Installing a Magnum Energy BMK to a 2017 DSDP

[harbortime]

Magnum recommends you remove the positive cable before you remove the negative. They also say you need to connect the positive cable last.

This is the first time I have heard a company recommend the opposite of what everyone else teaches.

They say this in the BMK instructions.

[C.Martin]

Originally Posted by harbortime

Magnum recommends you remove the positive cable before you remove the negative. They also say you need to connect the positive cable last.

This is the first time I have heard a company recommend the opposite of what everyone else teaches.

They say this in the BMK instructions.

It's good you posted this here...very relevant.

It is easy to skip over in the BMK instructions...but it's there.

At least it's a big CAUTION in the Inverter Manual... too bad they didn't make it a CAUTION in the BMK manual. The CAUTION goes onto say if the Inverter still has POS connected when the NEG is removed it may try to find another path to ground and damage the communication chips in the all of the NETWORK accessories.

When I replaced my 3/0 neg cable with a 4/0 cable...my BMK started reading off the chart. It still communicated with the ME-ARC...but it would read the wrong direction of current flow and the wrong amperage. It stayed in a steady state of "Think'n". ...replaced it with another BMK module...and it's back to working.

Lesson learned.

Everyone should be made aware of this...if they take their coach in for something related to the system and the technician isn't aware...it may fry some of the accessories.

[Scottybdivin]

That's pretty bizarre and counter intuitive. I must have missed that warning because I installed my BMK and disconnected / re-connected the ground first. I will definitely look into it. It has also been recommended by some Newmar folks on here to pull the fuses for the intellitec slide controllers before disconnecting and possibility of arcing. I have done so just in case.

[Golfer Guy]

Wow, what a great thread. I am in the process of adding the BMK to my system and this info is just what I need. thanks to everyone who has contributed, Charlie especially. Great info. This gives me hope that I can make this a DIY project even though I am electrically challenged.

I want to make sure that what I do does not conflict with the AGS and solar that is on my coach. Just added 600 watts solar 6 Trojan T145 Batteries and want to know what my SOC is.

Will be following this tread closely.

Steve

[C.Martin]

Originally Posted by Golfer Guy

Wow, what a great thread. I am in the process of adding the BMK to my system and this info is just what I need. thanks to everyone who has contributed, Charlie especially. Great info. This gives me hope that I can make this a DIY project even though I am electrically challenged.

I want to make sure that what I do does not conflict with the AGS and solar that is on my coach. Just added 600 watts solar 6 Trojan T145 Batteries and want to know what my SOC is.

Will be following this tread closely.

Steve

It's not me...it's just a great community working together to solve problems and give our rolling escapes some TLC.

[Jrhea]

I am installing a magnum BMK as well and have a similar wiring setup as posted earlier in this thread, but my house ground is connected to the same place as the words "chassis ground" in this picture. I then just have the one chassis ground connecting to the load side of my BMK, along with my inverter ground.

Am I missing out on anything if I do it this way instead of relocating all the grounds that are attached to the chassis ground mounting point?

John

[Scottybdivin]

Magnum says all of the grounds need to feed through the shunt as in the picture.

[Kiawah]

Originally Posted by Jrhea

I am installing a magnum BMK as well and have a similar wiring setup as posted earlier in this thread, but my house ground is connected to the same place as the words "chassis ground" in this picture. I then just have the one chassis ground connecting to the load side of my BMK, along with my inverter ground.

Am I missing out on anything if I do it this way instead of relocating all the grounds that are attached to the chassis ground mounting point?

John

That's fine.

The important thing is that the ONLY thing that gets connected to the negative battery post, is one side of the BMK. Everything else, needs to go to the other side of the BMK shunt. That way ALL current will be going thru the shunt.

This paragraph deals with your chassis ground cable question. Remember that you have different types of power consumption on your coach. The inverter/converter for instance, will have it's current coming back on the inverter cable. A 12v tail light for instance, has it's negative connected to the frame of the coach, and it uses the frame as it's path back to the battery. That current would be coming back to the battery via the chassis ground cable that you point out. So it comes thru the chassis, to the chassis ground cable, thru the shunt, and then to the battery. Whether electrical current comes back via it's own electrical cable, or back thru the chassis frame, doesn't really matter as long as all of the current goes thru the shunt on the way to the battery.

I have my setup looking slightly different as well (but electrically it works identical with all negative current going thru the shunt):
- The negative battery cable goes to one side of the shunt
- The other side of the shunt has a short cable that is connected to a short buss bar, which has a couple bolts on it.
- One bolt has a short cable that is connected to the chassis.
- Another bolt has a negative cable connected to the inverter
- Other bolts have smaller wires/cables going to other devices.

[Jrhea]

Originally Posted by Kiawah

That's fine.

The important thing is that the ONLY thing that gets connected to the negative battery post, is one side of the BMK. Everything else, needs to go to the other side of the BMK shunt. That way ALL current will be going thru the shunt.

This paragraph deals with your chassis ground cable question. Remember that you have different types of power consumption on your coach. The inverter/converter for instance, will have it's current coming back on the inverter cable. A 12v tail light for instance, has it's negative connected to the frame of the coach, and it uses the frame as it's path back to the battery. That current would be coming back to the battery via the chassis ground cable that you point out. So it comes thru the chassis, to the chassis ground cable, thru the shunt, and then to the battery. Whether electrical current comes back via it's own electrical cable, or back thru the chassis frame, doesn't really matter as long as all of the current goes thru the shunt on the way to the battery.

I have my setup looking slightly different as well (but electrically it works identical with all negative current going thru the shunt):
- The negative battery cable goes to one side of the shunt
- The other side of the shunt has a short cable that is connected to a short buss bar, which has a couple bolts on it.
- One bolt has a short cable that is connected to the chassis.
- Another bolt has a negative cable connected to the inverter
- Other bolts have smaller wires/cables going to other devices.

Thank you! This is exactly the information I was looking for. I appreciate the help!

John

[DrPhil]

Originally Posted by Kiawah

That's fine.

The important thing is that the ONLY thing that gets connected to the negative battery post, is one side of the BMK. Everything else, needs to go to the other side of the BMK shunt. That way ALL current will be going thru the shunt.

This paragraph deals with your chassis ground cable question. Remember that you have different types of power consumption on your coach. The inverter/converter for instance, will have it's current coming back on the inverter cable. A 12v tail light for instance, has it's negative connected to the frame of the coach, and it uses the frame as it's path back to the battery. That current would be coming back to the battery via the chassis ground cable that you point out. So it comes thru the chassis, to the chassis ground cable, thru the shunt, and then to the battery. Whether electrical current comes back via it's own electrical cable, or back thru the chassis frame, doesn't really matter as long as all of the current goes thru the shunt on the way to the battery.

I have my setup looking slightly different as well (but electrically it works identical with all negative current going thru the shunt):
- The negative battery cable goes to one side of the shunt
- The other side of the shunt has a short cable that is connected to a short buss bar, which has a couple bolts on it.
- One bolt has a short cable that is connected to the chassis.
- Another bolt has a negative cable connected to the inverter
- Other bolts have smaller wires/cables going to other devices.

Maybe you have a picture?

[Scottybdivin]

I did my setup the same way, I used a busbar to connect all of the negative cables then one single cable on both sides of the shunt. Hope this helps.

[Mike Bartelt]

My setup is different as well, but I have all the negatives running to the bus, the other end of the shunt is the only thing that is supposed to connect to the negative of your bank.

If you have the ARC and add the PT-100 you can either link charging/battery settings with the inverter or keep them separate. I have the PT-100 set for a slightly more aggressive charge, but within manufacturer settings.

I added the SBC- Smart Battery Combiner because I'm almost never plugged in and it helps keep my chassis batteries topped off, and it seems to add a bit more current to the house batteries when I'm on the road.

[FlaRider]

Originally Posted by C.Martin

I just used brass... maybe not as strong, but I believe that is what the shunt is made of...

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Charlie,

When you swapped out the Magnum Shunt to the Victron BMV712 did that 1" bolt you bought from Amazon still work? I went to Ace to see if they had a longer bolt and it seems that the Victron shunt uses a metric bolt (M10x1.5M).

One of the first time Ace was not the place.

Marc

[NealC]

We did use the longer bolt as it works but it’s not perfect as you found out Victron is metric. But the CharlieBolt worked fine. If you can find a metric alternative that would be ideal.