Solar PV battery options

dudley72

https://www.boards.ie/discussion/comment/117999987#Comment_117999987

GivEnergy, that’s my system

please note it’s a 8.x so along with my existing 2.x it brings it up to 10

Scoopsire

Has anyone used a GivEnergy inverter with a DIY or non GivEnergy battery?

Geeyfds53573

How are the battery builds going guys?

Thanks Garo for the list very interested in any issues ye face?

SouthWesterly

Are people who got a battery on the grant and then sold it installing it or just selling it without being installed?

DrPhilG

https://www.boards.ie/discussion/comment/118013710#Comment_118013710

Mine were installed for just under a year before I sold. Suited well though, I just disconnected the PylonTech and used the same isolator to connect the DIY.

SouthWesterly

https://www.boards.ie/discussion/comment/118013747#Comment_118013747

Thanks Phil

Another quick question. How difficult would it be to get panels on a roof and have the inverter in a shed outside. It's probably 20 meters from the fuse board.

Plan is to to put in a few extra panels on the roof with an installer and do do a DIY on the ground behind the shed and run the cables to the inverter in the shed

DrPhilG

Not a problem. I have panels on the house and the garage, connected by cable run to the inverter in the house.

garo

https://www.boards.ie/discussion/comment/118013268#Comment_118013268

All the equipment has arrived. The cells were all 3.32-3.34 V when I opened them. I've done a passive balancing job on them. Need to extend the DMS wires and crimp them next. The ring terminals on the BMS wires are 6mm while the battery bolts are 8mm. Will update with pics this weekend.

Geeyfds53573

https://www.boards.ie/discussion/comment/118015039#Comment_118015039

Thanks Garo.

SD_DRACULA

https://www.boards.ie/discussion/comment/118015039#Comment_118015039

Yeah give as much detail as possible, I have a feeling will eventually follow in your footsteps. You running the seplos bms?

reklamos

Definitely keep us in the loop. I am waiting for batteries to drop and will pull the plug myself also.

garo

Yep using seplos BMS. I think the OP already posted lots about his build from page 22 onwards. But sure I will share my experiences too.I've posted a couple of videos in the Seplos BMS thread which might be useful.

SouthWesterly

https://www.boards.ie/discussion/comment/118014855#Comment_118014855

Thanks. I saw your set up elsewhere. Impressive.

I just had a spark in looking at a job for me and was talking. He suggested not putting any panels on the roof (East) but to just put panels on the ground facing south and he could connect them all up.

He said not to bother with a hybrid inverter. Just go standard. I assume if I got a big inverter I'd have to limit both to 6kw(in total) for export

graememk

https://www.boards.ie/discussion/comment/118015794#Comment_118015794

You would only need to limit one of the inverters as a ct would be used and it would "see" the export and would adjust accordingly.

Do the sums on a hybrid, and if you want a battery or not. How "outside" is the inside of the shed?

SouthWesterly

https://www.boards.ie/discussion/comment/118016037#Comment_118016037

Shed is about 20m from house. It's a room at the end of a long shed if that makes sense so not much of a gap and fuse board is just inside the back door. In some ways a hybrid future proofs me but I assume their cost will come down in time

graememk

https://www.boards.ie/discussion/comment/118016067#Comment_118016067

Are you planning on wiring it into the fuseboard in the shed or just bringing a cable back to the house.

Would only get a hybrid if your putting a battery in now.

SouthWesterly

https://www.boards.ie/discussion/comment/118016278#Comment_118016278

Planning on bringing the wire into the fuse box in the house. Though it might be worth getting a sub box in the shed.

Not sure on battery but could be 6 months after the panels and it would seem a waste of money not to.

I assume I could put 2 stings of panels into the inverter. I've a field at the back for the panels but don't want to go too far back.

graememk

Most inverters are dual string. If your sure your putting a battery a hybrid is the easier option, also will be able to charge and discharge at 5kw if you get the solis.

I've my panels about 50m away from my inverter. Going on a 5core 6mm² SWA cable.

SouthWesterly

https://www.boards.ie/discussion/comment/118016368#Comment_118016368

How does the Sofar 3000 rate against the solis?

graememk

https://www.boards.ie/discussion/comment/118016659#Comment_118016659

The me3000sp is storage only, max output is 3kw. Although that is separate from the PV output.

The new solis hybrids can do 5kw.

Drawback of a hybrid, the max it can output is 6kw(5 on batteries alone). Even if the sun is splitting the sky and the batteries full. - the batteries need to support 100amp discharge though.

unkel

ME3000SP is rated for 3kW but it can actually output 4kW* and if you have a 6kW PV inverter (and sufficient solar panels obviously), your total output can be 10kW without drawing anything from the grid 😁

*with a full battery, that is 16 cells LiFePo4 at 3.65V fully charged, the inverter can be set to discharge at 70A, 16*3.65*70=4kW

jkforde

Economics \ payback of adding another 2.4kWh Pylontech to already existing 2.4kWh Pylontech (<6mths 6.7kwp Solar w\ Solis 5G 5kW)

Cost of buying & installing another US2000 2.4kWh: 1150 (incl. 23% VAT) + installation = ~€1500 (e.g. solartricity)

€€€ of lifetime discharged energy from US2000 battery (DOD 85%): 5000 (cycles) x 2.0 (kWh) x €0.25 (unit cost) = €2500 (trying to be pessimistic\conservative)

Saving from 5000 cycles of battery = €1000

I'd say I'm being unrealistically optimistic (or just plain wrong! :) ) as everyone says that batteries just don't pay...

unkel

Not if you spend €1500 on a 2.4kWh battery. I'm about to get 20kWh for similar money...

graememk

https://www.boards.ie/discussion/comment/118029638#Comment_118029638

Ooof 25c /kwh.. you need to change supplier! Most rates are around 17-20c, that's a fifth off your saving already.

5000 cycles, maybe 250 cycles/yr on solar, that's 20 years. -

if you do night rate charging, say on Energia's ev tariff, that's roughly 12 c saving /kwh taking losses into account.

How do the sums line up now?

jkforde

https://www.boards.ie/discussion/comment/118030068#Comment_118030068

fair play, all I can do is laugh at my own ignorance! 😁🤣😂

championc

https://www.boards.ie/discussion/comment/118029638#Comment_118029638

You may be right but if you fill it 250 days a year, that will be 20 years for 5000 cycles

garo

I'll have a two year old Pylontech going up for sale soon at a price less than half that 1500. Been kept in a garage so no temp extremes and with very conservative temp settings.

slave1

How's your build going? I haven't started mine yet, difficult to track down the Sofar 3000 and the Seplos BMS ordered kept resetting when powered off so back on a waiting list for fresh supply. In fairness I'm up to my neck with work/other DIY stuff so probably wouldn't have progress much anyhow

DrPhilG

Just realised I forgot to list my blunder in here...

When I moved my batteries due to the shelving unit crapping itself, I had to disconnect the bms cabling when shifting.

Due to being a stubborn git and starting the move at about midnight, I blame the tiredness in the wee hours for the fact that connected up the BMS cables to the wrong cells. Mixed up the B- and cell 3.

Anyway the long and short is that I fried a couple of the transistors in the BMS. The result was that although the battery still worked, cell 1 was constantly reading low and cell 3 was constantly reading high. Both by about 0.2 of an error.

Spoke to the ZEVA guy and he told me what to change, got the transistors online, dirt cheap. Friend of mine swapped them out the other day and were back up and running perfectly.

SouthWesterly

https://www.boards.ie/discussion/comment/118035529#Comment_118035529

I wish I knew what you were talking about 😱