peukert Exponent vs SOC

[sunshine_eggo]

Mind clearing something up for me? Wouldn't the voltage need to be over a certain point, AND the current to drop for the 100% to be synced?

Yes. That's how it works. Voltage over the charged value. Current under the tail current % for the set time period (3 min by default).

Wouldn't this avoid the false sync to 100% when the current drops due to low solar only?

Default config is 0.2-0.3V below FLOAT.

For solar charging, you use ABSORPTION. When variable solar drops below tail current when the battery is not nearly fully charged, voltage will typically drop below the "charged" voltage and avoid false sync.

10. Troubleshooting

www.victronenergy.com

See 10.3.11.

It is also possible that the battery monitor synchronises too early. This can happen in solar systems or in systems that have fluctuating charge currents. If this is the case change the following settings:

• Increase the “charged voltage" to slightly below the absorption charge voltage. For example: 14.2V in case of 14.4V absorption voltage (for a 12V battery).
• Increase the “charged detection time” and/or decrease the "tail current" to prevent an early reset due to passing clouds.

 

[hogback]

Thanks.

So if I operate scc for 55.2 Absorb, 53.6 Float, the idea is that 53.3-53.4V is too much possible reduced SOC for a smartshunt sync to 100% (assuming cloudcover caused the reduced current), and that a setting for 100% smartshunt sync at 54.9-55.0V would help in two ways. One, the reduced current from cloudcover would cause the V to drop to the no-load V (avoiding 'false' sync), AND that 54.9-55.0V is pretty much a determiner of 100% in any case.... right?

 

[sunshine_eggo]

Thanks.

So if I operate scc for 55.2 Absorb, 53.6 Float, the idea is that 53.3-53.4V is too much possible reduced SOC for a smartshunt sync to 100% (assuming cloudcover caused the reduced current),

Yes. High likelihood of a false sync with significant error (20% or more is common). If you still have sufficient sun to fully charge the battery, no harm. If it's a really bad day, the last thing you want is 100% indicated when actual is 60-70%.

and that a setting for 100% smartshunt sync at 54.9-55.0V would help in two ways. One, the reduced current from cloudcover would cause the V to drop to the no-load V (avoiding 'false' sync), AND that 54.9-55.0V is pretty much a determiner of 100% in any case.... right?

1) Yes.
2) Yes-ish.

False syncs can still occur. The goal is to limit the total error. You might still false-sync, but 100% indicated vs. 95% actual is not a big deal. Even when 100% is indicated, charge can still occur, and the shunt just holds 100% allowing actual SoC to catch up if charging is sufficient.

 

[hogback]

Makes sense - thank you.