Growatt 24v 3000 with Lead Acid - Equalization voltage

[01SATSA]

Hi all,

I seem to have made a newbie mistake when buying my solar equipment.

I purchased a Growatt 24v 3000 and paired it with (4) x 6v Rolls L16-HC Lead Acid Batteries.

The issue I have is that the Growatt EQ voltage maximum is 29.2V but the batteries need 31.6V to equalize according to the manufacturer.

I'm not certain how to address this easily, my thinking is that I have 4 options:

1- Buy an external 24v charger that I can run from the GRID or Generator which will support 31.6V in the equalization mode
2- Trade my Growatt for another all in one that may support the right EQ voltages
3- Upgrade from Lead Acid to Lithium - but that is very expensive, over 4000$ CAD.
4- Move my solar panels back over to my Outback FM80 and use the Growatt for only inverting loads

Options 1, 2 and 3 will cost more money but option 4 means I spend money on an all in one that isn't going to be all in one in the way I deploy it.

Option 1 is likely the most cost effective but finding 24V chargers with the right specs seems challenging - any recommendations?
Option 2 will be costly as it means buying another all in one and trying to resell my used Growatt
Option 3 is the most expensive option and can't be funded by this project at this time so it's not really an option
Option 4 Is an option but the reason I moved from individual components to an all in one primarily was so I could monitor the solution with Growatt Shine. I would loose the ability to monitor incoming power from the panels if I went this route (without spending more $).

Given the above, option 1 seems best but I would like your thoughts.
Also, if you agree that option 1 may be best, would you have any recommendations for chargers that will meet the required EQ voltage but not cost an arm and a leg?

Thanks all,
01SATSA

 

[mikefitz]

The equilisatin is needed infrequently, Rolls suggest 3 to 6 months. Since the process is carried out on fully charged batteries the current is low, less than several amps. Continual monitoring of SG is advised and the duration may be a few hours.
Either a seperate solar controller suitably programmed for the required vottage or an AC charger ( since you have grid available).
Victron Smart IP 22 charger range are fully programmable and can operate in charger mode with reconditioning or power supply mode.

Mike

 

[01SATSA]

Thanks for the reply. Yes, I'm ready to monitor the SG once I can get the EQ voltage sorted out.
Any idea how much current draw may or how to calculate it, I'd like to ensure I the AC charger outputs enough. I'll check that Victron now, thanks for the suggestion!

 

[drewboz]

I've been grappling with the same thing with my growatt and am considering something in terms of just using the growatt as my inverter and getting a midnite or other charge controller that is much more suited to lead acid batteries. The other issue I am having is that my batteries hang out at absorption for way too long. The algorithm that they use seems less than ideal for lead acid. I much prefer the outback and midnite's ability to adjust the time on the absorption. The growatt is awesome in terms of its power output, but seems more suited for AGM, or Lifepo.