Balmar SG-200 Battery Monitor

[ayates]

Originally Posted by lateral

Studs ok, but I didn't get the grey cover for the spare port.

The grey cover I sourced myself. It is a standard Deutsch part (DT4P-DC):


https://www.mouser.ca/ProductDetail/...rrencycode=CAD




Allan.

[River Cruiser]

I bought one of these and haven’t seen it yet. Had a friend who works for WM near St. Louis order it and because of flooding on the river haven’t been to the marina. I have on/off switches on all my batteries. I would imagine the shunt should be wired in before the switch can anyone verify this is correct?

[witzgall]

RC,

The Smartshunt main cable connections are made on the negative side, not the positive. Generally, here is how you do it:

Disconnect the negative-most cable from the battery or battery bank. This would be the one running off to the loads and sources. Place that on the stud marked "Cable" on the smartshunt.

Then, run a new cable from the stud marked "Batt" back to the battery. This should be the only negative cable on the battery. If there are others, move them to the "Cable" side of the shunt. Install a bus bar there if needed (You don't want lots of cables connected directly to the the Smartshunt. It is better to use a bus bar for multiple connections, with one cable from that going to the Smartshunt).

With the fuse out of the red wire (it should be already out and in a bag) connect the red wire to the positive-most post on the battery.

That is it for the power connections to the smartshunt, except if you use the aux voltage leads. If you do, make sure you put a fuse at the battery end of each of those leads (Not included).

The manual has been updated on our website, you should download and use this one: http://www.balmar.net/wp-content/upl.../PDS-SG200.pdf

Chris

Originally Posted by River Cruiser

I bought one of these and haven’t seen it yet. Had a friend who works for WM near St. Louis order it and because of flooding on the river haven’t been to the marina. I have on/off switches on all my batteries. I would imagine the shunt should be wired in before the switch can anyone verify this is correct?

[lateral]

Originally Posted by witzgall

RC,

The Smartshunt main cable connections are made on the negative side, not the positive. Generally, here is how you do it:

Disconnect the negative-most cable from the battery or battery bank. This would be the one running off to the loads and sources. Place that on the stud marked "Cable" on the smartshunt.

Then, run a new cable from the stud marked "Batt" back to the battery. This should be the only negative cable on the battery. If there are others, move them to the "Cable" side of the shunt. Install a bus bar there if needed (You don't want lots of cables connected directly to the the Smartshunt. It is better to use a bus bar for multiple connections, with one cable from that going to the Smartshunt).

With the fuse out of the red wire (it should be already out and in a bag) connect the red wire to the positive-most post on the battery.

That is it for the power connections to the smartshunt, except if you use the aux voltage leads. If you do, make sure you put a fuse at the battery end of each of those leads (Not included).

The manual has been updated on our website, you should download and use this one: http://www.balmar.net/wp-content/upl.../PDS-SG200.pdf

Chris

I didn't see any reference to <350A and multiple shunts in the new manual?

[River Cruiser]

Chris thank you for the information

[witzgall]

I think you are referring to paralleling two shunts so that 350a can be exceeded continuously. A single shunt can handle 350a continuously, and 600a for 10 minutes. That 600a figure may be higher, we did not have a system in place to hold that current for over 10 minutes! Although the limiting factor is the temperature of electronic components, for safety let's stay with the rated specs.

We have a method figured out to allow the paralleling of two shunts to increase those capacities to 700a and 1200a respectively. NOTE parallel, not series!!! This will require the feature to be implemented in software, which it is not currently. When available, it will enabled by using the phone app, which means you will need the BT gateway. Essentially the software will make two shunts appear as one. This is outlined in the manual on page 13. I don't think the feature will make it into the first firmware update, but I expect it to follow in one of the updates directly after the first.

Chris

Originally Posted by lateral

I didn't see any reference to <350A and multiple shunts in the new manual?

[witzgall]

As always, customer feedback is important to Balmar, and has been for 35+ years. I wanted to take the time to address the screen issue that has come up on the forum in the last few days.

An issue recently appeared on a portion of the color displays. When the unit is uninstalled and off, a small, dark spot or spots appear on the display. The design calls for a very thin air gap between the LCD display and the front protective lens. The gap must be very thin to reduce the possibility of fogging. On the affected units, the front lens touches the LCD, and this appears as a spot.

We have thoroughly analyzed the issue and found it to be purely cosmetic. When the display is powered on, the spot is nearly impossible to see. The issue does not impact the functionality or lifespan of the product.

A fix for this cosmetic problem is already being implemented, but it will take a few months for new displays to make their way into the marketplace. While most users have not found the issue to be objectionable in actual use, we will entertain replacing the affected units when new material is available, based upon customer request. However, this will require a return of the display to us for a swap out.

Chris

[lateral]

Originally Posted by witzgall

I think you are referring to paralleling two shunts so that 350a can be exceeded continuously. A single shunt can handle 350a continuously, and 600a for 10 minutes. That 600a figure may be higher, we did not have a system in place to hold that current for over 10 minutes! Although the limiting factor is the temperature of electronic components, for safety let's stay with the rated specs.

We have a method figured out to allow the paralleling of two shunts to increase those capacities to 700a and 1200a respectively. NOTE parallel, not series!!! This will require the feature to be implemented in software, which it is not currently. When available, it will enabled by using the phone app, which means you will need the BT gateway. Essentially the software will make two shunts appear as one. This is outlined in the manual on page 13. I don't think the feature will make it into the first firmware update, but I expect it to follow in one of the updates directly after the first.

Chris

Actually no, I don't envisage load/charge > 350A anytime in the future so I am not referring to that. Not even close to 350A.
If you read my question it has a "less than 350A " scenario.

I am referring to shunts that already exist to the negative bus.
That they must be in series with the smartshunt or will render both inaccurate if paralleled.

Furthermore, I did hesitate before my purchase owing to the cavalier attitude some have encounter with your company on
encountering problems. Now have experienced first hand with
the blemish issue. MS's review is what sold me.
I reckon your PR machine needs tuning.
M2CW

[witzgall]

Ah,Sorry. In that case, we are fine with another (Non Smartshunt) being in the negative path to the battery, as long as the Smartshunt is the one closer to the battery. In other words, there should not be another shunt in between the Smartshunt and the battery.

Chris

Originally Posted by lateral

Actually no, I don't envisage load/charge > 350A anytime in the future so I am not referring to that. Not even close.
I am referring to shunts that already exist to the negative bus.
That they must be in series with the smartshunt or will render both inaccurate if paralleled.

[AndyEss]

A DC shunt ammeter works by measuring the voltage drop across the shunt i.e. it measures voltage. Using Ohms Law and the known, calibrated resistance of the shunt itself, allow the meter to be set to read the current (Amps) flowing across the shunt.
If the meter includes a clock and microprocessor, getting Amp-hours used (or generated) from the meter readout is possible.
When placing your shunts (if you have multiple shunts) remember that these are voltage drop devices. They don't directly measure current flow. For example, if you have multiple meters, you would wire each shunt in series. If on the other hand, you want to measure current flows greater than the safe capacity of one shunt (remember, these are voltage drop devices, so heat is generated by the current flow through the resistive element) and you are feeding one ammeter, you would wire the two (or multiple) shunts in parallel. The meter itself would need to know how many shunts were wired in parallel to provide the correct Amp (and/or Amp-hr) reading.
Keep in mind that the miniscule voltage drop across each shunt (if you have multiple shunts in series) will effect the voltage available in your entire system.
Heisenberg was right.

[Cat36Mahalo]

I just got back from a 3 week cruise in the San Juan and Gulf Islands. I really liked having the SG200 on and running. I could tell at a glance if I needed to break out the Honda generator or wait another day. Also when the generator was running I knew how long to explore the coves and shoreline, to come back to a fully charged boat and shutdown the generator. Hours at current consumption is more important to me than amp hours used.

I do have a blue sea 422 coulomb counter, but this is much nicer. Since it does have current and hours left at this current - you could use that to figure out how many Ah left to half full, but why??

[lateral]

Originally Posted by AndyEss

A DC shunt ammeter works by measuring the voltage drop across the shunt i.e. it measures voltage. Using Ohms Law and the known, calibrated resistance of the shunt itself, allow the meter to be set to read the current (Amps) flowing across the shunt.
If the meter includes a clock and microprocessor, getting Amp-hours used (or generated) from the meter readout is possible.
When placing your shunts (if you have multiple shunts) remember that these are voltage drop devices. They don't directly measure current flow. For example, if you have multiple meters, you would wire each shunt in series. If on the other hand, you want to measure current flows greater than the safe capacity of one shunt (remember, these are voltage drop devices, so heat is generated by the current flow through the resistive element) and you are feeding one ammeter, you would wire the two (or multiple) shunts in parallel. The meter itself would need to know how many shunts were wired in parallel to provide the correct Amp (and/or Amp-hr) reading.
Keep in mind that the miniscule voltage drop across each shunt (if you have multiple shunts in series) will effect the voltage available in your entire system.
Heisenberg was right.

In your opinion, would having the smartshunt closer to the battery negative have any relevance? My rationale is, no.
It means a re-jig for me & possibly putting the Smartshunt in a vulnerable position.
The electrons flow from -ve to +ve and current the opposite.
Both shunts exhibit volt drops, which will be first; does it matter.?
Balmar must have tested this to state it, albeit via a forum.

[AndyEss]

I don't think the placement of two series shunts relative to each other would make any difference at all - voltage drop is voltage drop.
I suspect the recommendation of putting the Balmar closest to the battery negative post just has to do with trying to establish some consistency in suggested best practices. They are selling to a reasonably large market.
I like "rolling my own" instrumentation and can't see that should make any difference- but am willing to listen to what Balmer may have to say.
Putting their shunt closest to the battery negative may make some improvement to accuracy if additional negative grounds from future circuits get attached to "convenient" shunt cable studs.

[lateral]

It is also mentioned that SS should be placed as close to battery as possible. In my case this is not convenient. I want to place it in the engine bay next to negative bus bar.
No mention of heat/vibration tolerance, only moisture and curved surfaces??
At a $130 apiece, not trivial.
I guess i'm gonna be that PIA customer.

FWIW, I will get back with my experience once it is up and running
viewed from PIA customer perspective.

[AndyEss]

Originally Posted by lateral

It is also mentioned that SS should be placed as close to battery as possible. In my case this is not convenient. I want to place it in the engine bay next to negative bus bar.
No mention of heat/vibration tolerance, only moisture and curved surfaces??
At a $130 apiece, not trivial.
I guess i'm gonna be that PIA customer.

Again, I can't see that being close or far from the battery would make any difference whatsoever to the voltage drop across the shunt itself.
Since resistance of most metals is temperature dependent, varying temperature of a shunt would have some effect on meter accuracy. I've never heard of a temperature compensated shunt. The ones I get direct from electronics vendors certainly aren't temperature compensated.
(FYI I used to work with high end strain gage loadcell data acquisition systems.) All these aspects were highly important to accurate results. Battery hysteresis makes some of these fine points totally immaterial to monitoring battery SOC. I needed results accurate to nearly parts per million levels with the strain gage systems. Battery SOC is probably good enough at +/- 5% levels.