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mvn avatar image
mvn asked

Charging Lifepo 48V with Skyla TG 48 as power supply for a Smartsolar MPPT 150/70 VE can?

Want to put my Multiplus II 5kW (3phase) with 44kWh Lifepo4 48V pack OFF-grid; feeding everything in the house: No more peak-taxes from the grid :) (Belgium).

In summer time the pack is charged from multiple Smartsolar and RS chargers; works fine.

In winter time I would like to charge my 48V pack from the grid, but not using the chargers in de Multiplus (because then I am ON-grid...), so I would use a charger like the Skyla TG 48/25 to charge the batteries (nice and slow with 1450W max, thus making charge of 35kW/day); that way my Multiplus configuration stays OFF grid.

Problem here: I want an absorption voltage of 55,2V and float voltage of 53,6V. The Skyla, not originally designed for Lifepo4, outputs 57V and 53V, and there is no way to control it externaly.

Question: Can the Skyla TG48/25 be used as a power source to feed a Smartsolar MPPT 150/70 VE-can that will charge the batteries? This way I can adapt my absorptions and float voltages, and even cut power on/off to my Skyla using the build in relay. Would this work and will the 57V of the Skyla start the Smartsolar MPPT up? (the +5V story...).

2nd question: can the Skyla be adapted ( internal adjustement?) to 55,2V and 53,6V output voltages? Powering it on/off could perhaps be done with a relay from the Multiplus or Cerbo GX?

Thanks for all suggestions. Would be easier if Victron gave the Skyla the intelligence of the smartsolar chargers....

MPPT SmartSolarSkylla48v battery
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2 Answers
Michelle Konzack avatar image
Michelle Konzack answered ·

Do NOT buy the Skyla and use the MultiPlus you have.


Simply do following which is LEGAL in all EU countries:


Disconnect the FuseBox from the house from the Box where the cable from the Grid come in, to be more precise after the main fuse/switch.


Here you install a WALL mounted red CEE socket with 32A (= 12,6kW @400V).


The 3 ACin of the MultiPlus you connect to a Cable H07RN-F 3G6 and put a red CEE plug with 32A on it.


Since the house is NOT MORE fixed connected, plugging in the CEE can not more considered as an On-the-Grid connection, because you need it only for charging the batteries.


Have fun with it and super fast charging from your MultiPlus'es.


I have done this workaround in France, Germany and Estonia.


Note: In Germany and France you MUST have the Grid cable in the house, otherwise they reject the building permission. 8-P


Happy new year

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mvn avatar image
mvn answered ·

Thanks for the advice, but I am not sure this is allowed in Belgium...connecting the multiplusses via a CEE socket is still allowing the MPPT solar panels to feed back in the net... My grid connection is 3phase 20A, thus 3x20Ax230V=13,8kW, the tree multiplusses of each 5kW have 15kW capacity...exceeding my grid connection. Also, on the grid side, I already have 5kW ACPV, possibly feeding in also.....In Belgium, without special equipment and costly 'netstudy' it is not allowed to feed in more than 10kW.

By charging with 48V from the grid I can never feed in, only the 5kW ACPV.

So still interested if the above idea world work (using Skylla or other powersuply feeding a Smartsolar MPPT.

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