Intermittent BIM?

[Land Stitchy]

Ironed out one bug (Nova Kool) and picked up another. At least I enjoy occasional projects.

Main battery BIM charging is intermittent.

The drain on my main battery is well documented in other posts and similar to many other's experience. 1.6 amps drain. Basically 4-5 days before main is dead if I don't stay plugged in. Fusion and other problems..... not the purpose of this post and already on my list to repair.

I am fortunate to keep the coach in my driveway so I check in every evening on systems. I am on shore power constantly so charger is on. Battery switch kept on. I check main and auxiliary battery level everyday. During my checks I can see it running between 13v (charging) and 12.2 volts. Up and down regularly. However, after about 8 to 10 days I see it drop below 12v. Yesterday I noticed the main was 11.7v while aux still 12.8 Got home tonight and main is down to 11.3v.

Here is the trick. Turn off the main battery switch, wait 10 seconds and turn it back on. Give it one more minute and the BIM solenoid kicks in and starts charging main battery.

This is the second time in a month that I have caught it and "rebooted"?? the BIM. If I did not catch it I am sure the main would go completely dead.

Sounds like a BIM replacement. Any other ideas? If it is the BIM can I just change the module on top and leave the solenoid in place? That would appear to be a much simpler project.

[wachuko]

I have my BIM in a box at home... you can have it, just send me a PM with address.

But it takes the same effort to just replace it with a Blue Sea 7622 ACR... Well, the ACR does require a few more steps with having to place a few inline fuses... but it is really an easy install... specially if you install the remote switch close by... (that is, if you want that switch working)

[FlyFishinRVr]

I suggest you follow wachuko’s advice and replace the BIM with the Blue Sea ACR. The “porpoising” that you are experiencing is due to how the BIM functions. It needs to see certain conditions on both sides or it won’t close, and even then sometimes it needs a “kick” to do the right thing as you’ve discovered. The Blue Sea only needs to see a charge source at either end and it closes. Beauty through simplicity. [emoji106]

[Land Stitchy]

Thanks guys. Similar effort to install a better product/solution coming from trusted advisors - enough said. I will do a little searching on this forum on Blue Sea to read up on prior posts to understand the process and the remote switch reference.

I just talked to a person in Miami that specializes in RV Sat TV installs which is another interesting decision matrix. He does all types of RV electrical work so might get him involved in this to knock it out quickly.

[wachuko]

Originally Posted by Land Stitchy

Thanks guys. Similar effort to install a better product/solution coming from trusted advisors - enough said. I will do a little searching on this forum on Blue Sea to read up on prior posts to understand the process and the remote switch reference.

I just talked to a person in Miami that specializes in RV Sat TV installs which is another interesting decision matrix. He does all types of RV electrical work so might get him involved in this to knock it out quickly.

I hope this helps...

http://www.airforums.com/forums/f240...ml#post2083406

[Land Stitchy]

Have not had time to get the Fusion switch in stalled or convert to Blue Sea. Maybe Lewster wants to come to the Florida East Coast?

In the mean time I am back down to 11.3v on Main. Is the "porpoising" something that will correct itself and kick in a charge at some point or should I keep flipping the main battery switch to reboot?

[wachuko]

Originally Posted by Land Stitchy

Have not had time to get the Fusion switch in stalled or convert to Blue Sea. Maybe Lewster wants to come to the Florida East Coast?

In the mean time I am back down to 11.3v on Main. Is the "porpoising" something that will correct itself and kick in a charge at some point or should I keep flipping the main battery switch to reboot?

He is in Naples...pretty darn close to you when compared to other folks looking for his help.

[FlyFishinRVr]

Originally Posted by Land Stitchy

Have not had time to get the Fusion switch in stalled or convert to Blue Sea. Maybe Lewster wants to come to the Florida East Coast?

In the mean time I am back down to 11.3v on Main. Is the "porpoising" something that will correct itself and kick in a charge at some point or should I keep flipping the main battery switch to reboot?

Wow, that's really low. Like, dead low.

First, get it charged up and see if it will even hold a charge. Assuming that works, when not using the coach, pull the quick disconnect down by the accelerator. That will 100% isolate the chassis battery from everything else. A bit of a manual process and a PITA, but given how badly your systems are behaving right now, I think that's the only sure-fire way to keep your chassis battery from further damage.

[LB_3]

Originally Posted by Land Stitchy

Sounds like a BIM replacement. Any other ideas? If it is the BIM can I just change the module on top and leave the solenoid in place? That would appear to be a much simpler project.

We had an intermittent BIM. It ended up being a battery cable that came loose from the thermal circuit breaker downstream of the BIM.

[FlyFishinRVr]

Hey Stitchy, here's a thought from an older post on this subject (sorry, gettin' old and forgot about it). From the factory, the Magnum inverter/charger is set for our Lifeline batteries with the AGM1 setting. This setting Absorbs at 14.3v, Floats at 13.1v, and Equalizes at 15.5v. The possible "gotcha" with this is due to the BIM and it's flawed settings (which unfortunately can't be changed). The BIM needs to see 13.3v in order to close. See the problem? If the house batteries are sitting all happy at 13.1v and never go low enough for the Magnum to enter Absorb mode, the BIM will never see a voltage high enough to close. This could explain your "intermittent" observation.

To test this, set your Magnum to the Flooded battery type. This will Float the house batteries at 13.4v instead of 13.1v, which is still perfectly fine for the Lifeline's and is still within their spec, but that should ensure the BIM closes because it's above the 13.3v that it needs to see in order to do so. Now with the BIM closed, all 3 batteries are connected together (2 house + 1 chassis), so all 3 should get properly maintained. I vaguely remember another forum member giving this a try and it seemed to solve his chassis battery charging issues. Again, sorry I didn't think of this sooner.....

[Titus]

Below is an excerpt on BIM troubleshooting. If it passes these tests then the porpoising is not due to a malfunction of the BIM. (That is not to say that the BIM is designed well, just that it is working as designed.)

Trouble Shooting of Battery Isolation Manager is complicated. It is much easier to check the proper operation.
Operational Testing:

Press Dash Switch:
Relay should audibly click and Voltage from Chassis Terminal to Coach Terminal should be <0.2V. If Not, Check for 12V power from Dash Switch to Ground Terminal directly on Relay. (Do not use a Chassis Ground) If 12V present and Relay does not click or bring Chassis and Coach Battery Voltage close, replace Relay.

Release Dash Switch Start Engine & Turn on Coach Lights or other coach loads:
Wait between 20 seconds and 2 minutes and Relay should click. Voltage from Dash Switch Terminal to Ground Terminal should be between 3.5Vdc to 6.0Vdc. If not check that Chassis Terminal >13.3Vdc, Coach Terminal <12.6Vdc, Ignition Terminal >12Vdc. (Check that Chassis and Coach Battery connections are not reversed)

Turn off Engine Plug in Shore Power & Turn on Battery Charger:
Turn on Head Lights. Wait up to 10 minutes and Relay should click. Voltage from Dash Switch Terminal to Ground Terminal should be between 3.5Vdc to 6.0Vdc. If not check that Coach Terminal > 13.3Vdc, Chassis Terminal <12.6Vdc, Ignition Terminal <2Vdc.

[Land Stitchy]

Thanks guys - really appreciate your time and thought on the response.

On the procedure from Titus - got that a few weeks ago and ran through the tests. Pretty simple and everything worked just fine. Solenoid kicked in under all three conditions as described. I could see the immediate voltage change in the panel. That gave me a good understanding of how the system fundamentally works.

The first few times I noticed the "intermittent" drop was many days after a trip. I noticed the main batteries charging periodically and then after 4 or 5 days the main battery charging stopped. On this occasion I ran the coach for a few hours on Sunday for a short trip and notice already on Monday the low drop in voltage.

I should have taken action when I sent the 11.3 volt post on Tuesday - yesterday the batteries were down to 6v - dead. I turned the main battery switch on and off hoping the BIM would start a main battery charge. No such luck. Battery now dead.

This is a brand new battery install about 4 weeks ago after the last dead battery episode.

LB-3, is that loose battery cable somewhere under the jump seat or some other location?

I am committed to upgrading to Blue Sea and installing the Fusion cut off. Just not enough time (or patience) to do it myself and have not found someone in the Ft Lauderdale/Miami area. If I can bring this battery back I will also start disconnecting at the gas peddle until I get the upgrades.

[wachuko]

Too bad you are not in Orlando... we could have done it over a few bottles of water and a few hours over the weekend. But I am not doing a front switch install again... that was a lot of work... switch would have to go close to the ACR, lol.

[FlyFishinRVr]

Originally Posted by Land Stitchy

I am committed to upgrading to Blue Sea and installing the Fusion cut off. Just not enough time (or patience) to do it myself and have not found someone in the Ft Lauderdale/Miami area. If I can bring this battery back I will also start disconnecting at the gas peddle until I get the upgrades.

See my previous post. Get the battery replaced and set your Magnum to Flooded and see if that fixes things, at least for the short term so you can use your coach. For the long term, by all means find someone to do the work for you (totally understand not having the time!).

[Titus]

What does the ACR switch do, and is it something that you have to use frequently? While the BIM may not be very useful for some/many of you, I have not had any battery charging concerns since upgrading to 200W solar and an MPPT controller. We seldom connect to shore power when out traveling, but usually drive for several hours every day. And, perhaps most importantly, we do not have the Fusion and GT power-pig refrigerator and freezer.

Despite our BIM working OK for us, I am not adverse to switching to the Blue Sea ACR. The main reason I have not done so thus far is being scared off by wiring the switch. (That and having to remove the lounge seat back and cushion again. I think I am wearing those threads out!)

[Land Stitchy]

Sorry FlyFish - meant to include your thought as well. I will definitely look at changing the settings.

[FlyFishinRVr]

Originally Posted by Titus

What does the ACR switch do, and is it something that you have to use frequently? While the BIM may not be very useful for some/many of you, I have not had any battery charging concerns since upgrading to 200W solar and an MPPT controller. We seldom connect to shore power when out traveling, but usually drive for several hours every day. And, perhaps most importantly, we do not have the Fusion and GT power-pig refrigerator and freezer.

Despite our BIM working OK for us, I am not adverse to switching to the Blue Sea ACR. The main reason I have not done so thus far is being scared off by wiring the switch. (That and having to remove the lounge seat back and cushion again. I think I am wearing those threads out!)

One of the reasons I recommended the Blue Sea ACR is because the remote switch has 3 functions:
On - force the ACR to close
Off - force the ACR to open
Auto - let the ACR decide what to do based on the presence or absence of a charging source (this is just like the BIM's operation)

That last one is where you will likely keep it 99% of the time. Just like the BIM, let it do its thing. It also has a built in LED to let you know it's status. If the LED is on, the ACR is closed. If it's off, the ACR is open. Easy peasy.

[FlyFishinRVr]

Originally Posted by Land Stitchy

Sorry FlyFish - meant to include your thought as well. I will definitely look at changing the settings.

No worries. I just wanted to make sure you saw it because that could make a quick and easy fix that will allow you to get back to enjoying your coach without battery worries. When you get the time, rip that nasty BIM out by it's dangly little wires and put something better in there.

[Land Stitchy]

Got home tonight and checked battery level. BIM never kicked on and main was down to 4.7V, still a heart beat? Aux batteries at the normal 12.8 to 12.9v range. Thought I might be able to save the main battery by connecting an outside trickle charger - just trying to avoid the PITA of swapping another battery. Storms in my area so had to turn on inside overhead lights due to darkness. Rain and dinner caused me to leave coach for an hour with lights on but before connecting the trickle charger.

When I came back I started connecting the charger leads to the battery terminal. Charger was not plug into AC yet. Then suddenly the solenoid kicked on, Fusion booted up and I could see 12.9V going to the main battery.

Certainly connecting the clips of a battery charger (not powered on) would not cause this the BIM to kick on so I am assuming that by leaving the lights on inside the coach I dropped the aux batteries to a level that caused the BIM to kick on and start charging both. You guys agree? Is there any hope bringing back a battery that was down to 4V or is that a lost cause?

I changed Magnum over to FlyFish recommended "flood". I also recorded all the other settings in case the prior owner got in there and messed it up:

AC in 30 amps
Search 5 watt
Batt AHRS 200
Battery Type flooded (was AGM1 before I changed it)
chg rate 50%
LBCO 11 vdc
VAC drop 100 vac
pwr save - on
equalize - disabled
charger float
power on - norm

Do all these other settings seem right?

[FlyFishinRVr]

Originally Posted by Land Stitchy

AC in 30 amps
Search 5 watt
Batt AHRS 200
Battery Type flooded (was AGM1 before I changed it)
chg rate 50%
LBCO 11 vdc
VAC drop 100 vac
pwr save - on
equalize - disabled
charger float
power on - norm

Do all these other settings seem right?

Personally I have mine set for a 100% chg rate (factory default). I'd rather charge my batteries faster.

Regarding the "deadness" of your existing battery, the only way to really know is to pull it out and take it to an auto supply store that can load test it for you. Chances are it's toast, but it's probably worth a try.....