question

billys1337 avatar image
billys1337 asked

Multiplus charge cycle not resetting.

Hey all.
Hoping for a bit of advice.
My system is
Multiplus 12/1600
MPPT
Smartshunt (DVCC enabled, voltage sense and current sense enabled).
Cerbo GX with VRM

I have been tweaking my system to get a multiplus and MPPT charger to work together while prioritizing charge from the MPPT and have achieved this by setting the MPPT set voltages +0.05v higher than the multi, this has been working good.
My problem is, the multiplus will bulk, absorb, then float, at night when i turn off the power it switches to invertor mode and runs all night, the batteries get down to about 12.5-12.6v.
Then the next day when I reconnect mains power the multi will just charge in float and does not start from bulk.
I have to reset the VE.Bus system in VRM to get it to bulk again.
The MPPT works as expected, full cycling every day
One think to add, due to my battery type I have set the absorp voltage to 14.2 rather than 14.4, might this have something to do with it? the batteries not getting low enough compared to absorp, to trigger it to bulk again?
I don't understand why this is happening and would love to be pointed in the right direction.
Thank you

Multiplus is set on adaptive absorption time 2 hours
MPPT is set on adaptive absorption time of 2.5 hours
Float voltage 13.65 on MPPT / 13.6 on MP
Absorp is 14.25 on MPPT / 14.2 on MP

MultiPlus Quattro Inverter Chargermultiplus ve.bus
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1 Answer
JohnC avatar image
JohnC answered ·

Hi @billys1337

Try adjusting the Repeated Absorption Interval in the Multi's charge settings. It doesn't work off a solar day like an mppt, you have to tell it when to recommence a full charge cycle.


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billys1337 avatar image billys1337 commented ·
Ok thanks JohnC, I will try this. I thought repeating absorption would only come into effect if the charger is on float for long periods of time without leaving float. I thought the fact it was going into inverting mode and/or voltage drop would trigger itself to reset.

Ive set it to 0.5 days now to test.


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