Lion Lithium Batteries / Added SmartShunt installation

Sharon_is_SAM

@Denny16 - I have never seen an explanation or diagram indicating that the solar charge controller negative lead can be connected directly to the battery.  I purchased our shunted Victron battery monitor from PYS and here is what I found on their website:

In addition, we initially connected the controller directly to the battery and the battery monitor did not reflect solar charging as it occurred, rather the monitor values would “jump”.  It wasn’t until we connected the controller after the shunt that we saw the battery monitor reflect real time charging.  

JT4

I have been watching the comments a bit.  I have my Solar MPPT wired so that it always feeds the battery directly.  It bypasses the battery disconnect to the the T@B itself and can charge the battery directly.

kbdigitiqe

JT4 said:

I have been watching the comments a bit.  I have my Solar MPPT wired so that it always feeds the battery directly.  It bypasses the battery disconnect to the the T@B itself and can charge the battery directly.

I think this is helpful so that you can still charge with the battery disconnect in the off position, but @Sharon_is_SAM is saying is that then you cannot actually "see" the solar charging the battery in the battery monitor, which is what I wish I could see, only because then the "time remaining" value would hopefully take into account the incoming charge? curious Sharon if you know if that's true?

Denny16

Sharon, you are right, I got this backwards (senior moment, haha), corrected my previous posts.  Thanks.

Sharon_is_SAM

@kbdigitiqe - the BMV shunted battery monitor considers multiple variables to determine state of charge and time remaining.  But the volts delivered to charge the battery (and the current flow measured in amps) are certainly accounted for in the BMV display.  When we used solar on our Utah trip, we had both solar controller leads going directly to the battery.  It was confusing because we knew we we’re charging (saw + amps on the monitor), but the state of charge would not change.  Then all of a sudden like magic we would be back to 100%.  So, I think with the controller tied in after the shunt, there will be a viewable, gradual increase in voltage and state of charge.  Hope that helps.

kbdigitiqe

Thanks @Sharon_is_SAM - so I re-wired and pulled the negative from the solar off the battery and installed it to the load side of the shunt now, but I'm curious if this info on the BMV looks right? It's showing a 45w draw and nothing is on inside the camper at all and it shows my time remaining as "Infinite" which I guess makes sense since the solar is performing really well in the sun right now. Seems fishy though and I'm wondering if I've wired something wrong??

EDIT: FIGURED IT OUT! Duh... I looked back at older screen grabs and normally the batter shows a negative number when power is begin consumed.. lol - the reason it shows 46W here is because that is what the solar is delivering it - a net positive of 46W 

Denny16

Do you also have the Victron MPPT Solar Controller?  If so, you can network the two together via Bluetooth, and then the two devices will share info. more accurately.  

Cheers 

kbdigitiqe

@Denny16 yes and they are already networked together

Denny16

Good, he Battery Monitor will show the current state of the battery, and any loads on it, as shown in your example.  The Solar charge being received is displayed on the MPPT phone App.  The Battery monitor uses the charge current/voltage info from the MPPT to calculate your Time Remaining status, which shows Inf. when power from the solar panels exceeds the current draw on the battery, which is what your posted display shows.  The monitor also shows State of Charge of the Battery, which is shown as 100% in your example, along with 13.47 VDC (typical fully charged battery voltage).  

So yes, the display you posted looks correct.  Did you set the Battery Monitor and Solar Controller setup for the Battery you are using?  If so, than you are all set. 
cheers

kbdigitiqe

Thanks @Denny16 edited my previous post just now - and your explanation is far better than my own .. lol

Denny16

You are welcome @kbdigitiqe, this is my understanding on how the two units work together.  If you add the Temp probe accessory hookup to the Battery Monitor, it will share the actual battery temp with the a MPPT solar controller to adjust charge rate based on battery temp. I added this to our setup.
cheers

JT4

Thanks for the interesting info Denny. I will certainly study your described setup some more.  

m_lewis

While your photos look correct, the language has a mistake. All negative wires must go to the load side of the shunt, with the other side connected to the battery. Do not wire anything directly to the battery’s negative terminal except the shunt. 

To bypass the shunt with the MPPT negative would disable the metering of solar charging current, yielding false state of charge data, the main reason for having the SmartShunt in the first place. 

Edit: I missed the last few msgs showing the wiring corrections. What you saw re state of charge was what it should do whenever it detects a “full” voltage, resetting to 100%. 

Denny16

Thanks @m_lewis, you are correct, I  fixed my post, missed the one inaccurate bit.
cheers

m_lewis

Yes, whoever wrote quantum physics might be easier to understand than DC circuits, solar power and battery monitoring, might be right. I’ve studied both, the latter at length, so I disagree. 

It’s like a magicians trick; easy once you know how. 

TNOutback

If you purchased the BMV with the temperature sensor, it can pass battery temperature to the solar charge controller as well.

Marceline

m_lewis said:

While your photos look correct, the language has a mistake. All negative wires must go to the load side of the shunt, with the other side connected to the battery. Do not wire anything directly to the battery’s negative terminal except the shunt. 

To bypass the shunt with the MPPT negative would disable the metering of solar charging current, yielding false state of charge data, the main reason for having the SmartShunt in the first place. 

Edit: I missed the last few msgs showing the wiring corrections. What you saw re state of charge was what it should do whenever it detects a “full” voltage, resetting to 100%. 

@m_lewis
 I just want to be sure that I have this correct.
I have Victron SmartShunt. I have an old solar suitcase with a built in controller. I recently wired up an SAE port to my battery, and I have it connected directly to the battery positive and negative terminals. Can you confirm that the negative line from the SAE port should be connected to the SmartShunt negative post?

Thanks. 

Denny16

yes, yes it should, just like the factory solar.  The suitcase sold panels have the controller, so the output of those panels is from the controller.  The only thing connected directly to the battery negative post, is the Smart Shunt.
cheers