question

birdie avatar image
birdie asked

SmartShunt resets consumed ah / state of charge jumps to 100%

The SmartShunt 500A works correctly while discharging (the used ampere counts up and the capacity decreases). When my Solar MPPT charger is charging the battery, the "used ampere" at the smart shunt jumps to zero and it says 100% battery capacity.

I have a Lithium SuperPack 100Ah and a SmartSolar 100/30.


Is this a problem with my settings? Is there any known issue about it?

SmartShunt
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2 Answers
Vangelis Beligiannis avatar image
Vangelis Beligiannis answered ·

Hi! The smart shunt counts the consumed Ah and gives you an estimation of the SOC. The real SOC can never be precisely measured. Discharging 10Ah with 100 Amps is very different from Discharging 10Ah with 5 Amps. So the shunt starts calculating the Ahs you give back to the battery, but if certain parametets are reached (voltage, tail current and time) it jumps to 100%.

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birdie avatar image
birdie answered ·

Hello,

Thanks for the answer.

I understand that it can't be measured very precisely. But still it should not jump back to 100% if there is only small charging.

For example: I leave the battery at night with around 60% capacity (shown by the smart shunt). When I check the shunt the next morning it is back at 100%, although it only charged a little bit from solar (probably maximum 5Ah).

The MPPT charger sets the voltage to the charge voltage of the battery, but that should not be concidered for the charge status of the battery. The current can be very low as the solar doesn't produce much energy right now (only 400Wp attached and winter), but it doesn't mean, that the battery is fully charged. When I attach my DC-DC charger, it charges the battery with 30 amp.


From my understanding the shunt should count the amps charged the same way it counts the amps discharged and not jumping back to 100% as soon as the battery is charged slightly.


I bought the smart to have control over my battery charge state and the used/charged Ah. If it behaves like this and stays nearly always at 100% regardless the real state.

5 comments
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klim8skeptic avatar image klim8skeptic ♦ commented ·

You have not mentioned any settings that have been applied. Look at charged voltage, voltage detection time....etc.

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birdie avatar image birdie klim8skeptic ♦ commented ·

These are my settings:

screenshot-20201110-124204.png

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klim8skeptic avatar image klim8skeptic ♦ birdie commented ·

You could probably set the charged voltage at 14v, and the tail current at 3%.

Worth a try.

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birdie avatar image birdie klim8skeptic ♦ commented ·

I changed it to 14,1V charged voltage, 1% tail current and increased the charged detection time to 10m. I will try the next days if the shunt works as expected.


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chrishaddon avatar image chrishaddon birdie commented ·
Hi Birdie

I have same problem, did you solve this?

Chris H

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