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Hi all.
I am about to do the first charge on the battery bank and confused between the multiplus documentation and the batteries (SOPzS 2v 605Ah in 24V).
I understand I should use forced absorption mode. But the Multi manual, the absorption time can be up to 8h
But from the battery manual , for commissioning, I understand I need to set min 24h absorption time.
Have I gotten it all wrong?
Thanks!
Mike
Hello Mike, usually the batteries are already commissioned by the provider / reseller. It is almost a plugg and play step. Yours are OPzS, and should usually have a 1.24 acid density when charged. Chose the right type of battery in your Multiplus, and you should be fine with that.
In the meantime, buy a refractometer to check the acid density, so you will be sure that your batteries are fine, correctly loade, or need an improvement (equalization when "fully" loaded, but density too low, menaing they are sulfated).
Michel
Is there any Multi setting on the gassing charge current limitation? It mentions 0.3XI10 = 18amps
It seems I have to wait for the USB MK3 cable since while the absorption voltage matches at 30v, the floating should be 28.8v while the Multi set by dip switches is 27.6v
Hi Mike, I finally was able to check my mppt configuration : Absorption is set to 30.2VDC, and with losses, temp compensation brings around 29,8VDC to my OPzS battery bank (24V, 1000Ah C10). Float is 27.6VDC.
For the commissionning go with 20A, because of the losses, and consider doing it during several days if you are 100% off-grid : check the time during the PVs are able to provide 20A continously, then disconnected your inverter/charger, and do the same for the period needed according to the instructions you have (typically 8h x minimum 3 days). If you are still connected on grid, perform it during the mentionned period, probably by resetting the absorption time on the multiplus.
I hope it helps you a little bit with your new setup.
Michel
I was wondering, if I simply use the default Adaptive charging+BatterySafe mode with the dip switch mode of 30.0v abs, 27.6 float and given the multi is 50A * 75% default = 37.5A < 10% of bank Ah, for 8h, it should be ok for the commissioning no?
Perform a check at least 1x per month, it will save you ruining the 1st set of batteries ... (It happened to me... not charging them at the 30VDC, but less !)
Have fun ! Michel
I am sad today..I checked all the cells individually, each had exactly 2.05v. When patched all together, I measured exactly 24.6, so I plugged the multi set to 30v absorption as per my SOPzS specs and switched to charger. The charger led is lit permanently, but the charger is not drawing current from AC, I only see 15w drawn from my plug..measuring the poles on the bank I see 28.9v when connected. 7h later still the meter did not show any more current drawn. switched off charger and measured, still 24.6v... While the multi does make a "charging" sound when in charge, the batteries are not heated at all either...any ideas? After first attempt I disconnected the temperature sensor.
Thanks..
I know that when my batteries had a 80% discharge (normal use to make them work), it took me 3 - 4 days to recharge them and at the beginning it was almost no power absorbed. IT is normal, as when discharged, the electrolyte is almost water if I remember right, and it needs time to dissolve it from the plates into it, and getting a better absorption.
Silly question: If the cable crimps where not properly crimped , since I get the voltage, wouldnt they overheat?
Hi Minas, get a refractometer, and hydrometer is useless ... I did destroy a set of batteries because of using it and not getting the precise measurements.
I have had also my cables heating (it is normal, but again, it should not be something crazy), because they were not perfectly adapted (use welding power cables, they are great for carrying huge amounts of Amps). Also if the connectors are not well crimped, you can have heat losses at the connections.
