question

It seems to be complaining about too much inrush current. Out of interest, what happens if you remove the jumper off the BP100 to disable it, then turn the main switch on before replacing the jumper plug?

With the remote jumper removed the BP100 doesn't seem to power on. When I connect the jumper it cycles on the same way as when I would connect battery power in the video. It shows the fault after a few seconds.

I was on the train earlier so I couldn't do much research.
It's difficult to see exactly how you have everything set up, but point number 1 of the installation manual says: "Voltage drop over a long or undersized cable between battery + and the BP may result in a short circuit alarm when starting up the load or unexpected shutdown." This seems to describe you problem precisely. Please could you check that you don't have too much Voltage drop especially between Battery + and the BP100. Check that all of your terminals are tight and your terminations are good. You have a few links and busbars in the path, are they appropriately sized etc.

Thanks for the reply -- I have about a 4.5' length of 2/0 cable from my batteries over to the BP100. This should be an acceptable voltage drop especially at low load (the BP100 shows the error with next to no load on the system). All of the connections are tight and when bypassing the BP100 it all seems to operate fine so far, but its worth checking anything right now so I will loosen, check, and tighten each connection.
Do you know of a way to bench test the BP100 to see if it is faulty? Or maybe for the $60 I should just buy another and drop it in to see what I get. I have to complete this project very soon so I'm trying to come to a solution quickly. Thanks for the help!

To rule out the Voltage drop issue that I mentioned before, you could move the BP100 right close to the battery and see if it still comes up with the error. Even though you say you have minimal load, still worth a try for zero monetary cost.

It would be a bit tricky to physically move the BP100 any closer to the batteries with the space and cables I have available. I have measured the voltage drop with all loads turned off, and again with my fridge, fan, and lights on which is about 6-7A of power draw -- the maximum power drop is .03v between the batteries and the distribution blocks near the BP100. Does that help address your question?

I had also posted a question about not being able to get to the "D" in Program Mode to verify the voltage the BP100 is set to, but haven't gotten a response there. Do you know how to access that? I can use Program Mode to access numbers 0 through 9, and letters A, B, and C, but it does not ever display D, it just cycles A, B, C, A, B, C, over and over. I'd like to verify that it is in 12v mode but haven't been able to do that.

I'm not too sure how it thinks / calculates a short circuit, maybe it's a round trip calculation, like a Voltage difference between the two main posts. The manual says somewhere I seem to remember about installing it a close to the battery as possible, so I suggested that to try and rule out the unit being faulty. It's be a waste to buy a new one and find the same problem again.

I did see your question about the programming issue. I didn't answer because I don't know. I have a feeling that d is only accessible when the jumper on the remote terminal is out, but I'm not certain.
However, I'm pretty sure that the battery Voltage setting is correct otherwise you'd be getting undervoltage errors E3.

Thank you again for the help -- I'm not sure if you work for Victron or not to be honest, but appreciate you taking the time to work through this with me. I do wish I could move the unit closer but to be honest after two nights of testing every related wire and load that could be linked to the 'load' cable on the out post of the BP100, I still have not identified any short circuit. I went ahead and ordered another BP100 just to test and see if it resolves the issue. If it does, great. If it doesn't hopefully I will be able to return it, and I'll probably cry myself to sleep.

Sorry, I don't work for Victron I'm afraid. I'm just offering some advice in the community spirit.
I'd be very interested in the outcome of installing a new BP100. Please keep us updated!

We have fitted a few of these. The cable length to the battery is quite critical for an inductive load.

The small black negative cable supplied with the unit is approx 500mm long. That is the maximum length that Victron recommends to be from the battery.

In saying that, If you need to go longer, we had best results keeping the wire size above 2.5mm2 for the negative wire.

Some of our cable supply runs were 10metres or longer of 2.5mm2 twin cable. these fed through a fuse to the battery protect, then directly into an Orion isolated DC/DC converter. About one in every 20 installs had the same issue as yours. We were only drawing about 5 amps max though.

Try to keep the positive and small negative cable to the battery protect a similar length from the battery if possible.

Our local dealer was very helpful as well

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Hi Bryan,

Same problems with BP-65.

I'm using the Victron BP-65 inside my EV in order to protect the 12V lithium batterie (LiFePo4) and I have exactly the same problems you described here for BP-100.

Error E1 (short circuit) occurs, when releasing the BP without having a real short. And I also was able to activate the system, when bridging the IN and OUT terminals via a fused cable and then switching on the BP-65 via Remote-IN, like your scenario 2.

My configuration:
Battery +12V --> fuse --> BP-INPUT (over all length about 10 cm)
Battery 0V --> BP-GND (black Victron cable, complete length)

How did you solve the problem in the meanwhile?

Best regards, Georg