Battery Seperator Switch

[StreamingAI]

2017 Interstate Grand Tour
Does anyone know the manufacture and model number of the battery separator switch? ST-! on the 12 volt schematic

[Boxster1971]

Originally Posted by StreamingAI

2017 Interstate Grand Tour
Does anyone know the manufacture and model number of the battery separator switch? ST-! on the 12 volt schematic

WELCOME to AirForums!!

You might get more responses if you post in the "Sprinter and B-van Forum" subforum.

My 2013 Interstate has a battery separator made by Precision Circuits Inc. (PCI).
https://precisioncircuitsinc.com/cat...ery-isolation/

I think they still use a separator from PCI, but might be a newer model on your 2017 coach.

Hope this helps,

[wachuko]

This was on my 2018 Airstream Interstate...

Boxster1971 gave you the specifics on the company.

And do yourself a favor and remove it and replace it for a Blue Sea ML-ACR 7622... one less headache...

https://www.youtube.com/watch?v=s_oKQ_N8_EY

Or I can send you mine if you want to stick with this unit. I removed it the first week I got my new AI...

Here is a recent thread of someone that replaced theirs for the Blue Sea ACR

http://www.airforums.com/forums/f240...lp-199867.html

[uncle_bob]

Hi

You can save a little money by going with the 7620 over the 7622. The gotcha is that you then loose the neat yellow switch rotary lockout on the unit. I do indeed like that lockout and have it on the units I bought. Functionally that's the only difference and there is a cost savings involved.

Bob

[wachuko]

Originally Posted by uncle_bob

Hi

You can save a little money by going with the 7620 over the 7622. The gotcha is that you then loose the neat yellow switch rotary lockout on the unit. I do indeed like that lockout and have it on the units I bought. Functionally that's the only difference and there is a cost savings involved.

Bob

Bob,

Spot on. Good savings there if you have no need for that extra switch. I did not...bought the 7622 without knowing of the 7620. And since my install is under the seat, more reason not to spend the extra $$ on that model.

Thank you for calling that out

[StreamingAI]

Thanks everybody for the quick response.
I'm knew at this and will get in the correct forum next time.

[Boxster1971]

Originally Posted by uncle_bob

Hi

You can save a little money by going with the 7620 over the 7622. The gotcha is that you then loose the neat yellow switch rotary lockout on the unit. I do indeed like that lockout and have it on the units I bought. Functionally that's the only difference and there is a cost savings involved.

Bob

Good idea Bob. But I also like ability to lock out the battery isolator function when performing electrical maintenance. When I rewired my stock BIM I added several features. The attached drawing shows the changes I made to provide remote indications of battery combinations, battery charging meter on driver dash, ability to force a connection (boost) and ability to disable the BIM function.

Some might find this helpful.

[wachuko]

Originally Posted by StreamingAI

Thanks everybody for the quick response.
I'm knew at this and will get in the correct forum next time.

And the reason for changing it is because the stock unit would allow the batteries to drain more than it is safe before isolating... that is the short explanation version...

More details here:

http://www.airforums.com/forums/f240...ml#post2017417

And there is one more thread...let me see if I can find it.

Here you go...more detailed explanation

http://www.airforums.com/forums/f240...ml#post1991001

[1919]

I am with Wachuko. My Interstate 19 had the house and chassis battery connected at random. Also. Not charging fully when driving. Replaced with Blue Sea. Problem solved. I had gone to the dealer twice to rectify the issue. So I solved it myself.

[ONDaroad]

Maybe someone can comment on the below issue I've uncovered.
Love to hear what you have to say, thanks!

There are may threads about replacing the stock Precision circuits battery isolator/combiner with the Blue sea ML-ACR unit. After reading these threads I went ahead and took out my Precision Circuits for all the benefits they said such as better switching voltages and minimal parasitic draw and replaced it with the Blue Sea ML-ACR. Then, while reviewing the documentation on the Precision circuits 00-10021-000 I found a functionality which the blue sea does not appear the have.

The Precision circuits unit has a feature which disconnects the engine from the coach batteries after one hour of driving time, then looks at the coach battery voltage and waits until they discharge to 80% before reconnecting the engine battery/charging circuits again. This on/off feature is designed to protect the coach batteries from being overcharged by the alternator when you were on the road for many hours.

The scenario would be the first hour of driving the car alternator is charging the batteries at Absorb voltages (14.1-14.2), then after an hour the switch opens, charging to the coach batteries stops and doesn't resume until the coach batteries drop to 80%. Im, not sure exactly what voltage they used for 80% , but its not a fully charged battery and I think that is the point, to wait until they drain down before applying more charge to the battery from the engine.

I believe there is a problem using the ML-ACR in this application because that unit will keep the switch closed as long as one side of the switch is at 13V or higher , thereby keeping coach batteries hooked up to the engine charging circuits as long as the engine is running, whether they need to be charged or not. Also, the 2013 Interstate is set up for a wet cell engine battery and the alternator puts out a voltage of 14.1-14.2 sometimes higher while driving which would keep the coach batteries in a constant state of charge at "Absorb" voltage levels for as long as you are driving, never reducing to the AGM float level of 13.3V therefore constantly overcharging the batteries reducing their life every time I go on a road trip.

Does this make sense to anyone?

I'd appreciate and insight you may have.