camelot-forum.co.uk

Tinbum wrote: ↑Fri Mar 31, 2023 4:11 pm

Stinsy wrote: ↑Fri Mar 31, 2023 2:23 pm

ALAN/ALAN D wrote: ↑Fri Mar 31, 2023 2:15 pm Thanks Gents.

He has got P.V. South / East / West.

Ref “ Arrange the batteries into a single 16s3p pack with interlinks and an active balancer. “

Three balance systems. One on each bank. Then connect the three banks in parallel at the 57 volt cells. ?

Or connect each cell in parallel on all three banks with one balance system. ?

Just one balance system is the most economical solution. You only need thin wires paralleling up each cell to its buddies in the other strings because you’re only expecting teeny amounts of current.

Stinsy and I tend to disagree on the best way of doing this. I would have a BMS on each of the 3 sets of batteries. Personally I think safety features are required and communication with the inverter. The word 'expecting' worries me.

You could have one set of batteries for each inverter or you could parallel them as one pack. Having separate packs could result in heavier or lighter use between packs.

I’ve seen the links with fuses on some installs. There are no hard rules, you have to decide for yourself what needs fusing.


I have seen on here and other places people experiencing undesirable situations having several battery packs. Eg one pack at 100% and the other empty. Obviously there is no right and wrong different system designs have their own pros-and-cons.

The important thing if you use multiple units is you need to utilise the "Freeze CT" function immediately after commissioning. If they are second hand units, they may need a firmware upgrade to get that function. Otherwise they auto calibrate the CT clamp direction every time they come out of standby. Thats no problem if you only have one unit but with multiple ones, inevitably sooner or later one goes into charge mode and the other goes into discharge mode as inferred by Stinsy.

nowty wrote: ↑Sat Apr 01, 2023 10:53 am Otherwise they auto calibrate the CT clamp direction every time they come out of standby.

I thought it was startup.

nowty wrote: ↑Sat Apr 01, 2023 10:53 am inevitably sooner or later one goes into charge mode and the other goes into discharge mode as inferred by Stinsy.

That won't happen with the extra CT's.

nowty wrote: ↑Sat Apr 01, 2023 10:53 am The important thing if you use multiple units is you need to utilise the "Freeze CT" function immediately after commissioning.

Yes - good advice.

Tinbum wrote: ↑Sat Apr 01, 2023 12:33 pm I thought it was startup.

From my previous experience, it was:

• Mains off/on
  Battery off/on
  Change of work mode

I made some installation notes here: https://www.setfirelabs.com/building-au ... -inverters

Tinbum wrote: ↑Sat Apr 01, 2023 12:33 pm ..inevitably sooner or later one goes into charge mode and the other goes into discharge mode as inferred by Stinsy.

That won't happen with the extra CT's.

I think it will, although both will either be right or wrong. And regardless of whether you are using separate or shared CTs.

All the unit seems to do for its direction routine is look at the mains current direction, and assume you are importing. The manual says to ensure you are importing at least 200W. If the routine is triggered when you are exporting, the direction will be wrong.

jonc_uk wrote: ↑Sat Apr 01, 2023 1:59 pm I think it will, although both will either be right or wrong. And regardless of whether you are using separate or shared CTs.

All the unit seems to do for its direction routine is look at the mains current direction, and assume you are importing. The manual says to ensure you are importing at least 200W. If the routine is triggered when you are exporting, the direction will be wrong.

Yes but only if its triggered which it shouldnt be in auto.

I'll have to try a change of work mode.

It won't happen from standby or single inverters would all be doing it.

jonc_uk wrote: ↑Sat Apr 01, 2023 1:59 pm

nowty wrote: ↑Sat Apr 01, 2023 10:53 am The important thing if you use multiple units is you need to utilise the "Freeze CT" function immediately after commissioning.

Yes - good advice.

Yes, last thing you want is a power cut to send them all out.

Has anybody tried the 'Greeningme' arrangement where the the mains connection to the second battery inverter is wired through the mains CT of the primary unit and the secondry unit is wired conventionally with the CT just round the incommer.

Incidentally does connecting two inverters to one common battery stack really work? How do the two inverters communicate?

Hi
Is there anyone out there using a sofar ME3000sp inverter with lifepo4 batteries
i have listed settings i am using at the moment
i have no communication between the batteries and the inverter like pylontec use
i have a jk bms balancer on each battery bank
wondering if anyone has any ideas for the best settings for the inverter
i have three battery banks of 53v x 304ah
my settings at the moment are

DEFAULT BATTERY
BATT CAPACITY 912AH
DISCHARGE DEPTH 80%
MAX CHARGE 52A
OVER PROTECTION VOLTAGE 58.5
MAX CHARGE VOLTAGE 58.4
MAX DISCHARGE 52A
LOW VOLTAGE PROTECTION 42.5
MIN DISCHARGE VOLTAGE 46
EMPTY DISCHARGE VOLTAGE 44
FULLY CHARGED 55V

If any different ideas for the settings please advise

many thanks
grumpy

I recommended these changes to Alan/Alan D a while back for a 16 cell LIFEPO4 system. Its not 100% clear from your post about how many cells you have but I note you have mentioned previously you ordered batteries for a 16 cell system.
https://camelot-forum.co.uk/phpBB3/view ... 140#p30140

He may have refined them since through experience, so maybe if he’s reading this, he will add an update. There are also others with similar batteries even though not the same inverter who may want to offer their experience too.