jbakuwel avatar image
jbakuwel asked

Charging Narada LCSS (lead carbon super capacitor) batteries with an AC coupled MultiPlus


I'd like some advice how I can make sure that the MultiPlus is programmed correctly for the Narada LCSC (Lead Carbon Super Capacitor) batteries. I've derived the two columns for the MultiPlus in the table below from the graph in the MultiPlus manual. The voltages for the batteries are derived from tables in the Narada manual.

The temperature compensation of the MultiPlus (currently) cannot be changed but it seems the differences (primarily at the lower and higher ends of the temperature spectrum) are significant. So far, the batteries have never reached temperatures above 25 deg/C so I'm not too worried about the higher temperatures. But the batteries surely drop to below 10 deg/C at times in the winter. What can be done to match the MultiPlus to these batteries?

My 2nd question is about the effect of ticking Storage box on the charging curve. In a fully off grid situation, the batteries never get "stored", they are in active use every day of the year. Hence I've disabled "Storage". I did notice a difference in the graphs though, which I would not expect. Why would the charging algorithm be different for the "non storage time" as well (as for the time the batteries are stored)? And am I correct in assuming that the "Repeated Absorption Time", "Repeated Absorption Interval" and "Max Absorption Time" do not apply when Storage is disabled?


A1 B D E F G H I J K
3 Temp (deg/C) Absorb Float
Absorb Delta Delta formula Float Delta Delta formula

5 <=10 58.80 56.40
56.40 -0.60 (G5-G8)-(D5-D8) 54.60 -1.28 (J5-J8)-(E5-E8)
6 15 58.00 56.00
56.40 0.20 (G6-G8)-(D6-D8) 54.60 -0.88 (J6-J8)-(E6-E8)
7 20 57.60 55.20
55.80 0.00 (G7-G8)-(D7-D8) 54.24 -0.44 (J7-J8)-(E7-E8)
8 25 57.00 54.40
55.20 0.00
53.88 0.00
9 30 56.40 54.00
54.60 0.20 (G8-G9)-(D9-D10) 53.52 -0.04 (J8-J9)-(E8-E9)
10 35 56.00 53.60
54.00 0.20 (G8-G10)-(D8-D10) 53.16 -0.08 (J8-J10)-(E8-E10)
11 40 55.20 52.80
53.40 0.00 (G8-G11)-(D8-D11) 52.80 -0.52 (J8-J11)-(E8-E11)
12 45 54.80 52.00
53.40 -0.40 (G8-G11)-(D8-D11) 52.80 -1.32 (J8-J12)-(E8-E12)
13 >=50 48.00 48.00
53.40 -5.00 (G8-G13)-(D12-D13) 52.80 -5.32 (J8-J13)-(E8-E13)

battery chargingtemperature compensation
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1 Answer
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

If you want a more precise temperate compensation for finishing charge, I think the best thing to be done to the get a Victron SmartSolar DC MPPT with a Smart Battery Sense.

You can adjust the temperature algorithm more precisely on that.

The bulk of your charge can still be done with the AC coupled solar.

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