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Electric Step working with house batteries off
Up until recently, I have been leaving the house batteries in my LD on and the other switch set on Dry Camp when I leave the RV in storage after a trip. I had to replace the main engine battery, so I had a cut off switch added for the engine battery.

When I left my RV a couple weeks ago, I had both switches set to off, and the steps retracted just fine when I closed the RV door, which is what one would normally expect.
Yesterday, I went to check on the RV, and the steps didn't extend when I opened the door. Not fully understanding things, I switched both cutoff switches to on, and the steps worked normally.

When I left this time, I cut both switches to off and the steps retracted when I closed the door.

My question, which batteries do the steps work off of, and why would they continue to work for a short period of time after the battery cut off switches have been flipped?

Re: Electric Step working with house batteries off
Reply #1
Our steps work off of the house batteries except when the ignition key is on.
Ross Taylor
2017 MB

Re: Electric Step working with house batteries off
Reply #2
Hi Rob; Welcome to the FOLD. (Fellowship of Lazy Dazer's). The 'Dry camp' switch on a HPV-22B means you have solar panels, and it  was sunny. The panels, even just one 85 Watt panel, can power the LD's 12vdc needs directly enough to operate the steps.   RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: Electric Step working with house batteries off
Reply #3

Yesterday, I went to check on the RV, and the steps didn't extend when I opened the door. Not fully understanding things, I switched both cutoff switches to on, and the steps worked normally.
When I left this time, I cut both switches to off and the steps retracted when I closed the door.
My question, which batteries do the steps work off of, and why would they continue to work for a short period of time after the battery cut off switches have been flipped?

The electric steps should not move when both the starting and coach batteries are disconnected, unless the rig is still plugged in and the converter is powered up or possibly the solar panels provides power for the steps, when the sun is shining..

If both batteries are disconnected, there is no need to operate the converter.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze

Re: Electric Step working with house batteries off
Reply #4
I experienced a similar issue recently. 

The house batteries were disconnected (via a disconnect switch).  The solar fuse had been pulled.  I was not connected to shore power.  The coach door was open and the step was in the retracted position.  I had disconnected both terminals of the engine battery as I installed a new lithium battery isolation manager (LI-BIM 225) to replace the the original isolator (contactor) in the engine compartment

When I finished the isolation manager install and reconnected the engine battery, to my surprise the coach steps extended automatically.  I did not think the steps would operate with the coach batteries disconnected.

Also puzzling was that when I closed the coach door the steps stayed open.   The steps extended just the one time.

Any ideas as to where the power came from to extend the steps that one time?

Geoff


2015 MB
2021 Ford Escape Hybrid

Re: Electric Step working with house batteries off
Reply #5
Try disconnecting the LI-BIM 225 isolator, it's probably back feeding the 12-volt system.
I'm surprised it would be passing voltage when the engine is off, the LI-BIM is supposed to disconnect if the alternator voltage drops below 13.3V.
Check your wiring, you may not have the LI-BIM hooked up correctly.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze

Re: Electric Step working with house batteries off
Reply #6
Hi Geoff;  As far as I can tell by descriptions of what this BIM is supposed to do,  LiFePO4 Battery Isolation Manager (BIM) | Battle Born Batteries       , it samples voltages from both battery systems to decide what to connect and when. When you reconnected the chassis battery, the BIM connected to  sample the chassis battery status, and the steps extended, (because its internal contactor was closed). By the time you expected the steps to retract, the BIM had disconnected, deciding to 'isolate' from the chassis battery' like it should. So no problem.
     The step should retract, using the chassis battery when you turn on the ignition.  If you had been using the house batteries heavily and started the engine to drive away, you would still want the steps to retract using whatever power was available. The step (I believe) doesn't cycle continuously as the coach door is opened and closed. both to save energy and 'wear and tear' on the step.   RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: Electric Step working with house batteries off
Reply #7
Quote
When you reconnected the chassis battery, the BIM connected to  sample the chassis battery status, and the steps extended, (because its internal contactor was closed). By the time you expected the steps to retract, the BIM had disconnected, deciding to 'isolate' from the chassis battery' like it should.

Ron:  Your explanation makes sense, but I have not be able to replicate the scenario I described earlier.

There may be more going on;  I do not believe the BIM is disconnecting (reliably) when it should. 

 While testing my wiring hook ups:

1. With the engine off and the house batteries off, I read 12.4 volts on both the coach and engine sides of the BIM.

2. With the engine off, engine battery disconnected and the coach batteries turned on I read 13.3 volts on both the coach and engine sides of the BIM.

3.  With the engine on and both the coach and engine batteries connected I read 14.3 volts on both the coach and engine side of the BIM.

I turned the engine off, and then the BIM made a loud 'clunk'. So I repeated the three steps above.  This time with the engine off and both the coach and engine batteries on I read 12.4 volts on the engine side and 13.3 volts on the coach side of the BIM.  Seems the BIM had finally done what it is supposed to do  with the engine off and disconnected.

Then I started the engine again with both batteries connected and read 14.3 volts on both sides of the BIM.

Then I turned the engine off and took the same readings and got the same results as in steps 1, 2, and 3 above:  the BIM is not disconnecting the two systems when the engine is turned off.

I'll call Battle Born tomorrow.

Larry/Ron;  Thanks.  Appreciate your insights.

Geoff

2015 MB
2021 Ford Escape Hybrid

Re: Electric Step working with house batteries off
Reply #8
I went back and re-read the BIM literature.  I was under the impression that the BIM would only connect the two systems then the ignition was on.  However that is not the case;

From the literature

Senario 1: Engine is "on" with a Chassis battery voltage greater than 13.4V and a Coach battery voltage less than 13.3V

Response: The LI-BIM 225 will connect the batteries for 15 minutes, then disconnect the batteries for a wait time of 20 minutes. After this wait time, a new voltage reading will be taken of each battery. If the voltages remain within the scenario's parameters, the response repeats.

Senario 2: The Chassis battery voltage is below 12.5V and a Coach battery voltage greater than 13.5V

Response: The LI-BIM 225 will connect the batteries for 1 hour, then disconnect the batteries for a wait time of 2 minutes. After this wait time, a new voltage reading will be taken of each battery. If the voltages remain within the scenario's parameters, the response repeats.

The engine is not ON in Senario 2.  Perhaps this is what I've been observing.

Geoff

When all else fails; read the instructions.

2015 MB
2021 Ford Escape Hybrid