Bad BIM, rolling anyway

[16ACE27]

Not sure this is the place to do it, but I re-ran the Judge method to test my battery isolation.

Everything off, no shore power, some rest: 12.8 Chassis, 12.8 H

Ignition on, master switch off, emer start button depressed, NO SOUND (maybe didn't hold it long enough?)...twice. same with master switch on.

Master off, headlights ON, Foglights ON, fan ON:
12.22 Chassis, 12.43 House (why should house move at all)

All OFF:
12.73 chassis, 12.78 house

Master ON, inverter ON, furnace ON:
Chassis 12.45, House 12.45
(Same with Inverter OFF).

So, Inverter is before master switch, looks like house and chassis are on same circuit, not isolated.

What else should I try? Voltage drop at house batteries on engine start? Disconnect chassis battery entirely and see if it'll start on house batteries without emergency start depressed? (That would mean BIM works and switch is bad?)...

Thanks.
We are 3.5 weeks, 2000 miles out with no issues but haven't boondocked yet (partly because of the heat).

Don't want to engage an RV tech on this yet..

And again, thanks! Any input is helpful

Didn't you START this thread over 3 weeks ago stating that your house and chassis batteries are permanently tied together? Today's test just confirmed what you already knew.

 

[CRPerle]

Excellent point.
As long as all I have to do is not run down the chassis battery by "paying attention" then nothing really.
I do like the systems to work as intended though and isolating batteries seems important...
It's also a good exercise in understanding my basement wiring, which isn't made easy by Thor that's for sure...
But, yeah, if I can't hurt anything, then why bother, right?

 

[ducksface]

I am campaigning for
quiet enjoyment
Of an rv
Instead of
Frantic 'not quite right' manic repair.

Too many here try to thrust their stigmas on others as irrevocable have-to doctrine.

Single psi
Tenths of volts
Ounces of tow ratings
Trans temps
Not using the toilet
1/3 full water tanks
BIM
Excessively long wires
Sawdust behind the drawers.

Any mass hysteria ever ever ever
Started with a single hysterical person.


I pick my demons more carefully.
When 'why bother' becomes a real bother, I'll bother.

https://www.amazon.com/gp/aw/d/B004HGTXUQ?psc=1&ref=ppx_pop_mob_b_asin_image

https://www.amazon.com/gp/aw/d/B09W5SFK6L?psc=1&ref=ppx_pop_mob_b_asin_image
(Helps you and others)

 

[16ACE27]

Excellent point.
As long as all I have to do is not run down the chassis battery by "paying attention" then nothing really.
I do like the systems to work as intended though and isolating batteries seems important...
It's also a good exercise in understanding my basement wiring, which isn't made easy by Thor that's for sure...
But, yeah, if I can't hurt anything, then why bother, right?

As discussed earlier in this thread there are more detriments to having the two battery banks permanently tied together. You ordered a new BIM to "fix" the issue but as far as we've seen you haven't even located the BIM to disconnect wires and do some real troubleshooting and/or verify you really have a BIM. For all we know you have a BIRD and Trombetta solenoid which has welded itself closed.

 

[CRPerle]

As discussed earlier in this thread there are more detriments to having the two battery banks permanently tied together. You ordered a new BIM to "fix" the issue but as far as we've seen you haven't even located the BIM to disconnect wires and do some real troubleshooting and/or verify you really have a BIM. For all we know you have a BIRD and Trombetta solenoid which has welded itself closed.

Well, that's not true in the slightest.
I have a BIM160, as I have stated. I am in touch with Precision Circuits, as I have stated.
I have just now tested the voltages at the BIM160 per their tech support and determined that I should replace it with the BIM160 I bought before I left on this voyage 3 weeks ago.

I'm not at all sure where your skepticism cones from, but it's not me. I've been as transparent as possible and feel like these emotions are misdirected.

All I'm trying to do is figure out this rig, fix what I can, and avoid any major mishaps that can be avoided, knowing that is not all of them.

I'll ask again, what specifically is so bad about rolling with a BIM that is "always on" besides accidentally running the chassis battery down while boondocking?I'd really, really like to know.

The new sealed lead acid group31s that I put in last month are not going to overwork the alternator nor be overcharged by them. So, what's the risk? (Not that I'm not planning to swap the new one as time allows).

Thanks!

 

[ducksface]

Nothing.
The answer is nothing.
Nothing extreme happens.

If, as accused, Thor often wires a bim backwards
This means
There are 100,000 or so coaches that have been, and are currently, wired this way.

I run both batteries down when the coach goes down.
I jump them with the above linked jumper and I'm down the road.
I wired my new bim as was the old bim, maybe backwards.

No hair lost, no meds needed, I just jump it if I screw up and forget to turn something off.
So far it's been twice, both in front of th same friends house on the only two times I've parked at their house.

No fires, no dires.

 

[16ACE27]

I'll ask again, what specifically is so bad about rolling with a BIM that is "always on" besides accidentally running the chassis battery down while boondocking?I'd really, really like to know.

See post # 28 in this thread or read this from Optima batteries:

We would strongly discourage anyone from connecting batteries in series or parallel applications, if the batteries are not identical in age, size and type. It sounds like your batteries are different in each of those ways. Different brands of batteries can have different charging and discharging characteristics, with some accepting a charge or delivering current faster than others. That can be true even if the batteries are the same size. Different types of batteries (flooded or AGM) also can have different charge/discharge characteristics. When you connect two or more batteries that don't charge and discharge at the same rate, one battery will probably end up overcharged and/or one battery will end up undercharged. Neither is a scenario you want to have happen to your batteries, as it will probably shorten the lifespan of both and could create a potentially create a dangerous situation, if one battery gets severely overcharged.

The same is also true of batteries that are identical in every way, except that one battery is older than the other. As batteries age (or get used), their charge/discharge profile changes. As such, they essentially charge and discharge at a different rate a year later, than they did when they were brand-new. That means you shouldn't connect batteries together that aren't the same age or haven't been used in the same application since they were new, even if they are the exact same make and model.

Unfortunately, that means when one battery in a bank of two or more batteries needs to be replaced, they should all be replaced at the same time. That doesn't mean the other functioning batteries should be discarded entirely, but they should not be used in an application that has batteries that differ in age, size or type. For some marine and RV applications that use a lot of batteries, it may make sense to isolate a larger bank of nine batteries into three smaller banks of three batteries, instead of connecting them all together. That way, if one battery goes bad, far fewer batteries need to be replaced.

 

[ducksface]

'Strongly discourage'
Is not 'void your warranty'
Void your warranty is a definitive.
Strongly discourage is a sales device.


Can have
Probably
some
Can be true (not IS TRUE)
Want
Could
May Make sense


These are political words
They are not defining words used when definite things are irrefutable.

They mean the potential, no matter how slight, is exaggerated as greatly as we dare put in print.

I'm not saying to do it
But
They sure aren't saying to definitely not do it.

Sales.
'I guess I'll have to buy all four new batteries now due to me needing just the one new battery'

PERCENTAGE OF BATTERY LIFE LOST AND CHANCES OF LIFE LOST IS HANDILY NOT STATED IN THEIR
'STRONGLY DISCOURAGE'
document.

(I'd have a completely different view had they said
'We will void your warranty if you mix batteries')

That document is the type of innuendo I'd like to crush.
It does not say anywhere in it not to do this or disaster is afoot.
It's a marketing piece. It will sell four fresh batteries because you needed one battery for your bank.

It relies on laboratory folk strangling out every possible amp.
I do not need to strangle out every possible amp so I can use those lab tests in my marketing material. They do.

Your
Mileage
May
Vary
Was instigated as a phrase to combat the lab folk lies.
(We all know this)

 

[CRPerle]

Thanks.
Somehow I missed post #28. These are busy times.
All batteries are FLA and new this spring. The BIM puts them on the same circuit for charging, so it can't be that terrible to do.
That said, I should be able to replace the BIM in the next few days, and should know a lot more then...

 

[CRPerle]

new BIM installed! And...

With the help of a knowledgable engineer friend, I was able to swap out the old BIM for the new one this morning and do some testing. Here is what we learned.
Bench tests with dual power supply:
Old BIM was stuck closed, never clicked (field or bench)
New BIM "clicks on" (closes) on SIG (grounded or hot) and on charging voltage in Batt A.

field- House batteries showed voltage drop on ignition of engine.
All batteries at equal voltage (as usual).
Old BIM was mis-wired with house going to Batt A and chassis to Batt B, BUT other wiring was seemingly correct (continuity with SIG wire at battery box to "emer start button" at dash). NOTE: chassis wiring disappears from battery box but does a quick U-turn and returns before going to any other systems as earlier suspected.
Random 15A fuse/wiring going to Batt A terminal. Left in place. God knows what that goes to.

the 2 sealed FLA grp 31s are in parallel, but some systems are served off one terminal, and others of the other. As I understand, all services should be fed off one pos. terminal, preferably with a bus bar. Will deal with that later, maybe when I install the shunt battery meter I just bought.

There is a 100A fuse with 2 cables (leveler (for sure) and controller/master switch/house draws?), a 50A fuse (slides?), and a 750Amp (!) fuse, which I guess is for the 1800W Inverter and is just wired up for a much larger unit? Any input appreciated...

Results:
finally saw a meaningful voltage difference between Chassis and House! Now waiting to see if some gremlin blows the new BIM. Once the need to cool the house is met, I can disconnect shore power again and try Judge's method to see if the new BIM indeed isolates (I think it does), and also check if the BIM clicks when the 'Emer Start' is depressed (per PC tech support, I think it will) and also look for a voltage drop upon starting the engine.

Thanks to all who helped move this along over the last couple of months. I'm too much of a skeptic to think it's all good and over, but I'll be very happy if proven wrong.

Now, does anyone know why my LCI- Leveling controller- flickers on when driving in the rain. Seems not ideal.

Thanks!!

 

[16ACE27]

With the help of a knowledgable engineer friend, I was able to swap out the old BIM for the new one this morning and do some testing. Here is what we learned.
Bench tests with dual power supply:
Old BIM was stuck closed, never clicked (field or bench)
New BIM "clicks on" (closes) on SIG (grounded or hot) and on charging voltage in Batt A.

field- House batteries showed voltage drop on ignition of engine.
All batteries at equal voltage (as usual).
Old BIM was mis-wired with house going to Batt A and chassis to Batt B, BUT other wiring was seemingly correct (continuity with SIG wire at battery box to "emer start button" at dash). NOTE: chassis wiring disappears from battery box but does a quick U-turn and returns before going to any other systems as earlier suspected.
Random 15A fuse/wiring going to Batt A terminal. Left in place. God knows what that goes to.

the 2 sealed FLA grp 31s are in parallel, but some systems are served off one terminal, and others of the other. As I understand, all services should be fed off one pos. terminal, preferably with a bus bar. Will deal with that later, maybe when I install the shunt battery meter I just bought.

There is a 100A fuse with 2 cables (leveler (for sure) and controller/master switch/house draws?), a 50A fuse (slides?), and a 750Amp (!) fuse, which I guess is for the 1800W Inverter and is just wired up for a much larger unit? Any input appreciated...

Results:
finally saw a meaningful voltage difference between Chassis and House! Now waiting to see if some gremlin blows the new BIM. Once the need to cool the house is met, I can disconnect shore power again and try Judge's method to see if the new BIM indeed isolates (I think it does), and also check if the BIM clicks when the 'Emer Start' is depressed (per PC tech support, I think it will) and also look for a voltage drop upon starting the engine.

Thanks to all who helped move this along over the last couple of months. I'm too much of a skeptic to think it's all good and over, but I'll be very happy if proven wrong.

Now, does anyone know why my LCI- Leveling controller- flickers on when driving in the rain. Seems not ideal.

Thanks!!

Are those FUSES or breakers?

50 amp breaker is for the house load buss
100 amp breaker is for the leveling system and generator start/run.
the 750 amp fuse/breaker has to be for the inverter, but way oversized for an 1800 watt inverter, which should be 350 amp at most (assuming a surge capability of 3600 watts and battery voltage of 11 VDC and wiring to handle a constant 1800 watts).

 

[PS89]

Random 15A fuse/wiring going to Batt A terminal. Left in place. God knows what that goes to.

Dash radio. It's ALWAYS HOT from that connection.

As I understand, all services should be fed off one pos. terminal, preferably with a bus bar.

Preferred, yes. Necessary, no. It will work either way.

 

[CRPerle]

Thanks...yeah, breakers. Except the 750...might he mislabeled but it's big, as are the wires, biggest on the rig...can only think it's wired to handle a bigger inverter...

 

[CRPerle]

Thanks...that's interesting, I wonder if it's always hot, BUT, funnily enough a shop told me they wired the dash radio to the chassis battery...that wire connected to Batt A may serve nothing now, if true...

Since everything seems to be "working," I'm disinclined to mess with stuff too much until we are not in touring mode.

 

[Bob Nodine]

Thanks...that's interesting, I wonder if it's always hot, BUT, funnily enough a shop told me they wired the dash radio to the chassis battery...that wire connected to Batt A may serve nothing now, if true...

Since everything seems to be "working," I'm disinclined to mess with stuff too much until we are not in touring mode.

On our Class C the dash radio is powered from the house batteries and not the chassis battery. I assumed that is so the dash radio would operate while camped as there are speakers in the living area. As configured from the factory our chassis battery was not being charged from shore power so I guess Thor thought we campers would run down the chassis battery playing the radio in a camp site. I changed that so now our chassis battery is charged when ever there is a charging source from anywhere.

 

[CRPerle]

Thanks. Yes, that is how I think it is "supposed" to be wired. My shop didn't know that though. They were more a truck repair than RV shop.
So, they re-wired it to the chassis. Oh well. "Mistakes were made."

 

[CRPerle]

Battery Compartment Schematic

So, TMC came through with a diagram that looks almost exactly like what I see.
Almost.
I attached it; hopefully you all can see it (still a newbie here).
Pretty sure this wraps 'er all up.
Thanks everyone for the replies. All of them. This forum has been very helpful all the way around.
(yes, new BIM seems to be functioning properly, and the flickering LCI may have also been resolved in the process, and the shunt monitor (now in hand), will just have to wait)

SITE TEAM EDIT:

Copyrighted attachment removed (Community Rules Violation)

Image in PDF is essentially the same as posted in post #31 in this thread (except series vs parallel: 6 vs 12 VDC; battery connections).

 

[Scubawise]

CRPerle thanks for your deposit dive.
I uses a multi meter on my bim 160 & heard clicking when I touched terminals.
Something woke up! No clicking before
9 days camping test. Bim working 100%

Dropped coach to 11.9 with inverter load microwave & chassis held 12.8

CRPerle

 

[CRPerle]

You camped for 9 days without air conditioning?
Where?

Congrats on a working BIM, we'll be boondocking somewhere soon too!

(Microwave is not on the 1800W inverter circuit for some reason...)

 

[16ACE27]

You camped for 9 days without air conditioning?
Where?

Congrats on a working BIM, we'll be boondocking somewhere soon too!

(Microwave is not on the 1800W inverter circuit for some reason...)

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