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alex_solar avatar image

3-phase Quattro 48/10000 + BYD B-Box 10,5 L (2 units) + Fronius + Solar - off grid

Hi, we have an off-grid installation and have ordered 2 units of B-Box 10.5 LV batteries. After orderind we saw Victron blogs with next info:

Is that mean that the only way is to change the batteries for example to B-Box Pro? We plan to use it with Fronius Symo 15.0 + solar panels + Quattro 10000 (3 units) in 3 phase system.

Now we have next situation: when we turn on the B-Box L without any consumers it wors ok, after that we connect color control GX and it found the B-BoxL and show all the spec. But when we turned on th B Box L alredy with connected CCGX the battery goes into error.

So the question should we change the batteries? And why the similar B-Box pro is ok for off-grid and B-Box L is not suited?

Thank you!

CCGX Color ControlBYD
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2 Answers
alex_solar avatar image

If we don`t talk about warranty, is it possible to make it working? and what is the technical difference between B-Box Pro and B-Box L?

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The LV will work as long as there is a CCGX, it won't differentiate if it is on or off grid. However, as the components have not been sized for the power surges that can happen in off-grid, you can either have the batteries shutting down or even damaged.

To remove the off-grid variable. Please isolate the batteries from the inverters and try to switch them on, on their own and use the web portal to download the alarm history.

Even the inrush capacitor load of the Multi’s in off grid can overload lithium battery BMS’s that aren’t designed for that application and cause errors.

It’s a bad idea ignore manufacturers advice in offgrid. It isn’t just warranty, but lack of reliability and makes support and troubleshooting other issues extremely difficult.

Save yourselves ongoing grief and choose equipment that is tested, supported and recommended for the application.

alex_solar avatar image alex_solar Guy Stewart (Victron Community Manager) ♦♦ ·

Thank you a lot for answering me! Ok, now we think what can be better: change to BYD PRO (8 units x 2.5 kW) or choose Victron 25,6 200Ah (4 units)? Now we have budget only for 20kWp*hour Of course we understand that with BYD Pro 10 (8 units) we can not make output power more than 20 kWp. Datasheet shows us that in off grid, 3 phase min quantity is 18 units. But is the using of 8 units can make the BYD will broken? I thought that in case of output power more than 20 kWp BMS will cut it off.

Now the costumer has max nedded output power not more than 15 kWp. In future could be more but we explained to make batteries bank bigger. So the question: what about VE 25,6 200ah LiFePo4 batteries (4 units). Is that any requiments of min. quantity? Whould it be better than BYD Pro in amount of 8 units?

Thank you in advance!

Hi BYD!!I've got another issue similar to Alex's one...Got an AC Coupling with 2 Kostal Piko 15 kw (30 kw) with 114 panels of 270 wp. Isolated part has 3 Victron Quattro 15 KVA (10 Kw) on 3 phase config and 2 Battery Pro 13.8 (27,6 kwh of storage)...Also have a generator of 100KVA,s....I'm aware that it's suppose to have 7 modules of these batteries to accomplish minimum composition...But the thing is that customer needs into the next days have the installation working...

Quattro inverters are configured with PV Inverter assistant and all the parameters seems to be Ok...So when I turn on the batteries they cannot make the inverters start. Alarm is on, makes 4 whistles and turns off... If I turn them on with generator, they do it, charging the battery perfectly, and if I connect any load, the battery discharges inverting current and satisfying what is demanded... but if I turn off the generator the system keeps working for 5 minutes and then batteries switch off and inverters do the same.

So, at least I try to keep the system working with the generator but with it working, Piko Inverters(With ET340 meters connected) don't generate because they read unstable frequency system...(Because of generator's Fq)...Italy CE 21 grid system is configured which is supposed to be the best one for the case...So If I turn the generator off, then Piko produces and feeds loads but does not charge batteries... Eventually after 5 minutes (Like I explained before) batteries switch off so the whole system does....

Resuming I suppose all these malfunction comes from the insufficient storage of BYD batteries, but I need to know if there is a way to make the system works, doesn't matter batteries warranty or non using maximum performance..If there is any way to cheat on (limit) inverters to make batteries work...If that's not possible, at least make the Piko PV Inverters avoid Frequency issues and work with generator connected, because that has nothing to do with batteries issue.

There must be a way....

Really appreciate finding a solution.

Thanks in advance.

Best regards

In my opinion, 21 ( 10.5+10.5) KWH is too small for 30(10KW x3) KW inverter system in case of offgrid use - Typical ratio KWp/KWH for LIfepo4 are betwen 0.5 to 0.7 for many brands so for 30 KW system you need between 42 to 60 KWH of Lifepo4


Did you check the min capacity recommendations for offgrid use by BYD - 2.0 min battery sizing requirements

https://www.victronenergy.com/live/battery_compatibility:byd_b-box

in your case of off-grid minimum 6 units of 12.8 BYD pro or 18 units of 2.5 KW Pro are recommended.

BYD_service avatar image

The Bbox LV is not approved for off grid use so unfortunately it wouldn't be covered by the warranty.

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