Jump to content

DC shunt size


GlennWest

Recommended Posts

OK, according to that I will need a seperate buss bar on the negative side.Seperate the batteries from the loads. Connect the shunt between the two. Correct?

Edited by GlennWest

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

  • Replies 56
  • Created
  • Last Reply

Top Posters In This Topic

19 hours ago, Sehc said:

The only way a shunt based monitor works is if all the negatives return through it. I have 3 x 12 volt battery banks. Each negative goes to the shunt. The shunt then goes to a bus bar. The bus bar has a connection to the chassis and the negative from all other devices. All the power from the whole battery bank returns through the shunt to the bank negative.

Here is a link to how the Balmar SG200 monitor works. https://marinehowto.com/balmar-sg200-self-learning-battery-monitor/

You state each negative from battery pack to shunt. Did you put 3 grounds on 1 shunt post?

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

Assuming  you have three #8 negative wires, one from each battery pack, these would go on one terminal of the shunt. Negative leads from the Inverters etc., would go on the other terminal of the shunt. 

Foretravel 40ft tag 500hp Cummins ISM  1455 watts on the roof, 600 a/h's lithium in the basement.

 

Link to comment
Share on other sites

Yes, I was going to comment on this also Glenn. Did I understand right you have three packs? If you have three separate packs then you need to monitor each pack. I think you could do a shunt on negative each pack and then a shunt on the main negative for a total reading. This is where it could  make a huge difference what brand monitor you go with as some can communicate with each other and some not.

Dave and Lana Hasper

Link to comment
Share on other sites

My negative leads off batteries are #4, So you are saying it is a good practice of all these 3 cables on 1 shunt post? That would save room vs a second bussbar.

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

4 minutes ago, Daveh said:

Yes, I was going to comment on this also Glenn. Did I understand right you have three packs? If you have three separate packs then you need to monitor each pack. I think you could do a shunt on negative each pack and then a shunt on the main negative for a total reading. This is where it could  make a huge difference what brand monitor you go with as some can communicate with each other and some not.

That is correct. I didn't tie my battery packs together. I have 3 positive and 3 negative leads. I don't know if Magnum supports this or not. You are specing 4 shunts.Looks like I would need 4 bmks and maybe multiple monitors. My BMS will protect my individual cell paks. This would be nice but is it necessary? You all are a lot more exsperienced than me. I have three BMS units. One on each pack. They are wired to each module. 

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

8 minutes ago, Daveh said:

Depending on your setup there may be a place for something like this in your system. https://www.magnum-dimensions.com/smart-battery-combiner.   My concern is that your packs will get out of balance.

 

Doesn't look like that is an option for 48 volt packs. https://forum.solar-electric.com/discussion/353276/battery-combiner-for-2-mixed-48v-banks    I would just want to know exactly what was going on in each pack. You could rely on the BMS but won't your low voltage cutoff be lower than what you normally would want to run your batteries down too. That is where the victron and magnum shunt monitors are nice because they will alarm the pack at a voltage above your low voltage cutoff based on amps used.   

 

 

Dave and Lana Hasper

Link to comment
Share on other sites

22 minutes ago, Daveh said:

So you will have three 48 volt packs each with a separate charging source?

 

 

 

I have 3 48v (actually 58v) packs. they go to a bussbar and my Magnum inverers and future solar connect to that bussbar to provide charging. My sytem will run independent of shore power. Run strickly off batteries. Shore power will hook up at inverter 110 connection to supply charging only. 

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

Getting confusing. I have the same setup as Glen. I treat each 48 volt battery pack with BMS as a single battery, and just parallel them. [with breaker/disconnect on each battery positive] So, 3 negatives connected to one side of shunt, and other side of shunt connected to negative post of inverter. 3 positives are on positive post of inverter.

Foretravel 40ft tag 500hp Cummins ISM  1455 watts on the roof, 600 a/h's lithium in the basement.

 

Link to comment
Share on other sites

Yes the terminology is getting confusing. I would call your set up 1 pack made up of three packs in parallel.  If the three packs are connected they should be in voltage balance. You probably still want to separately monitor the voltage on each 48 volt "component" battery but I would think you could do that rather inexpensively without the need for a separate shunt etc. Just use one shunt.

Dave and Lana Hasper

Link to comment
Share on other sites

5 minutes ago, Daveh said:

Yes the terminology is getting confusing. I would call your set up 1 pack made up of three packs in parallel.  If the three packs are connected they should be in voltage balance. You probably still want to separately monitor the voltage on each 48 volt "component" battery but I would think you could do that rather inexpensively without the need for a separate shunt etc. Just use one shunt.

As he bought the same packs that I have, believe he has the bms with bluetooth, and can monitor cell voltages and currents on his phone with the proper app.

Foretravel 40ft tag 500hp Cummins ISM  1455 watts on the roof, 600 a/h's lithium in the basement.

 

Link to comment
Share on other sites

16 minutes ago, jcussen said:

As he bought the same packs that I have, believe he has the bms with bluetooth, and can monitor cell voltages and currents on his phone with the proper app.

No blue tooth. Nothing that fancy. My 3 battery pack are Parelled to bussbars. So  Magnum bmk sees it as one battery. With the BMS i see no need to monitor each pak. 

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

30 minutes ago, jcussen said:

As he bought the same packs that I have, believe he has the bms with bluetooth, and can monitor cell voltages and currents on his phone with the proper app.

I had mentioned using the REC bms which interphases with Victron equipment a while back. That is likely why you thought that. The indiuvidual I got my batteries from discouraged me form setting this up myself and he is likely right. He set up this system and it is a KISS. I don't have to be concerned about it. If I had a lot of time on my hands, maybe that would be better but I don't. Later, yes, but not now.

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

I have Ralph's basic BMS made by Xiaoxiang.  Bluetooth is standard. Might ask him, and he can send you a link for the app, if you have the same BMS.  But, as you say,  not absolutely necessary. Don't think you can get three  4 gauge lugs on the shunt, so you might have to get a seperate busbar or make a copper bar.

Edited by jcussen

Foretravel 40ft tag 500hp Cummins ISM  1455 watts on the roof, 600 a/h's lithium in the basement.

 

Link to comment
Share on other sites

Ok. I will ask. Mine is a ROHS 14s48v 100 amp. Also got DAIY on it. These numbers 1-101-12340-24A. It looks just like one you posted though. Been researching and nothing mentioned about bluetooth ability. Contacted Ralph. Said you had the open style bms with bluetooth, 60 amp. Mine are sealed and 100 amp plus. 

Edited by GlennWest

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

4 hours ago, jcussen said:

I have Ralph's basic BMS made by Xiaoxiang.  Bluetooth is standard. Might ask him, and he can send you a link for the app, if you have the same BMS.  But, as you say,  not absolutely necessary. Don't think you can get three  4 gauge lugs on the shunt, so you might have to get a seperate busbar or make a copper bar.

The one magnum sends with their bmk has bolts instead of studs. I could just get a longer bolt. I am thinking of space saving vs adding another bussbar.

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

3 minutes ago, GlennWest said:

The one magnum sends with their bmk has bolts instead of studs. I could just get a longer bolt. I am thinking of space saving vs adding another bussbar.

Good idea. Might do the same.

Foretravel 40ft tag 500hp Cummins ISM  1455 watts on the roof, 600 a/h's lithium in the basement.

 

Link to comment
Share on other sites

On 12/24/2019 at 10:11 AM, GlennWest said:

What I don't like about Victron is their larger size also no 230v units. 

I was referring to the battery monitor. There are some differences with the inverter technology that may not be optimal for all users. But for most they work well.

Jack & Danielle Mayer #60376 Lifetime Member
Living on the road since 2000

PLEASE no PM's. Email me. jackdanmayer AT gmail
2016 DRV Houston 44' 5er (we still have it)
2022 New Horizons 43' 5er
2016 Itasca 27N 28' motorhome 
2019 Volvo 860, D13 455/1850, 236" wb, I-Shift, battery-based APU
No truck at the moment - we use one of our demo units
2016 smart Passion, piggyback on the truck
-------------------------------------------------------------------------
See our website for info on New Horizons 5th wheels, HDTs as tow vehicles, communications on the road, and use of solar power
www.jackdanmayer.com
Principal in RVH Lifestyles. RVH-Lifestyles.com

Link to comment
Share on other sites

21 hours ago, GlennWest said:

The one magnum sends with their bmk has bolts instead of studs. I could just get a longer bolt. I am thinking of space saving vs adding another bussbar.

What I often do Glenn, is put a piece of copper bar drilled out for your extra loads - custom drill for what you need.. This connects at the shunt and gives you a place to mount additional wires. It is a neat solution that does not take up much space, just hung off the shunt. It does depend on your needs, though. If only a few wires then stacking them works. I use 1/4"x1" stock for 400A loads.

Jack & Danielle Mayer #60376 Lifetime Member
Living on the road since 2000

PLEASE no PM's. Email me. jackdanmayer AT gmail
2016 DRV Houston 44' 5er (we still have it)
2022 New Horizons 43' 5er
2016 Itasca 27N 28' motorhome 
2019 Volvo 860, D13 455/1850, 236" wb, I-Shift, battery-based APU
No truck at the moment - we use one of our demo units
2016 smart Passion, piggyback on the truck
-------------------------------------------------------------------------
See our website for info on New Horizons 5th wheels, HDTs as tow vehicles, communications on the road, and use of solar power
www.jackdanmayer.com
Principal in RVH Lifestyles. RVH-Lifestyles.com

Link to comment
Share on other sites

On ‎12‎/‎25‎/‎2019 at 10:11 AM, GlennWest said:

next question, should I go thru trouble of making a copper bar to attach to my shunt or just put all three cables on post?

Glenn, if you only have three cables to attach,,,,,,, and if all three will fit correctly on one shunt post without crowding,,,,,, I would do that versus messing with an extra bar and connection and taking up extra space.

John T

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

RVers Online University

mywaggle.com

campgroundviews.com

RV Destinations

Find out more or sign up for Escapees RV'ers Bootcamp.

Advertise your product or service here.

The Rvers- Now Streaming

RVTravel.com Logo



×
×
  • Create New...