What is this switch for?

[BroncoHauler]

Originally Posted by scatter

This is the way my '07 works John, but the problem is (with the diesel) that when you turn the key to on to heat the glow pins, the house batteries are not helping the starting batteries and the glow pins do not heat up. When I turn to crank, the house ones kick in and the engine cranks fine, but takes a long time to start (especially when it's cold outside) without glow pin heat. I'd like to rewire it so the house batteries kick in when the key is in the on position. Any thots???

"Glow pins? We don't need no stinkin' glow pins!"

You're in Baja most of the year. Are you a reverse snowbird, and spend the Winter in the cold parts of the US?


Herb

[bgoetting]

Turns out that my SMB has a battery separator that should kick in and start my engine automatically if my starter batteries are low. It obviously didn't work last Sunday. I repeated the situation today by leaving on my lights until the batteries were almost dead. Still didn't kick in. I spoke with Peter at SMB and he didn't know what was wrong but said that I could jump it manually by connecting the two big red terminals on the separator (which is under the sofa on my 50). He also said that there needs to be a minimal voltage in my starter batteries in order for the separator to do it's job. There was enough to make my alarm go nuts but still no engine start. I shorted the two terminals on the separator and it instantly came to life, providing battery power to start the engine without having to continue shorting the terminals. Now I at least know what to do. The manual doesn't even mention "battery separator". Anyone have a guess why it didn't work?

[Scalf77]

Here is the documentation from Surepower. You need to check if aux start wire is hooked up OK


Greg

[John Kalmbach]

Scatter, I suppose you could wire in a relay that would allow the Battery Separator to connect the batteries from an independent switch, while also retaining it's automatic function. The nice thing about the automatic mode is that you don't have to worry about forgetting to turn a switch off and thereby discharging all the batteries.

Bgoetting, I'm glad Peter mentioned connecting the two large terminals. With heavy-duty jumper cables you could do this and completely bypass the Battery Separator. I seem to remember that the Battery Separator will stay in an "open" mode if the voltage on one of the battery bank's ever gets really low, by performing a quick jump across the two large terminals, you've "reset" the Battery Separator so that it is operating properly now. This was a common problem in '04 and '05, I forgot to mention it earlier. I don't recall this being too much of an issue in later models. Quite frankly, I'm not sure why the later models didn't have as many issues. Perhaps having the Battery Separator wired to the "start" circuit rather than the "on" circuit has something to do with it. Also, more people started installing solar panels in the later year models which cut down significantly on battery issues.

Also, I think that your Battery Separator is connected to the "start" circuit because of how you described leaving your ignition "on" and the house battery not getting discharged. Leaving the circulating fan "on" may have been what put the Battery Separator into it's "open" mode.

The Battery Separator connects the battery bank's when one, or both, battery bank's reach about 13.2VDC, and separates them at about 12.8VDC.

I hope this helps!

John K.

[scatter]

Originally Posted by Bronco_hauler

You're in Baja most of the year. Are you a reverse snowbird, and spend the Winter in the cold parts of the US?

Yeah, seems like I can't get anything right. But then again, one can only stand so much eighty degree weather, great fishing, cold cerveza, water skiing, quad and bike riding, cold cerveza, great camping, exploring, cold cerveza, etc, etc, etc. Gotta come back to reality once in a while. Wait a minute, all that is reality.
If all goes well next week, I'm otta here for the beaches for one last run before the summer heat kicks in.

Originally Posted by John Kalmbach

Scatter, I suppose you could wire in a relay that would allow the Battery Separator to connect the batteries from an independent switch, while also retaining it's automatic function. The nice thing about the automatic mode is that you don't have to worry about forgetting to turn a switch off and thereby discharging all the batteries.

I thot of that John, but the problem occurs so seldomly that what I found works best for me is to unplug the lower green wire off the seperator and use a small jumper from the green wire terminal to the large starter battery terminal on the seperator. This kicks in the seperator, connects the house battery in and gives me the juice to heat the pins. With the seat up in the air (RB50) I don't forget to remove the jumper and connect the green wire. Whatever, works for me.

[bgoetting]

Given that this separator often fails, and even when working requires a minimal voltage to engage, I think the old system with the steel switch pictured at the top of this thread is better. Simpler is often better.

[Scalf77]

Has anybody tried wiring the lamp as shown in the surepower data, it would be interesting to see if it worked correctly. My van was a early adopter of the surepower separator (May 04) , I have not had any problems with, but I have never had to rely on using it to jump the start battery either. I would tend to agree the manual switch would appear to be the best solution. It seems that I have heard of enough people having issues with starting batteries going bad, but the automatic power boost was masking the issue.

Greg

[bgoetting]

Thanks Greg for providing the PDF on the separator. The wiring diagram shows that you can wire it for automatic or manual operation. Since it requires 3V minimum to operate automatically, I can't imaging why SMB wouldn't just install a manual switch, like they did in earlier years. If someone leaves a light or fan on, like I did, you may very well find your starter batteries completely dead. With the automatic configuration, you're screwed (unless you happen to know the function of the separator well enough to "jump it", like I do now). Alas, my SMB manual didn't even have the separator info so I couldn't figure out how to rescue myself even by pulling out the manual. I'm kind of mad when someone "improves" a design this way without thinking it thru.

[daveb]

Maybe I'm drinkin too much...Why can't you use a momentary switch? I mean even if it just activates a relay???

[John Kalmbach]

The photo at the beginning of this thread showing the silver momentary switch was typically used for Pre-Battery Separator SMB's that used the older style Battery Isolator. This switch energized a conventional battery solenoid switch which would join the battery banks together to help "jump start" the engine.

As Dave has mentioned, you could install a similar momentary switch to manually operate the Battery Separator. You might need to hold it down for a little while if you need the glowplugs to assist in starting as Scatter has commented on. I think that if you want to retain the automatic operation too, you would want to use a relay to prevent any cross-over voltage into the starting circuit.

While I like the idea of adding the momentary switch, I'm not entirely sure the momentary switch would have helped in bgoetting's scenario. Since the Battery Separator was in an "open" mode, it had to be "reset" by jumping the terminals. I remember seeing Battery Separators stay in an "open" mode, even after the engine was started using an independent battery boost. This was evident because the voltage of the starting battery was over 14VDC when the engine was running, while the house battery was below 12.8VDC until the Battery Separator was "reset".

It's possible the Auxiliary Start Activation feature of the Battery Separator would "bypass" the "open" mode function, but I don't think it would. It only takes 3VDC to activate the Auxiliary Start feature, almost any starting battery would self-charge itself above 3VDC once the load discharging it was removed.

I hope this helps!

John K.