question

John Berger avatar image

Why is my maximum State of Charge (SOC) stuck at 85%?

The Problem: SOC from the inbuilt battery monitor never goes above 85%, climbing down from 100% at installation. (I think the rotary switch is set to Position 1 battery type - flooded.)

Here's my offgrid setup, installed 2 weeks ago:

PV Panels: 15 Jinko 270w panels in 5 strings of three (in series)

Inverter/Charge controller: Victron EasySolar 48/5000/70-100 MPPT 150/100 Color Control

Batteries: 16 Trojan T105 flooded cell (2 banks of 8 x 6v in parallel) with combined 20 hour capacity of 450ah, or 10 hour capacity of 414ah


Any advice greatly appreciated. Thanks!

BMV Battery Monitor
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3 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

There is information about this in Section 2.4 Battery State of Charge (SOC) of the CCGX manual.


2.4.4 Details on VE.Bus SOC


While the Inverter/Charger is in bulk, the SOC will not rise above the value as set in VEConfigure3 for the “State of charge when Bulk finished“ parameter on the General tab; default 85%.


In a system with Solar chargers, make sure that the Absorption voltage as configured in the MPPT is slightly above the same setting in the inverter/charger. The latter needs to recognize that the battery voltage has reached the absorption level. If it doesn’t, the SOC will be stuck at the earlier mentioned End-of-bulk percentage, default 85%.


Update your firmware


With ESS, the MPPT follows the charge curve of the multi. Ie the MPPT ignores it's own charge settings. There was a bug there that caused the multi to not recognize that the MPPT had finished bulk and started absorption. This has been corrected in firmware and assistants updates, and all should be brought up to date.


Without ESS, to have a proper SOC in the Multi, you indeed need to make sure that the Absorption voltage as configured in the MPPT is slightly above the same in the Multi.

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John Berger avatar image
John Berger answered ·

Thanks Guy for the great quick answer! I had read in the CCGX manual, "State of charge when Bulk finished“ parameter on the General tab; default 85%.

1. Does this mean it's ok to change this setting in VEConfigure3 to a higher value, say 95% or even higher?

2. Where do I check that the Absorption voltage as configured in the MPPT is slightly above the same setting in the inverter/charger? Is that done in the VEConfig3, Colour Control or VE Connect? (Sorry, I'm a bit new to this.)

3. How do I update the firmware? Can you please briefly outline the correct procedure?

Thanks so much for your help.

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Please create new questions, with clear titles, for each of those and I will answer them there.


This will help others more easily find exactly what they are looking for. One question only per post please.

Elimac avatar image
Elimac answered ·

Hi,

This is related to a similar question I just recently posted, take a look:

https://community.victronenergy.com/questions/569/incorrect-soc-monitoring.html

In deed, changing the MPPT voltage a little higher than that of the Multi has helped!

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