@robl Cheers for the screens dump - really useful. Battery charged fine overnight.

Raises some questions, Your shutdown, low and restart are 0%, 1% 2% - How did you come up with these numbers?

Your SOC is 1% - wow - Does you battery go that low and do you feel comfortable with 89%DOD?

@AdrianMc How is your charging going? My battery charged to 95% linearly, then really slowed down the rate, likely BMS, and only got to 97% in 7 hours. Is yours the same?

Likely setup 95%~15% for tonight - 80%DOD

My BMS seems fine , it charged to 100% from the solar few days ago. It seems to take all the charge that is given to it. 

@ggw While I’ve set it to work down to 1%, it’s an extremely rare occurance.  Most of the time it cycles 90% to 50%.  While I appreciate the degradation is higher if you let it drop low, LiFePo4 has such a long life, I’m not anticipating a problem with this.  This seems to me a more sensible approach than buying more batteries now and keeping DOD for sure lower - in the future they will be even cheaper.

Likely in a year or so it will be even less likely, as I expect we’ll have more PV, while still a similar use of elec.

@misterb - have been following your advice.

So I had couple of electricians came over the weekend and  confused me now. I have a meter cupboard outside my front door and consumer unit inside the house under stairs. Connection for the EV charger is taken from outside meter cupboard. 

I want to put the new Fogstar 15.5KW in the loft and there are cables already from consumer unit under the staircase to loft for the Solar with Solis inverter. The new hybrid inverter would also go in the loft. 

One of the electrician was saying he would need to run a ethernet cable for CT from meter cabinet outside to the loft  and another was saying it should be okay from consumer unit under the staircase to the loft. Not sure what's need to be done - any advice? Is there any possibility of using wireless CT, if so which please or is there any other alternative?

@ziaulh

Running an ethernet cable to your loft is well within the skill set of most people who have the mobility etc to do so. its just like a BT phone cable, which could also prob be used. basically for the CT clamp to connect, it needs two wires, not the eight wires in an ethernet cable. There is very little power going through the cable itself. 

are you going to change your inverter or keep both? just make sure the cable size is sufficient for the new inverter. your electrician will be able to advise you on the required size. My inverter in the loft, installed under FiT, is only fed by 2.5mm cable ... my sunsynk in the outside utility was over 'specced' at 6mm just in case i ever go for a bigger inverter. The cost of installing a higher rated cable for future proofing is no higher, though of course the cable will be dearer.

please note though the my 'advice' is based on a user and not an installer, electrician etc. 

if you have the option, you could use 4 or 6mm ultra cable from Doncaster cables, which has CT cables within its core. If you are able to do so, you could run this up the outside of your house into the loft yourself ..... most electricians ive ever worked alongside or i have employed to do work for me, hate running cables etc and they might be happy for you to run your own (and you would save some money which is always a plus point) 

getting a ready assembled battery into the loft might be a tad difficult, but as i dont know your circumstances it might be very easy !!

if you look back at a previous post, you will see that my electrician swapped out the consumer unit feeding my sunsynk with a bigger one, that now also includes the feed to to the EV charger. You can also get external consumer units, specifically for EV chargers, perhaps that might be an option, so it can be mounted externally next to your incoming mains meter box and then run the cables up the external wall into the loft? 

@ziaulh  Do you have the battery yet?  It's 145KG does not breakdown to smaller parts . It's heavy battery. 

Just make sure you can get it in the loft.

@adrianmc

No not yet. I understand the lead time is May at the moment. I believe the hatch is big enough to lift it up with few people and then  wall mounted to the brick? 

Do you have the exact measurements of the unit please in inches including all heights and corners? There is a potential it can fit in at my outside cabinet but the space is tight and DNO has have put meter quite low from the ground. I will post some pics later today for admise. 

@misterb

Yes, I will change the current inverter to Hybrid 5.5kw if I can put the battery to loft. If not, I will use separate nverter just for battery. At the moment the cable that goes up is 4mm which I think is good for 5.5KW inverter?

Will the CT need to be from the main meter or from consumer unit is fine? 

Posted by: @adrianmc

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@ziaulh  Do you have the battery yet?  It's 145KG does not breakdown to smaller parts . It's heavy battery. 

Just make sure you can get it in the loft.

although it comes ready assembled, it can be broken down into parts ..... though of course whoever does it needs to know what they're doing.

if it is difficult to get into the loft, perhaps a rack mounted system that breaks down into smaller components might work better .... or even the Seplos build yourself options?

@misterb if you open it you may void your warranty. It's the weight two slender men. Installer may not even attempt put up in attic. The dimension are on the spec sheet Fogstar website

@adrianmc thanks but I was also offering a solution, ie a self build Seplos or a Fogstar battery rack, as for the warranty if the person dismantling and assembling it knew what they were doing, it wouldn't be an issue. If I was that concerned re actually having to enact the warranty, I wouldn't put it somewhere where I can't get it out from without enlisting the help of several people ...

@robl 

So... The Sunsynk is not a intuitive firmware. That's is putting it mildly. The exchange between it and the battery, appears to be getting worse.

Won't charge now beyond 93%

And I stop it in user timer @15%

But twice now it has starting charging the battery in the evening, when the rate is expensive. It is linked to grid charge and a minimum of 10% that can be set.

God the manual is horrible

@ggw I had a lot of trouble with the sunsynk originally(ok, I still do…).  New LiFePo4 battery, with the Seplos bms that talked with it, and yet I found the 0-100% doc just wasn’t right - it would charge to 100% and charge for loads more still!  Then run to 0%, and still have more to give:  I ended up running the system on AGM voltage mode, 55.2V top and 42V bottom across the 16 cells.  After running like this for a few months the sunsynk bms re-evaluated the cell Ah, and now it works well in Li mode.

I recommend running in AGM voltage mode for a while and letting it find the battery size.  Ours evaluated the batt as 425Ah - it was sold as 304Ah.  I assume the sunsynk has an inaccurate current shunt on the battery current measurement, hence the difficulty with this.

Good luck.