question

mocat avatar image
mocat asked

Generator startup and stop from BMV-712

Hi all need some help I have a Quattro 48/8000 and a bmv 712 great products serving me well, but in the interest of longevity for my expensive 215amphr victron AGM battery’s I would love for the genset to remote start at say 49.5 volts and shut down when it charges to say 57 volts..... simple you would think using the BMV relays NC NO but Kohler seems to put a spanner in the equation by complicating something that you would surmise is a simple thing to do my Kohler generator is a marine model kohler 9efkozd https://www.manualslib.com/products/Kohler-7-9efkozd-3799387.html

with a digital control module that prevents overvheating low oil pressure shut down and zillion other things, I also have a Kohler remote switch Part Number: GM32335-KP1 https://citimarinestore.com/en/index.php?controller=attachment&id_attachment=2172

at the helm with hr meter not a toggle but more of a button type you press it and release it to start and push it again to stop so I’m thinking it’s a pulse of sorts that takes place to start stop gen set sent to the control board one would think the helm switch is where you would make the connection to the BMV 712 for ease of wiring because basically there beside each other from what I read in the manual for the remote helm switch wire # 4 is start and wire # 3 is stop and wire # 7 Is neutral is it possible to get the BMV to pulse or am I missing something as you would think with the tens thousands of these units that are sold this would be a common necessity for seamless operation.
i have searched the forum for a answer to this issue and I can only find something similar for a Onan Cummings brand gen set.

I just don’t want to get this wrong because I don’t want to damage the control module on the genset as I think it’s worth something like $2k and I’m sure this would of been done a zillion times before and I might add the people at Kohler in Australia have just handballed this all over the ship to no avail.

Thanks in advance

Michael james

BMV Battery Monitorgenerator start on soc
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

4 Answers
JohnC avatar image
JohnC answered ·

Hi @mocat

You may not have a GX box, but there's still a little left in the Victron arsenal: This is a summary, but there's links for more info: https://www.victronenergy.com/live/auto-generator-start-stop:start

If you can't sort what your Kohler needs yourself, perhaps a Victron dealer could assist.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

christyler avatar image
christyler answered ·

If the gen start button worked as you say then the Cummins Onan setup withe the two relays discribed in the victron documentation will work for you.

It "converts" a contact closure switch, to a pulse for start and a pulse for stop.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

mocat avatar image
mocat answered ·

Hi all thanks for the input, I am amazed though with the amount of production boats sold with these Kohler generators on board and and after sale installations of Kohler gen sets besides Victron Quattros and multipluses with BMV 12 that there isn’t a easy to read and follow instruction sheet on what to me seems a necessity for successful operation.

Strange hey ....... has any body done this successfully out there at all with my model Kohler ?

4 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Mark avatar image Mark ♦♦ commented ·

Could you possibly run a quick test to start and stop your generator using 2x manual toggle or push button switches to confirm if the 'pulse' needs to be released before the generator starts or stops?

If it doesn't and it's not too sensitive to the exact 'pulse' length, then I think I can make it work using internal relays and a few 'assistants' in the Quattro.

Let me know if you get a chance to check/test and if your findings are promising I can advise further on this option.


Otherwise you need 2x DC time delay relays or timer circuits and a normal DC relay with NO & NC contacts.

EDIT: Since the BMV-712 relay has NO & NC contacts you don't need the additional normal relay, just the 2x time delay relays.

0 Likes 0 ·
cat-081801bmv-712-smart-back.png (3.6 MiB)
Show more comments
mocat avatar image
mocat answered ·

Hi thanks for that, but from what I read the GXbox does what my BMV 12 will do it’s the sucessfull interface Of the BMV to my Kohler gen set that’s my problem.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Victron BMV battery monitors product page

Additional resources still need to be added for this topic