On-grid domestic battery storage

1961Nick

Zarch wrote: »

The data geek in me would be very interested in seeing the screens/data/stats coming out of the Sofar Inverter and Pylontech batteries. (SolarMan website and app?)

If I ever did take the battery plunge i'd need to know I could get to the underlying stats. :rotfl:

There's so much data that you'd need a username starting with "Z" to understand it all.;)

http://home.solarman.cn/login.html

It's free to register & it'll give you a good idea of what's available.

Martyn1981

mmmmikey wrote: »

Interesting choice of words "useful (warranted) life of the battery" - but maybe I'm over-analysing / reading too much into them....

I would expect the useful life of the battery to extend well beyond the warranty (as it does for most things you buy). For example, the expected life of the PowerVault batteries is 6000 cycles, which at 1 cycle per days is 16ish years, but the warranty is for 10 years.

If the thinking is that you want to see your money back in the warranty period so you've still got time to see a profit before the batteries reach end of life, I can see the logic there. But if your doubtful of them lasting beyond the warranty period, that does seem somewhat over-cautious to me?

Be interested to hear views on this?

That might be partly my fault, as I've said a few times how I'm pricing things up based on warranty. It's not that I don't expect them to last longer, it's just that it's early days still, we haven't seen how the kit(s) work, and also need to be a little wary as some companies/suppliers probably won't be around in 10yrs.

But I'm not disagreeing with you, I've openly admitted that I'm being a bit unfair, just overly cautious as we are still in the early days.

6,000cycles no longer seems rare, and I'm sure I've seen 10,000 mentioned at least once. I suspect that a quality battery, especially if operated between 20% and 80/90% will be seen to handle 10,000 cycles with reasonable capacity loss. But obviously I'm speculating now.

I'd certainly suggest oversizing by 20% regardless, that way you can reduce the 'harm' to the batt, and after 10+yrs still have the original desired capacity, perhaps more - or that might be false economy when in 10yrs time batts cost a pittance?

mmmmikey

Martyn1981 wrote: »

6,000cycles no longer seems rare

Z made an interesting point about this earlier. It's one thing having individual cells that will still hold 70% of the energy after 6000 cycles but it only takes 1 of them to fail to render the whole battery useless - i.e. the MTBF of individual cells is a factor, as well as the various electronics. Time will tell but I'm now thinking I may be being over-optimistic. As is often the way, reality may end up being somewhere in the middle - who knows?

You made a point earlier about cycling the battery more than once a day, and this is a possibility I hadn't really considered and has had my head spinning all day. There's no reason why I couldn't charge the battery on E7 overnight, use the power (fairly quickly) for morning heating this time of year, then charge it with solar during the day for other uses, including the ASHP in the evening. That would potentially allow me to switch off the storage heaters earlier in the year, which are fairly inefficient at the moment. They don't cope well with cold nights and warm days and often over-heat the house. Not a huge deal because they do this using off-peak electricity, but a more controllable system with potential for some savings. Haven't worked it through yet, but mayber potential for another £20 or £30 per year savings doing this. Will crystallise my thoughts, try it and post back.

(PowerVault installation survey done today - installation due Weds - Thurs onwards I'm rich, Rich, RICH......)

Thanks, Mike

Zarch

1961Nick wrote: »

There's so much data that you'd need a username starting with "Z" to understand it all.;)

http://home.solarman.cn/login.html

It's free to register & it'll give you a good idea of what's available.

Sadly as I don't have a sofar inverter / pylontech battery combo I'm not sure what i'd see on there.

If you (or anyone else with the pylontech solution) could spare some time to show the basic charts / stats shown it would be appreciated.

1961Nick

Zarch wrote: »

Sadly as I don't have a sofar inverter / pylontech battery combo I'm not sure what i'd see on there.

If you (or anyone else with the pylontech solution) could spare some time to show the basic charts / stats shown it would be appreciated.

Never added an image before. Let's see if this works.

This is the front page that gives an overview of what's happening...



Edit: It didn't work.....any suggestions?

legoman62

1961Nick wrote: »

Never added an image before. Let's see if this works.

This is the front page that gives an overview of what's happening...



Edit: It didn't work.....any suggestions?

Upload it to something like Photobucket and send from there;)

1961Nick

legoman62 wrote: »

Upload it to something like Photobucket and send from there;)

Let's see if photobucket works...



Edit: Also failed

Why is this so difficult?



Success!

1961Nick

Here's the battery inverter..

1961Nick

The solar inverter..

1961Nick

The only slight problem I have is that the 'Real Time Generation' (post 848) is the sum of the generation being recorded by both inverters.

The data loggers are a couple of minutes out of sync, but generally the reading is double the actual production.

I've not managed to work out a cure yet other than by deleting the solar inverter from Solarman. It's no biggy because I only use that page for real time battery & consumption info rather than spreadsheets.