Two Smart Solar controllers with VE.Smart Networking enabled. Should automatic equalisation work?

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johnhaus asked Jan 6, '24

Two Smart Solar controllers with VE.Smart Networking enabled. Should automatic equalisation work?

Small system (off-grid house): 12V Sonnenschein gel battery (600Ah), two Victron MPPT 150|60 SmartSolar controllers, 4 solar panels and SmartShunt. The two solar controllers have identical settings except for equalisation. One has Automatic equalisation 'Every 30 days' (fixed time, 2 hour duration), the other has Automatic equalisation 'Disabled' - as recommended for multi-controller installations, only one controller should have equalisation enabled. I recently enabled VE.Smart Networking and verified that absorption and bulk times are now the same for the two controllers.

What happens with equalisation when controllers are networked and only one controller has equalisation enabled? It's now over 30 days since the last equalisation and no equalisation has occurred.

MPPT SmartSolar VE.Smart Network equalisation

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snoobler commented · Jan 12 at 03:05 AM

I'm just guessing.

Given that VE.Smart coordination is based on a randomly selected master, I don't expect that it will ever engage unless the one set to equalize happens to be the master.

I can't find that guidance. It certainly makes sense for uncoordinated MPPT settings, but does it apply to installations where there is charger coordination?

https://www.victronenergy.com/media/pg/VE.Smart_Networking/en/synchronised-charging---further-details.html

Synchronising the chargers works in a master-slave manner. The chargers will elect a master among them and that master will be the one to dictate the charge algorithm. As the master cannot be determined by the user, it is important to make sure all chargers belonging to the same network have the same battery settings. To know more about the battery settings and some other information

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johnhaus snoobler commented · Jan 12 at 06:11 AM

Thanks @snoobler for the reply. My guess matches your guess. I'll re-check the solar stats in a few weeks time. I'm thinking that I'll disable the smart networking.

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Answer 1 · 2024-01-12T05:12:50Z

Paul B answered · Jan 12 at 05:12 AM

You should never equalise gel ,agm, batteries. Only flooded lead acid cells need equalising

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johnhaus commented · Jan 12 at 05:49 AM

Thanks for the reply, The manual suggests it's required.

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Alexandra ♦ johnhaus commented · Jan 12 at 05:53 AM

@JohnH.aus

Just check if the equalisation voltage is meant to be higher. Sometimes the manuals really mean a longer absorption time (since equalising charge can mean cell balancing). Usually it is low current at this stage but held there at the top voltage longer.

Gel can bubbles in the gel against the plates when equalised.

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johnhaus Alexandra ♦ commented · Jan 12 at 06:22 AM

Thanks @Alexandra for the reply. The Sonnenschein/Exide Gel-VRLA Batteries manual says 14.4V. It's an old publication so maybe there's been a change in thinking. Batteries are 9 years old. Switched to Victron equipment a few years ago and the installer set equalization to 14.4V, 2 hour duration, 30 day interval.

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Alexandra ♦ johnhaus commented · Jan 12 at 07:10 AM

Is there temperature monitoring on there at all?

I do agree with @snoobler definitely need to understand a bit better the requirements or the reasons for the equalisation.

I see it mentions 1.2A for every 100AH for 4 hours on a 48v system.

1.2A on 600AH cells is 7.2A. to be kept up for that period. Probably less time for a 12v system since there are less cells. Definitely need to be careful of overcharge on gels. (The bubbles). My first gels battery I ruined because of not knowing this.

I do know on Victron mppts they will only equalize after a full charge cycle is completed (so already fully charged). But if the battery for any reason was discharged, it considers a new cycle. It is mentioned in the manual somewhere.

So with solar unless the system is totally idle it is difficult to get an equalisation charge done. It is possible besides the master not being the master on that date, that this happened as well. Just guessing as I don't know how you use your system.

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snoobler johnhaus commented · Jan 12 at 06:20 AM

No. Not everything Victron says is gospel without qualifiers.

The only batteries that should be equalized are those that the manufacturers say can be equalized. PERIOD.

By default, this is flooded. In some rare cases AGM batteries have a very limited equalization cycle that usually just involves an extended absorption period at the absorption voltage.

Note that YOU are asking about AUTOMATIC equalizations, which are disabled by default - for a reason. Victron doesn't want to be held responsible for killing user's batteries because users don't know what they're doing.

Bottom line: You shouldn't be equalizing unless YOU fully understand the process and how it applies to your specific brand and model of battery.

IMHO, automatic equalizations should never be used. Most manufacturers have criteria for when to run an equalization charge. Run them manually when those criteria are met.

Again, flooded lead acid batteries are essentially the only batteries that benefit from or need equalization charges. Equalization charges will destroy SLA, GEL and AGM batteries unless done in accordance with the manufacturer's recommendations, and very few do.

I recommend you research your battery's equalization requirements (or lack thereof) rather than go off a generic comment in a manual for a feature that is disabled by default.

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Fideri johnhaus commented · Jan 12 at 11:01 AM

@JohnH.aus

That's not my understanding of the quote. It says nothing about the types of batteries. The writer could well be talking about flooded lead acid batteries only.

Fideri

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johnhaus Fideri commented · Jan 12 at 11:08 AM

The text relating to equalisation is quoted from this manual. Manual is published by Exide/Sonnenschein. I did include that in the earlier post but the forum didn't display the image.

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Answer 2 · 2024-01-12T08:04:54Z

Paul B answered · Jan 12 at 08:04 AM

DO NOT equalize Gel and AGM.

This in my opinion is a general rule for MOST lead acide batteries unless otherwise stated by the manufacturer. and even then be very very carefull

GASSING IS BAD
Equalization is not good for batteries because it requires eventual replacement of the electrolyte. It is a necessary evil required only for flooded batteries to mix up the electrolyte if the battery has been sitting unused. Equalization is only required if the battery is sitting for weeks at a time. Vehicle motion also mixes the liquid, so equalization is not needed nor good for the battery if it is frequently in motion. Stratification is where the heavier, more acidic solution sinks to the bottom of the cell. Equalization produces bubbles that mix up the top and bottom. These hydrogen bubbles are replaced by adding water, or with a sealed battery, eventually recombined with the electrolyte. With a totally sealed battery, you may see the sides bulge, which could be normal.

GASSING IS REALLY BAD FOR GEL AND AGM
Gel and AGM cells do not have a free-flowing liquid solution and equalization will only cause gassing, not mixing. Gassing is not necessarily good because water will need to be replaced. However for GEL and AGM, the gas will either:

- If the gas pressure is BELOW the valve cap set pressure point it will eventually recombine with the gel or AGM electrolyte.
- If the gas pressure is ABOVE the valve cap set pressure it will BLOW out of the cap. You will hear the hissing of hydrogen gas. Not good since you cannot replace the electrolyte. A little gassing will not destroy the battery, but continued equalization will.

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