I have a problem with the smartshunt and I would like to know if anyone has ever had the same problem.
The smartshunt after a few days, with the battery disconnected, shows an increasing SOC, and decreasing AH consumption. For example, a few days ago it showed a soc of 84% and 48 AH consumed, today I turn on the battery and it shows a soc of 86% and 41.7 AH consumed. As if there were a charging source that absolutely isn’t there. I would like to know if it is a setting problem and if there is a way to solve the problem because this is very unreliable
Not as uncommon as you think.
And is often settings or wiring related.
There is a whole post with resources. Your specific issue is mentioned in a link.
Thanks for the suggestion. I searched through the links but couldn’t find the possible solution to my problem. The battery soc increases day by day even if everything is turned off. I had removed 60AH from my 300Ah Lifepo4 battery and it read 79% now after 2 weeks I read 86% and 41 AH consumed…
Could you pls. post a screenshot of the live shunt data and a 24h trend with power and batt voltage ?
Where do you "switch off " ?
If the battery is disconnected your smartshunt shouldn’t communicate…
It is what i was wondering. If it is off and the battery is off and there is no charge source how is it powered?
Ok, I’ll try to give some more information:
- 1 lifepo4 battery 300AH
- 1 lead acid engine battery
- Negatives of the two batteries in common
- All the negatives of the boat (load and charge) are connected downstream of the shunt.
- Upstream of the shunt is connected with a single cable the negative lifepo4 service battery
- The voltage sensor cables of the batteries (engine and services) of the smartshunt are connected directly to the batteries
- I created a Ve.Smart network to which are connected shunt, DCDC charger, and battery charger.
- The service battery can be disconnected from the system using a battery switch
- Between the service battery and the engine battery there is DCDC OrionXS connected downstream of the service battery switch
- The battery charger (BlueChart IP 22) is connected downstream of the service battery switch
- The engine battery has its own battery switch that disconnects all the positives (alternator, starter motor, DCDC Charger)
- There is no battery charger for the engine battery
Now, with the charger disconnected from the 220V and the service and engine battery disconnector open, after some time I detect a higher SOC in percentage and a lower amount of AH consumed
For example this morning I was on the boat and the battery showed 86% SOC and 41.7 AH consumed.
I disconnected all the batteries and went away
This evening at 18.06 it showed a SOC of 87% and 40.8 AH consumed (0.9 less).
Initially I thought it was the engine battery charging the service battery but the voltage of this has been fixed for at least 2 weeks, and then I don’t know how it could happen.
HELP please, tell me that there is a wrong setting somewhere because this way it is totally unreliable
Attached are the two screenshots from 12.23 and 18.06 and the screenshot of the shunt settings
A diagram, even hand drawn and photographed is helpful.
- A common problem with shunts on boats is the connection of the 2. battery negative to the hull ground. If there is a connection from battery negative to hull ground this must be from the starter battery or from the load side of the shunt. The service battery must not be connected to hull ground.
- A second common error is the common connection between the engine and service batteries. This must connect from the engine battery negative to the load side of the shunt.
- The negative of the DC to DC charger must go to the engine battery or the load side of the shunt.
- You are measuring a charge current. You need to see if this is real or an error. Disconnect everything from the load side of the shunt so there can be no current flowing through it. Does it now read zero, if it does the shunt is OK and you have a wiring or equipment issue to understand. If the shunt reads a current with nothing connected to the load side then it has a zero error and needs calibrating. See the manual Section 7.2.13. The button is at the bottom of the settings screen.
The charged voltage in the smart shunt is too low, should be ~14.2volts, tail current 0.5%.
Pls post same pix with isolator in off position
all my negative cables and the ground of the motor and the various metal parts are connected together downstream of the shunt, as in the diagram you sent.
For greater clarity I am sending you a diagram of my system, consider that there is a complication for an old shunt connected to the positives that I already had in the panel. It is however a very useful counter-proof of what I read from the smartshunt
As you can see the negatives are all downstream of the shunt.
Tomorrow I will do the test you recommended and I will disconnect everything from the load side on the shunt and check the current
In the meantime, thanks
Circuito GS39-1.pdf (352,9 KB)
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I don’t think the charging current and the tail current have any influence on my problem.
Tomorrow I’ll send the screenshots you asked for
Thanks in the meantime
You’re right, but in the long run you’ll need to correct those values.
With the service battery disconnected, a positive current (charging) of 0.17 AH is actually shown. At this point I did as recommended in the manual, I disconnected the negative from the load side of the shunt and calibrated the zero with the batteries off. However, there is a problem: even if the battery switch is open, the shunt remains on and is powered by the voltage sensors of the two batteries (services and engine) because the two small cables go directly into the two batteries, bypassing the battery switch. In this way the shunt marks zero current but there is a micro current at the output to keep the shunt turned on. Is this normal?
OK, you have now solved your problem, good news.
The current for the shunt is <1mA so it will use 1Ah of battery capacity in more than 40 days so this is not an issue. The shunt only measures 0.1A current and above anyway, so the consumption is very small.
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I solved my problem thanks to your advice.
Thanks