House Battery Blues?

[Flux]

They sure can and most do it that way to avoid running unnecessary large cables back and forth under the body.

[boywonder]

Originally Posted by capnkurt

Hey Mike, sorry to hijack the thread here, but I figured this is a question that you probably would want answered in case you find that the isolator has become faulty...so, can these battery separators that Boywonder linked to be located under the hood? Specifially, if someone were to be interested, let's say, in mounting it in exactly the same spot at the original surepower isolator on the radiator core support/front bulkhead?

capn

The two shown above are water ingress rated at IP67 and IP66 respectively, so yes you can mount them under the hood.

[capnkurt]

Thanks guys! I'll start a new thread with more questions.

capn

[MountainBikeRoamer]

Originally Posted by capnkurt

Thanks guys! I'll start a new thread with more questions.

capn

I'm stoked on learning about all this stuff!
The advantages of the separators vs. isolators do sounds worth the investment, based upon what guys have been stating in this thread so far.

Can I ask another question:
In the quest to track down the possible parasitic shorts within my electrical system (if the battery ends up checking out okay) -- is there a simple, stand-alone means of testing the integrity/performance/health of an older-style battery isolator, like my system (and I believe capnkurt's system) still has?

Or, put more articulately.....
If an isolator is "going bad," and has begun to behave in a compromised fashion, how is that assessed exactly? Will it manifest solely in a "less than perfect" switch action to open/close the house battery circuit? Or (and?) does it also begin to act as a power-thirsty (heat-generating) parasitic battery-eater just by itself? Does one simply perform continuity tests through the isolator in open/closed operation cycles to make sure it is truly isolating the house battery? (And also fully closing the circuit when required, to deliver proper current for battery charging?)

Thanks again, Electrical CamperVan Wizards.

[Scalf77]

Below I have attached instructions for testing your isolator. Basically you have the possibilities of the circuits opening up, which does not look like the case for you. If the Diodes were shorted you could be seeing drain from the house side. A very easy test is to check voltage on house , if you turn on headlights and see the voltage drop on both house and starting side you I would expect that it is bad. Also you should be able to measure voltage on the alternator terminal and then the House batter terminal, you should see a drop in voltage (0.5 to 0.7) from what you are seeing on the alternator.

Also, be aware that when you are done charging the voltage will most likely be higher then your expected 12.8, you will need to remove the surface charge to get a proper voltage reading. You can use one of the following methods

1. Allow the battery to sit for six hours with no load or charger connected
2. Apply a 25 amp load for three minutes and wait five minutes
3. With a battery load tester, apply a 150 amp load for 10-15 seconds.


Instructions for testing a isolator,
INSTRUCTIONS FOR TESTING A SURE POWER ISOLATOR WITH OHMMETER*:
1. Remove all wires from the isolator.
2. Using a needle movement ohmmeter RX-1 scale or a digital ohmmeter diode scale, hold the Red* probe on the terminal "A" and with
the Black* probe touch terminal #1 and #2, and the "E" terminal for 3A isolators (group 2), and the "R" terminal for (group 3) isolators.
A good isolator will show a current flow from "A" to #1, #2 and "R", and no current flow to "E".
3. Next, hold the Black* probe on the "A" and with the Red* probe touch terminal #1 and #2 (terminal "E" and "R", if used). A good
isolator will allow no current flow from "A" to #1, #2 or "R" and will show current flow from "E" to "A".
4. Hold one probe on the aluminum heat sink, being sure there is contact by scratching through the protective coating. Then touch
with the other probe, terminals "A", #1, #2 (the "E" terminal for 3A isolators [group 2] , the "R" terminal for group 3 isolators). A
good isolator will show no current flow.
5. Colored terminal indicates "E" post on group 2 isolators and "R" terminal on most group 3 isolators.
*On some import ohmmeters, the red and black probes are reversed for these tests.
**If using a digital ohmmeter, a diode scale MUST be used.


-greg

[MountainBikeRoamer]

Hi guys - just wanted to give you a brief update.

Monday rolled around....as it does....and I ran out of time to do much more work with the van for a couple days. Haven't yet tested the battery further, apart from monitoring it's state of charge over the last two days. (It's sitting on my garage workbench, unhooked from everything.)

It happily settled in at 12.60 volts.
Seems to be pretty stable.(in the van, I was seeing it drop to 12.5 or 12.4 sometimes overnight, without any electrical devices or lights being used whatsoever.) I will be cracking the ports tonight to check the water levels (picked up a gallon jug of distilled water and a turkey-baster (seemed like a great way to add water to a battery in a precision manner.)

So, probably tomorrow:
Planning to start with a quick round of some investigatory current testing next ---- since the initial symptom was abrupt house-battery voltage drop *right when flipping on any of the LED lights.*

My dad suggested:
Start by doing an in-line (series) amperage check with the battery still on the workbench....with the ammeter placed in series with one of the same LED bulbs that are installed in the van --- thus, to get a "baseline" true, measured current draw for one of those lights. Checking also, after perhaps ten minutes of running that one light, to see if the battery voltage dropped significantly like it was doing in the van under the same LED-light-operation-initiated scenario.

And then ---- take the same LED bulb, reinstall it in the van (in its light fixture), reinstall the house battery in the van, hook the ammeter up in series with one of the battery cables, and then try flipping the same lightbulb on. See if there's a big discrepancy or not.

If no significant difference in the two amperage measurements....then I guess I'm immediately back to further battery investigation (and other shorts/grounding issues with the RV system circuits. Hunting for a short. Eyeing perhaps the charging circuit grounding in particular, as gooseberry initially mentioned.

But it really does seem that the battery charges reasonably adequately in the van, it needed next-to-zero time on the 110volt (10 amp) bench charger to indicate it was full at 12.84 volts the other night. (Settling to 12.7 volts later that night....and then 12.63 the next morning. One day later and still happily showing 12.60 volts.)

Of additional note relative to the charging system, however:
I went and spent some time looking at what power supply/house battery charger my van has ---- and it's a "Todd Engineering PC30." Original-SMB-installed equipment from 1995. I then did some googling and found that you guys have discussed that unit on here briefly/recently before, and didn't have the highest opinion of it. Wondering if that's a component (regardless of what my current issue proves to be) that I would be wise to consider upgrading sometime soon.

Your previous SMBF discussion about the PC30 (a very short one.):
http://www.sportsmobileforum.com/for...rce-11128.html

The PC30:


Cheers --- !

[boywonder]

One thing to note when using your multimeter in current mode...if you wire it in series with the battery and flip a few things on and exceed 10 amps you'll blow the fuse in your meter...requiring you to take the back off of the meter and replace the fuse.....

I just read the thread on the Todd engineering PC30.....it's a dumb charger......

Have you used shore power (Tod charger) to charge your house battery?

[MountainBikeRoamer]

Originally Posted by boywonder

I just read the thread on the Todd engineering PC30.....it's a dumb charger......

Have you used shore power (Tod charger) to charge your house battery?

Never as an intentional process; only on the evenings before we go on a trip somewhere.

And even then, it's still not an on-purpose thing to charge the house battery, it's merely a nice by-product of the real reason I plug it in: to power the 2-way fridge (Norcold propane/110AC) and get it nice and cold by the next morning. (And also to happily run all the van's interior lights simultaneously --- making it easy to see, late at night, when we're usually packing up the van.

I have definitely noted (this is purely anecdotal) that the measured voltage at the battery the next morning (after unplugging from shore power) seems to be a tad bit "healthier" than when we charge the battery via the alternator (maybe by one-tenth of a volt or two?) but have never made a point or really studying/measuring it.

Do I need to dramatically rethink my house battery maintenance routines?

Honestly thought (when I bought this van, and read the cheerful, super-simplified vintage literature that Sportsmobile had written back in 1995) that the house battery was set up to be just as maintenance-free as the starter battery under the hood of any modern car.....but I can see increasingly that it's more involved than just letting the battery get charged whenever I happen to drive around.

[86Scotty]

If you're not tired of spending money yet you can't go wrong with updating that old power converter to modern inverter/charger. Larrie has a great one (my old one) for sale. They aren't cheap but have huge advantages. It's what came in more modern Sportsmobiles.
If you don't need the inverter part you can't go wrong with an Intellipower converter.

[MountainBikeRoamer]

Originally Posted by 86Scotty

If you're not tired of spending money yet you can't go wrong with updating that old power converter to modern inverter/charger. Larrie has a great one (my old one) for sale. They aren't cheap but have huge advantages. It's what came in more modern Sportsmobiles.
If you don't need the inverter part you can't go wrong with an Intellipower converter.

Hey! Awesome.
Thanks for clueing me in on that.
I'm interested! (Well at least to learn more...)

Realistically (from my own perspective, and perhaps from that of anyone who reads this thread in the future) --- since it seems that "SMB things worth having" sell pretty fast here on the forum....can I ask which make/model it is that Larrie has for sale? And price, if you (or Larrie rather) have announced one?

If that one doesn't prove to be a match for my needs, I'm definitely still in the hunt (it sounds like now) for a better, more modern power supply/charger, so I'll be very appreciative to learn which one(s) are most widely (or happily) in use by you guys.

(By the way.....haha, not sure if I've grown tired of spending money yet. As Sportsmobile peeps, are we even **allowed** to think about that?)

I was musing the other day that the real meaning behind the Sportsmobile acronym "SMB" ought to be publicly announced for what it truly is, "Spend More Bucks."