Charge chassis battery from shore power? (w/ battery separator)

[unreng]

George.
Is it possible to take some photo's of the ACR + wiring?
Please reference this troubleshooting guide...it helps for manual AND auto switching - http://assets.bluesea.com/files/reso...FAQ_Matrix.pdf
Page 2 of the wiring manual shows how to operate the yellow switch - http://assets.bluesea.com/files/reso.../990180180.pdf
Does your vehicle have this switch?



To add the Scalf's (greg's) diagram above, here's BlueSea's wiring diagram:
Emphatically support Scalf's statement to centralize electrical grounds...it makes electrical troubleshooting soooooo much easier.
If you have the capability, would recommend changing the ACR ground wire from the van sheet metal to a common ground. According to other websites reporting 7622 issues, this was a main cause of 7622 malfunctioning.
Regards.
Chris

[geo2015]

Thanks Greg and Chris,

So I just went and bought a basic multimeter. A reading across the chassis battery read 12.46 volts. This is with the van plugged into shore power. So then I just cut the red wire and within a few seconds I heard a loud click from the ACR and the voltage jumped up to 13.1 volts.

It seems to me that this solved the problem. Am I wrong?

Thanks again.

George

[Scalf77]

George,
It does sound like that "fixed" your problem. You need to make sure that wire is taped off properly. It would be good to know if that wire is "hot" has 12 volts when the van is running.

This would confirm that they are wiring the ACR wrong. As I said and you can see in the Blue Sea Documentation the red control is only needed if wired into their switch or similar type switch.

It should also be noted that when the van is running while you are connected, the ACR is connected but the voltage monitoring is not in working since you are overriding that feature while holding the control line hot.

To be honest if I was any of you guys that has this wired wrong, I would report this to Sportsmobile, I do not believe this is the intention, but instead a misconception of how it should work.

-greg

[Scalf77]

To follow up, I did just try to reach out to Sportsmobile on this, I will try to make a post if I make any progress with this. Also, I did make a video on the operation of the 7620-22, I don't think it was ever made a Sticky like some of the others so it harder to find.
http://www.sportsmobileforum.com/for...2-a-16340.html

It's been a while since I did it or viewed it, but I believe I did a pretty good job of covering how it works.

-greg

[Orv]

Originally Posted by AndrewInSeattle

I haven't needed to try this yet, but the owner's manual that Sportsmobile West provided for our 2017 build said somewhere that you can jump-start the chassis battery from the house battery by holding the key in the ignition position for 10 seconds.

That's how mine works. My van just has a heavy-duty relay (looks a lot like a Ford starter contactor) that's wired to the ignition circuit. When the key is in the ON (not ACC) position, the two batteries are paralleled, the rest of the time they're separate. With this scheme the chassis battery will *not* charge off shore power, but both batteries will charge off the alternator. It sounds like the OP's setup is a lot more sophisticated.

[Scalf77]

The real problem is that they are trying to mesh old with new. I agree a simple solenoid connected with the van is running works great alternator charges both systems when it is running, separates when not.

The idea of the "smart isolators" like the Blue Sea ACR is that they monitor the voltage of both batteries, and if either one is above a certain voltage they will connect and charge the other battery. When the alternator is charging the starter the voltage goes up and the two system connect. Stop the engine the batteries fall below 12.8 and they disconnect. If you have shore power or solar charging your house battery the same thing happens, making it a bidirectional unit. The other nice thing about the BLue Sea ACR (7620-22) is that they are a magnetic latch relay, meaning there is no power used to keep the latch relay open or closed.

Sportsmobile seams to be trying to add the start assist feature of the Surepower 1315-200 , the first "smart isolator" they used starting in 2004. The problem is that by hooking the control wire to the "run circuit" they turn the "smart isolator" into the simple design. So it charges the house while the van is running, but doesn't have any of the smart voltage monitoring features, and is no longer bidirectional. When the van is running the control wire is at 12 volts, forcing the ACR to connect. When the van is off the control wire is now low or grounded and this forces the ACR to disconnect. The control wire overrides the voltage monitoring function of the ACR. So in the end the only advantage you get with their installation is magnetic latch relay versus on continuous power relay(solenoid).

If you instead install the SPDT ON-OFF-ON switch, left in the normal off position the ACR will monitor the voltage and connect and disconnect accordingly. The other two positions of the switch are wired to ground or 12 volts will disconnect or connect the ACR accordingly. In their defense they are probably worried that a owner will leave the switch in the wrong position accidentally.

-greg

[geo2015]

Greg,

Your video on the ACR 76220/22 is terrific ! Very informative.

I will tape off the cut ends of the red control wire as you suggest.

So I took some additional voltage readings just out of curiosity.

With the engine off (no key in ignition) but with shore power still plugged in, the current reading across the chassis battery is 13.17 volts. The red wire coming from the ACR is 4.23 volts. The cut end of the red wire that disappears behind the upper dashboard is 1.44 volts.

With the key in the ON (or accessory?) position (with the engine off): The chassis battery dropped slightly to 13.08 volts. The red wire coming from the ACR is unchanged at 4.23 volts. The cut end of the red wire that disappears behind the upper dashboard increased to 13.06 volts.

With the engine started: The chassis battery increased to 14.45 volts. The red wire coming from the ACR is unchanged at 4.23 volts. The cut end of the red wire that disappears behind the upper dashboard increased to 14.45 volts.

Any thoughts?

Here’s another thing I’m confused about: Remember when I said (before I cut the red control wire) that when I depressed the yellow button on top of the ML-ACR (with the switch in the left-hand position), the button would just snap back up and not lock in the depressed position. When I just checked it again now, without even touching the button, I found that it is now in the depressed position. Does it do this automatically whenever it automatically closes the circuit?

BTW, you mentioned reaching out to SMB on this. Please note that my installation was done at the Austin location

Thanks again.

George

[Scalf77]

George,
Your voltage readings sound OK, it looks like the read wire goes up to the key switch or circuit that is controlled by the key switch. A circuit that has power on it when van key is run or accessory. Once you have cut the wire to the ACR, the ACR side is floating, it is a input and does not put out a voltage so read about 4.23 volts. Notice also while the van is off , the red wire from the dash is reading 1.44 volts, while not ground it loaded down enough for ACR to see that as an off condition. If you were to hook the two red wires together, the ACR would see the 1.44 volts and disconnect.

Yes, if the ACR is connected you would see the internal knob button depressed.

So this change will make your ACR work as expected. I would certainly look at getting the switch installed, just for the extra functions, indicators, and diagnostic functions it provides.

-greg

[geo2015]

Terrific. Thanks so much for all your help in working this out. I will order the 2146 switch and get it installed.

George