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william avatar image
william asked

Equalization not working

Multiplus inverter/charger 24/3000/70. I need to equalize Rolls 5000 24 V batteries. Multiplus says the batteries are floating. I start the generator manually, set the run time for 6 hours. From our CCGX I start the equalization process. The Multiplus shows that it is in the equalization process because the bulk and absorption LEDS are flashing alternately. The image shows the process starting at about 10.20. At about 12.45 the battery volts reaches absorption volts but instead of battery volts continuing to rise to about 30-31, eq volts, the charger switches to about 26.20, float volts. Specific gravity is still about 1.190.

Not sure what's going on. How can I get the eq to perform correctly?

MultiPlus Quattro Inverter Chargerequalisation
screenshot-2018-12-11-at-221906.png (132.0 KiB)
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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ commented ·

Hi William; pls start with checking firmware versions, for the ccgx and the inverter/charger.

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william avatar image william mvader (Victron Energy) ♦♦ commented ·

@mvader (Victron Energy Staff) I'm up-to-date with versions: Multiplus is 2612431, CCGX is 2.20.

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william avatar image william mvader (Victron Energy) ♦♦ commented ·

@mvader (Victron Energy Staff) You might be interested in the previous day's charging. Generator was turned on for charging, equalisation was not selected. Running for 6 hours, approx 11.30 to 17.30. Looks like absorption for 4 hours (that's the setting) then float.

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6 Answers
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hey William, perhaps you need to enable Equalize only after fully charging the battery.

Here is how it works:

  • The charge voltage is set 1V higher than the Absorption voltage (1V is for 12V systems for 24/48 V systems it is 2/4 V)
  • The charge current is limited to 25% of the configured charge current
  • LED indication: bulk and absorption blink alternating. (not on a small unit, such as a Multi Compact, that has only three LEDs)
  • Once Equalisation has started; the inverter/charger will stay in equalize for one hour. However the timer which is used to time this will only counting when the DC voltage is at or above absorption voltage minus 0.5V. (for 24/48V systems this is -1/-2V)
  • When this time is over, the device switches to float. Exception to this is when the state changed to Bulk in the mean time; due to a low DC voltage; then its in bulk again.


And check the charge state diagram: it will be more clear when the device is really in equalize mode; and when its not.


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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ commented ·

ps. a condense version of above is in the Multi & Quattro manuals.

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william avatar image
william answered ·

Thanks. I have read the Multiplus manual. I do understand that you should attempt to equalize only when the battery is fully charged.

You say 'The charge voltage is set 1V higher than the Absorption voltage'. I can set Absorption voltage: how is the charge voltage set?

The LEDs are blinking correctly in eq mode.

I note that eq only lasts for one hour when started manually using our generator. At this time of year in UK there is not sufficient sunlight to maintain eq state so we use a generator to charge and hopefully to then equalize. We have flooded lead-acid batteries, sg currently about 1.195-1.200, which need longer eq to bring the sg of all cells to the same level. Is it possible to extend the eq time?

Perhaps my solution is to firstly increase the absorption time (currently 4 hours) so that the cells can receive more charge and not revert to float too early. Is that a good idea?

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potgieter avatar image
potgieter answered ·

When I want to equalise, it stays on starting and does not go over to equalisation, any feedback ?


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Kelly Armfield avatar image
Kelly Armfield answered ·

Similarly I can't seem to achieve equalization voltage, see attached screen snip, I tried to equalize at around 1815hrs, but voltage went down instead of up.system-battery-voltage-and-current-210613.jpg

I was wondering if I need to tick the 'Use equalization' box in the VE Configure to achieve this? See current VE setup in attached screen snip.ve-configure-snip-210613.jpg

Thanks Kelly


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ve-configure-snip-210613.jpg (61.2 KiB)
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huramentzefix avatar image
huramentzefix answered ·

not sure if that still helps, your thread is more than one year old. but probably others that are passing by and are experiencing a similar problem.

I just tried to equalize with a bluesolar MPPT 150/70 solar charger with firmware 2.04.
there is a bug in the firmware, when I manually try to equalize the charger looks at the set absorption voltage, not the equalization voltage.

could be the same bug in your case?

I haven't tried auto-equalize.

the manual also states that the manual equalize stops after 1 hour. the automatic doesn't do that according to the manual, not tested though. so you would have to restart equalize each hour if it's the same in your case...

my admittedly not very elegant work-around that I just initiated is, to set the absorption voltage to the desired equalize voltage and limit the charge current to 1/10 of the capacity of the bank.
set the absorption time to "0".
If I wouldn't reduce the current my charger would be equalizing with 1/3 of the capacity.
not sure if 1/10 is good for equalization but I don't want to heat them up too much.

I am doing this with solar panels. I can just leave these settings till I see in the history that this maximum voltage has been reached today or tomorrow and then put settings back to normal.

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byahi avatar image byahi commented ·

I figured this out today! I tried the raising the absorption voltage manually trick, which made it work. However what really fixed it is the Expert mode setting for "Equalization current percentage". That was set at 3%, which for my MPPT 100/30 unit charging a 225 AH bank maxed out at 0.9A. But why was it charging at the equalization voltage at a higher than 0.9A current? I think it was choosing a minimum voltage of the absorption setting, regardless of the selected current percentage. Bumping the percentage up to 50% (15 amps) now allowed the voltage to get up to the Equalization setting of 16.2V.

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joz1975 avatar image
joz1975 answered ·

Thanks for you tip on increasing the absorption voltage manually to trick the system into using the right equalization voltage. Do you guys know if that bug in the software was fixed yet? Is there a way to bring it to Victron's attention?

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