So far, a few issues. (Gettit?) Cough - Sofar ME3000 SP

WIAWSNB

Sooo, I'll stick with what I have at the mo', but wish to understand what the manual 'default' battery settings mean, please.

I have the parameters of the M48112-S, and I have the 'Default' parameters to be set. I understand;

1. Battery Type - 'Default'
2. Battery Capacity - 112Ah (just one battery at the mo')
3. Discharge Depth - 80% (will go up to 90% later)
4. Max Charge (A) - 55A (3kW max PV generation, charging at 54V max)
5. Over (V) Protection - No idea, but set at 55V
6. Min Discharge (V) - No Idea, (but set at 48V)
7. Max Discharge (A) - 50A
8. Low (V) Protection - No idea, (but set at 48V I think)
9. Max Charge (V) - set at 55V - won't go higher, but I'm ok with that.
10. Empty Charged Voltage - No Idea.
11. Full Charged Voltage - No Idea.

Could you explain the 'No Ideas', please? And is everything else looking ok? Thanks 😁

QrizB

Here's where I shared some settings, based on the ones that work for me:

https://forums.moneysavingexpert.com/discussion/comment/81983681#Comment_81983681

Looking at those and comparing to yours:

• Over V protection - yours seems to be set too low.
• Max charge V - yours seems to be a bit too high.

Re the "no idea", I've got empty set at 48v and full set at 56v. These seem to work!

WIAWSNB

https://forums.moneysavingexpert.com/discussion/comment/82021748#Comment_82021748

Thanks QrixB.

Yes, I knew you'd given me some figures to work with, and that was my starting point. But I wished to understand the difference between, say, 'Min Discharge V' and 'Low V Protection', and even 'Empty Charge Voltage' for that matter!

Max Charge V is at 55V, but the 'S' will go to over 56V, apparently. Is 55 still too high, do you think?

I don't think 'Over V Protection' will go higher than 55V.

QrizB

Based on my fiddling about (so please don't treat as authoritative):

Minimum discharge is the voltage at which the inverter stops asking the battery for power, if it hasn't already cut out on SOC.

Low V protection is the voltage at which the inverter will automatically start to charge the battery.

Empty voltage is the notional 0% SOC voltage.

Max charging voltage for a LFP battery is usually quoted as 3.65 volts per cell (58.4v for a 16S battery) but 100% SOC "at rest" (not charging) is only 3.4 volts per cell (54.4v for 16S). As I'm not using a comms cable, the Sofar doesn't know when the battery is full and won't drop back to 54.4v so I've set my charging voltage low enough that I'm not going to overcharge my battery and damage it.

Charging to 54.4v still gets you to >90% SOC which is good enough for me.

My Over V protection will go to 58.4v (3.65 vpc) so that's where I've set it. My battery should never get that high but it's a backstop!