question

Al avatar image

Can the SmartShunt get (STS) info from a Multi using DVCC?

Does the SmartShunt's SOC calculation need it's own independent temperature sense lead, or can it produce the same accurate SOC using the MultiPlus temperature lead with (STS) enabled?

I have Multi 24/3000/70, CCGX, 2 x MPPT 100/30, 530Ah PZS FLA batteries. Shorepwer, On a barge, with no other DC loads. (This is separate to navigation / starter battery system)

I currently use a Smartguage for accurate SOC and set the relay output to shutdown the Multi with assistants (only in case of a low SOC emergency). I'm about to install the two MPPT's, and have been adjusting the Multi's SOC parameters in VEConfig to mirror the Smartguage as closely as possible, but it's never that good.

If i get a SmartShunt I can use Ignore AC more accurately with its SOC, but if possible i'd like to use the midpoint monitoring function, rather than use another temperature probe on the SmartShunt, unless the SmartShunt's own temperature probe is needed for the most accurate SOC calcs?


Thanks Al

MultiPlus Quattro Inverter ChargerBMV Battery MonitorCCGX Color ControlDVCC
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Is there a definitive answer on whether the Smartshunt needs its own temperature probe, or if the CCGX calculates as good SOC using the Multi's probe with DVCC and (STS) enabled?

2 Answers
billknny avatar image
billknny answered ·

Al,

The smartshunt does not use temperature at all in its SOC calculation.

All the SmartShunt does is count power in and and subtract power out (with a few corrections factored in). and divide by the battery capacity you enter. The temperature doesn't enter into it.

I imagine it COULD, theoretically, adjust the entered capacity of the battery as a function of temperature, but as far as I know this is not done by any battery monitoring device.

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Thanks @billknny , I think I'm over thinking it, and you're right. My question should have been more focused on whether the (STS) setting will allow the Multi and CCGX to control charge and discharge sources I.E. the MPPT's at the max Amperage threshold adjusted for Temperature.. Which actually I'm sure it can.. So I don't need an extra Temperature probe for the SmartShunt, as the Multi's will tell the CCGX what Temperature the batteries are at, and like you say the shunt calculations shouldn't be affected by not knowing what temperature the batteries are as long as the Multi or CCGX gets it from somewhere.

@billknny

@Al

Re this quote..

"The smartshunt does not use temperature at all in its SOC calculation.

I imagine it COULD, theoretically, adjust the entered capacity of the battery as a function of temperature, but as far as I know this is not done by any battery monitoring device."

This isn't quite right. Maybe Victron is the first you've seen, now that you've seen it.. https://www.victronenergy.com/upload/documents/Manual-SmartShunt-EN.pdf See Section 7.3.2

It probably doesn't mean much for day-to-day usage, but seasonal conditions might make it important for some users


ejrossouw avatar image
ejrossouw answered ·

Hi @Al "Temperature (if optional temperature sensor connected)" From this I conclude the answer is no. It is in essence a data provider only and the bluetooth and VE.Direct are only used to transmit that data, not receive. Of course I stand to be corrected if something has changed much compared to the bmv-7xx

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Thanks, I thought maybe the 'optional' temp sensor is needed in a stand alone instance, but with a CCGX with DVCC enabled using shared temperature sense (STS) is the SOC algorithm then run in the CCGX? Which would allow me to still use the midpoint monitoring function and get the temperature from the Multi, but it's not clear in the CCGX / DVCCC or SmartShunt manuals?