Electrically challenged....Help me design a house battery system

[gtbensley]

Yes its a type II, has a basic on off switch right on the seat and two starting batteries wired in parallel.

That is something I was working on mulling over, a deep cycle and a starting battery would work, until the time comes to charge. How would a ACR have an affect on that though? It is tying the two banks together to charge, just like a manual switch to the both location will.

Wouldn't the ACR also kill my power from the "house" battery once the voltage has dropped in that battery?

I already kill the power switch whenever I leave the vehicle for the most part, so already in the habit.

 

[patoz]

That is something I was working on mulling over, a deep cycle and a starting battery would work, until the time comes to charge. How would a ACR have an affect on that though? It is tying the two banks together to charge, just like a manual switch to the both location will.

You got me thinking about that, so I called Blue Sea Tech Support to get the straight dope. From reading the info on their website, I was under the impression the ACR could route charging current to the individual battery(s) as determined by it's sensing feature, but as you said it's a simple switch so that can't happen. In reality what happens is, the sensing feature measures both batteries simultaneously (this is what was confusing) and based on it's findings decides when to close the contacts and when to open them. If one battery is below the acceptable threshold, the contacts close and both batteries receive charging current. Then both batteries tend to equalize and come up equally or close to it. Once full charge is reached, the contacts open again.

The model I'm referencing is the ML-ACR 7622, which comes with the remote control switch. This switch will allow several other functions also, such as locking the batteries together to jump start the vehicle.

Wouldn't the ACR also kill my power from the "house" battery once the voltage has dropped in that battery?

Yes, unless you identify your 'camping' loads and move them to the House battery. See this wiring diagram Here.

I would suggest performing a series of test to find out what will work with that battery switch under the seat 'ON' and then 'OFF'. If your vehicle will start with the switch OFF, it's possible it only controls the rear and emergency lights, but not necessarily. Testing is the only way to find out for sure.


Also, I have edited my OP to reflect what I found out from Blue Sea Tech Support.

 

[gtbensley]

You are a wealth of information, and for that I thank you.

That switch seems to shut off 99% of my vehicle. The radio, ignition, everything except when I open a rear door my interior lights will come on for 2 minutes and then shut off but thats all I have being powered. The thought with that switch is it must power most of the vehicle through it. So installing a house battery to that and powering through it will basically give me two identical system. One used to start and one used as a house.

 

[luthj]

The ACR is also called a voltage sensing relay. It is simply a switch with a logic circuit that measures voltage to determine whether it should be opened or closed.

Starting with the batteries separate, the ACR watches the voltage of both batteries. When either battery rises above a certain threshold (usually around 13v) the ACR will close connecting both batteries. At this point both batteries will be at the same voltage. The ACR will continue to monitor this voltage. When the voltage drops below a certain threshold (usually around 12.8v) the ACR will open separating the two batteries. This means that whenever either battery is receiving a charge the ACR will close charging both batteries. When the batteries are being discharged the ACR will open preventing the starting battery from being drawn down.

 

[gtbensley]

Think I will stick with a manual switch, it will have the same impact but gives me more control.

Think the current switch and wiring can handle the type of current? I know, I should just pull it apart and check.

 

[gtbensley]

This is under the seat, the labels are my best conclusion of what's what. Basically just going to add in a three way switch for a house battery. SHOULD feed the vehicle exactly the same as it is currently I believe. Only difference is it will only be charged when selecting both on the switch.

Seem right?

 

[patoz]

The manual system you are wanting to install will work, and is the same as what we used back in the '70s on our 4WD vehicles to help with then winching. With this type of system you only have Battery 1 and Battery 2, and not Start Battery and House Battery, simply because your House loads are not separated from the vehicle loads.

Everything will be switched and monitored manually, and as long as you NEVER place the battery switch in the OFF position while the engine is running, you will be OK. If you do hit the OFF position, even accidentally, while the engine is running, you may possibly blow the diodes in the alternator.

Blue Sea does make switches that have an Alternator Field Disconnect (AFC) option, which I would recommend, that will protect your alternator if OFF is accidently selected with the engine running.

You will need one of these 4 switches depending on your amp load. When in doubt go big.

HD-Series Heavy Duty Selector Battery Switch 3002 – 500A with no AFC
HD-Series Heavy Duty Selector Battery Switch 3003 – 500A with AFC
e-Series Selector Battery Switch with AFD 9001e – 350A with no AFC
e-Series Selector Battery Switch with AFD 9002e – 350A with AFC


Switch positions:

Switch set to 1

Switch set to 2

Switch set to 1 + 2

I would also recommend you install a Volt meter(s) on the dash or console, so you can monitor the status of each battery. You can do this two ways.

1. Install a meter for each battery.
2. Install one meter and use a SPDT switch to select between each battery to monitor.

You will only be able to get an accurate reading of the battery status when it is disconnected from the alternator (not charging), otherwise the meter will read the charging voltage from the alternator. Try to keep the battery voltages as close to each other as possible, under normal circumstances. This will help with battery life when charging both at the same time.

 

[gtbensley]

Exactly, while it wont be a true house system it will allow me to use a bank as a house and a different bank for starting. I believe my current switch will also botch the alternator if I switch to off while running. I think to use the AFC feature the alternator must have an external regulator input correct? Mine is all internal so I am not sure that feature would work correctly.

Going to order a switch and some cable to attache the new battery with to the switch. Thank you for all the input and helping to clarify a couple things.

 

[patoz]

Good morning,

Amazon is about the best bet for price that I've found so far. Personally, I would go with the 500A version, and that way you are pretty much covered for anything you may want to add, especially a winch. However, a winch is usually wired directly to a battery.

350A Model - https://www.amazon.com/Blue-Sea-Sys...Series+Selector+Battery+Switch+with+AFD+9002e

500A Model - https://www.amazon.com/Blue-Sea-Sys...eries+Heavy+Duty+Selector+Battery+Switch+3003

...the alternator must have an external regulator input correct?

Yes, they do.

This is from the instruction sheet, which really doesn't explain much, but maybe there is more info included in the actual product. If not, you can call customer service Monday through Friday, 8am to 5pm Pacific Time. at 800.222.7617 and get very good help.

When I called, I was halfway expecting the runaround like you get from most large companies, but not so. Dialed the 800 number, pressed 2 for Tech support, and a young man answered on about the 4th ring who was a technician. No transferring around or anything. He was very polite, very professional, and he knew exactly what he was talking about. He was not in any hurry to get off the phone, and waited until I was completely satisfied before ending the conversation. Great experience!

 

[gtbensley]

Good Morning, did you call on my behalf? You really are going above and beyond with the help you have given me. Going to run a 500 amp switch and 2 gauge wire so it should be good to go and able to handle loads. At most, it might be supplementing my starting batteries if they get tired in the cold, although the point of the house battery is to keep them in tip top shape.

Hopefully getting some interior trim pulled off tonight so I can figure out how to route the battery (might due dual 6v batteries actually)

 

[patoz]

I called about three days ago, when we were discussing how an ACR actually works. It was no problem because I needed to know myself, and had been wanting to call them anyway just to check out their Customer Support department.

 

[gtbensley]

Digging in the shop I just found a three way switch for constant 210 Amp with intermittent 350 Amp. Think thats going to be too small?

 

[patoz]

Digging in the shop I just found a three way switch for constant 210 Amp with intermittent 350 Amp. Think thats going to be too small?

That's pretty small but you could try it. I would probably leave it unmounted for awhile so you can monitor the temperature of it. If it starts getting pretty warm or hot, then it's definitely too small. It all going to depend on what your loads are which will vary, so you'll need to monitor it quite often.

What brand/quality switch is it, because that can make a big difference also. And since you didn't mention it, I'm guessing it doesn't have the Alternator Disconnect feather either.

 

[gtbensley]

I am not sure on the brand, will need to go look at it again. Nope no disconnect for the alternator, while nice, I am already in the habit of being careful with the current switch so I am not too worried about that. Maybe I will just put it in and see how it works while I wait for a better one to come.

 

[patoz]

Well good luck, just don't let the smoke out of anything!