings, bearings, boots, cables, trim switches and senders.....you know the deal. Got the reworked rings and stuff from jr marine...great guys and products too! I still have to put the transom plugs in the holes before putting it in the water. Hey, i really appriciate all the helpful info, im not new to boating just to the twin engine setup. like i said, i had a 24' baja and always wanted to step up to twins. Got this boat for a really good price. I will probably put heat in it before the ac, that way we can go for a boat ride early or late in the season, plus, my old man dont like that damn cold anymore..

us1, I see you are in lafayette, where do you boat up there? we go to the ohio usually but want to hit up some lakes this summer, maybe cumberland or dale hollow. Have you ever been to thunder of louisville, we are planning on going next month, hopefully the river won't be completely trashed...but it usually is this time a year.

We have a slip in Bloomington (IU country) on Lake Monroe. Are there every weekend starting as soon as temps allow, usually early May and go till Nov 1st. Haul your boat up here this summer. We try to hit Cumberland at least once a yr now for the poker run, just gotten too comfortable with the convience of hopping in the econo car and driving to the lake were the boat is sitting there waiting for us. I do have a cabin reserved for this yrs PR, so will be there for sure. Missed last yrs do to no accomodations and last minute planning. Been to the Thunder a couple of times several yrs ago. Loved it! Fireworks that shake the ground setting off car alarms. :D

Look at the spec plate on your fridge, it should state AC or AC/DC use. Probably just AC though, otherwise I'd think it'd be wired D/C too.
Both my boats A/C units are R/C, so they cool and also heat. These are an all in one unit.

I can't run the A/C in either the Fountain or Baja, unless plugged into Shorepower or running a generator. A Honda 2000 is perfect here.
No invertor on the Fountain, and the one I put in the Baja is only 800W to run the blenders for the girls Margarittas drinks and what knots. I didn't see the need to install a larger one for A/C use since that would have been more costly and required a large battery bank, plus we just don't use A/C while out floating. That's what floaties are for. :)

Well, I BOUGHT the A/C for the Scarab...it's been in my garage for 3 years. LOL I have the Mermaid Air 6500BTU setup. It's one of the lowest draw units on the market. They claim it can be run off a single Honda EU1000i generator (it's AC power). Here's the specs: http://www.mmair.com/marine_division...500_btu_system It's supposed to draw 6.4amps to run it, plus the water pump draw, so not that bad. However, it pulls almost 12amps at startup.

Anyway, it needs AC power and you have to run a water pump to send water to it for the heat exchanger. It takes water in from the outside, runs it through the heat exchanger and then dumps it back overboard. The unit is pretty compact. I have a perfect place to put it in my boat, just behind the cabin bulkhead, but just haven't got that far.

Check out the ON-OFF Blue Sea units. 600amp rating. That's what I have on my house battery.

http://bluesea.com/category/1/productline/4

Nice switch, but way overkill. You'd have to have at min. 2- 2/0 (huge) wires on each stud, both in and out, to require a switch of that rating.

They are 1/2" studs, but I ran 4ga wire from my two house batts, to the switch, then to the helm for the stereo and VHF. Don't need the rating really, for what I am using it for, but it's a nice, clean looking switch that does the job and matches form factor with my engine battery switches.

Cranking Rating: 10 sec. 2,750 Amps
Cranking Rating: 1 min. 1,325 Amps
Intermittent Rating: 5 min. 900 Amps
Continuous Rating 600 Amps