Battery separator under hood cycling

[Roly]

I bet Mr. Blue knows the answer to my question, maybe has addressed it in here somewhere:
My 1998 Premier still has the LVD and combiner it came with, but with a Progressive Dynamics charger / distribution panel, and an incomplete solar installation not yet hooked up.
With shore power plugged in I hear the relay under the hood cycling every 7 -12 seconds. I believe that the LVD is wired correctly, though I have been messing around in that ares adding the solar controller and cabling. What might cause this?

Thanks in advance, Roly

[Blue~Go]

So basically, the SurePower 1315 (or the Blue Sea 7622) is a bi-directional relay. It allows to banks to share charging sources when times are fat, and then protects the "other" bank when one is experiencing lean times.

When one of the banks (house or start) discharges to a certain point (let's say 12.5 volts just for example), the relay will open, separating the banks, and thus "saving" the other bank from also discharging). On the other hand, when a certain voltage is detected (usually something like 13.5, i.e. charging), the relay says "Oh, it's okay to close again and share the wealth." So it closes and connects the banks. Then if the voltage goes low again, it opens. Etc. Etc. Normally these two things are separated by a period of time; but if something's not quite right it can get in an endless cycle of open/closed/open/closed (click, click, click).

So if you have something that's making a big draw (discharged start battery, for example) then you might get an endless cycle of "13.5 volts, oh goodie, I can combine!" then "Oh dear, low voltage, I'd better open to save the other bank." then "Oh good, I can combine!" ad nauseum (clickety, click click). Or maybe a large/discharged house bank.

Does anything here ring a bell with what you've got going on? Or anything else you can say about what might be charged/discharged/drawing and when the clicking does or does not happen?

Here's a link to a Blue Sea article on why combiners can cycle. They explain things really well. There are some differences in how the Sure Power and the Blue Sea ACR function, but the principles are the same. One additional factor, if I remember correctly, is that the Sure Power draws something close to 1 amp when closed (The Blue Sea uses a magnetic latch so has no draw), so that may factor in if things are tight, charging wise.

https://www.bluesea.com/resources/527

Not to "drop" you or your question - do come back!

BG

[Manitou]

Wasn't the default one only unidirectional? I replaced with a bidirectional and it burned out in a year. I went back to the unidirectional one now.

[Blue~Go]

Wasn't the default one only unidirectional? I replaced with a bidirectional and it burned out in a year. I went back to the unidirectional one now.

My Concourse came stock with a Surepower 1315. Unless Surepower has changed their offerings, the 1315 is bi-directional. There is also a Surepower 1314, which is uni-directional. I don't know if/when in the various Chinook production years after mine the stock model was changed to another one from the 1315 (or an individual one could have been replaced over the years), but I wouldn't be surprised if it were.

Since Roly has a 1998 Premier, and I have an early '99 Concourse, I wouldn't be surprised if Roly's rig had a 1315 (but if that's not the case, let us know).

I didn't really want a bi-directional effect - after living with the rig for a year or so to get used to how it functioned - because my start battery doesn't deplete over a period of months (in other words I don't have any parasitic loads to speak of on the start battery). I also don't really want "stupid" alternator charging getting to my precious house bank very often (if ever). And that's fine because I only very rarely need it. Those two qualifications led to me putting in a manual switch. I operate it only once in a blue moon. Either to self-jump start (not needed yet), or to put some bulk charge into the house bank (used two or three times only). In the future I will set it to combine when running my "inverter as minimal use generator" scheme.

If I had put in an ACR I would have wanted the Blue Sea 7622, but then I would have added additional wiring to make it uni-directional (it's bi-directional).

[A Rooney]

Rooney with 2001 Premier,with bi directional battery separator,my understanding was bi was the chinook standard stock oem,separator....I recall a thread on this on the other forum,also "I believe" the cutoff voltages on the surepower are lower for the charge and higher for the cutoff,then blue mentions,I do think it could be possible,(tentative) that the surepower may not be as 'smart' as it is touted to be.I forget who took over manufacturing of the surepower,(again search other forum) but I called them at one time to discuss their function and design,with a customer service/engineer rep.It was a good conversation but I was not convinced my unit was functioning exactly as the rep explained.I understand the logic of going uni directional,but as you might imagine if I did go unidirectional I might go in the opposite direction as Blue.I understand the logic of the alternator being a dumb charger,And using sterling b2b or unidirectional separator as blue described,but so far I have seen no evidence with my monitors of overcharging house batteries by alternator driving long distances in a day.Granted I am only going into my 3rd year with the batteries,and obviously I have only limited personal ability to ascertain battery damage.Sorry 3 yrs isn't enough to know for me,I hope to get at least 6 years of service so all my comments about no sign of battery damage with a bi directional separator should be taken in abeyance to a post 3 years from now. I am not afraid of acknowledging the disasterous courses of my life,so of course should I detect battery damage or deminished serviceability I will not hesitate to report that.for the record and knowledge base.......

[Blue~Go]

Rooney,

My guess is that you would have no concern with over-charging of your batteries from the alternator. I run a Scangauge on my dash, and it shows the alternator voltage. Of course it fluctuates, but at least on my '99, it's typically between 13.6 and 14 volts.

Next, the Surepower has a bit of voltage drop (.5 -.75 amps comes to mind, but don't quote me on it). Then, presuming the stock 4AWG combiner wire at around 16', there's an additional 3% or so (at 40 amps). In addition, if your house bank is below 77ºF at the time of charging, its desired voltages go up a bit for each degree (i.e. they want higher voltages when colder; lower when warmer).

And then too, most people don't just drive for days on end (like say you might plug in a shore charger and leave it for a week or tw0, solidly on all the time- now if that is charging at too high a rate it could be a problem).

Given all these factors, I would think the bigger danger would be undercharging. Especially if only using alternator charging.

That said, since I don't need additional charging 99% of the time, I'd just as soon cut the dumbest of my chargers out, and that's the alternator. So I do, because why not. But that doesn't mean that if you do use yours it's going to overcharge the batteries.

****

On the cut in and cut out voltages, I was just throwing out example numbers to show the concept of how they work. I don't remember (or maybe never knew) the numbers for the Surepower 1315. I'm more familiar with the Blue Sea ACR. I don't have one in my Chinook, but do on another system (not the 7622, but the 7610 as it's a smaller system). If I recall correctly, it opens at 12.75 volts and closes at 13.6 volts (when these are sustained for at least 30 seconds).

[Roly]

I lifted the ground connection on the 1315 to make the clacking stop. Normally open, I think. If I want to get ""both", I'll reconnect the ground wire and push the connect switch in the cab roof. Then when time permits I'll go with the Blue upgrade. You discarded the LVD, too, didn't you, Mr. Blue?

Thanks, Roly

[Blue~Go]

Hi Roly,

Always enjoy "follow up" reports.

Yes, I re-did what I'll call the core electrical distribution system. So the LVD was not needed, and, in fact, it's function wouldn't really do what it was intended to do (because the voltage level that it disconnects at is low enough to be damaging). To me it was a bit like having a fuel gauge that shows you nothing until it shuts the vehicle down just before you run out of gas.

I have things set up so that I have enough power to meet my needs (so the batteries don't get that low), but I also have meters to keep an eye on things. That's not to say I can just go wild running appliances without a care, but since that's not one of my desires it's more than I didn't design in that capability. But, as with things like water supply and holding tanks, one is somewhat always running one's own "private utility," and as such you have to keep track on some level.

Anyway, so I redid the main system, eliminated the LVD, and purchased a Blue Sea 7622. For various reasons (which I could elaborate on, but since you may not care, I'll spare you for now ), I decided to go with just a switch-plus-indicator light. I've been completely happy with my system for two years now, primarily boondocking. The one thing I have yet to add, which will be welcome, is a couple of solar panels on the roof. I'll keep my 200 watts of ground panels, because I like to park in the shade, plus I like the extra, easily aimable, wattage for wintertime, but the roof panels will be a great addition.

Even though I didn't end up going with the 7622, I have a similar (but next size down) unit on a boat, and can recommend just about any Blue Sea product. You could use a 7622 without removing the LVD, I think (would have to run it through my mind a bit more to be more definitive). But I don't see any real reason to keep the LVD in "modern times" -- unless you just want to. That's always a valid reason.

[Roly]

Thanks for the response. Some time passed since then, sorry... I been wrapped up in overseeing an estate then house sale since my Ma passed away recently. She had a good run, was 98.

I just finished up the 200 watt roof panels, with Bogart industries controller and monitor and cheap batteries. Seems to work. I find the 1315 clacking regardless of alternator, solar, or P.D. charger or combinations thereof as a source. Maybe the starting battery could be replaced, but seems strong. I would like to know why you skipped the 7622. Could it have dropped in and still been overridden by the cab ceiling switch? It looks a bit bigger than the 1315.

What switch plus indicator light? located on the fender?? Could one use a 1,2,both,off switch? (Perko?)

Did you make a schematic of what you did for the LVD ripout? (We used that term at Mare Island for the initial phase of a submarine overhaul.) Did it make the cab ceiling switches obsolete? I have done plenty of cabling, wiring and re-wiring, but electrical engineers always did the designing. (And redesigning when the electricians showed them how it won't work.)

Now that I have the solar panels secured to the roof, I can drive to a shop to get the cab A/C repaired. Then up the Oregon coast to Puget Sound on a house hunting trip.

Roly

[Blue~Go]

Hi Roly,

Fun to see your Vega. I'm a fellow sailor and have always liked them. All that nice sapele, plus the super comfortable cockpit coamings. And they sail well

I will come back later this evening and give you my thoughts, such as they are. Just saw this now and thought I would respond.