Adding additional battery to Tesla Powerwall setup

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NikoV6
Posts: 217
Joined: Thu Aug 11, 2022 6:42 am

Adding additional battery to Tesla Powerwall setup

#1

Post by NikoV6 »

Being quoted £9K for an additional Powerwall which is unacceptable!

So, looking at other options (if there are any that will play nice with Tesla!)

Estimate is we need an additional 10 - 15kWh to see us stay on overnight rate for all of the year.

We have 10kW solar split between three strings. Thought was to split one off to feed another battery?

https://www.itstechnologies.shop/collec ... octopus-go

I cant make out if this needs an inverter too?

Other options please? :mrgreen:
14Kw Mitsubishi Ecodan ASHP
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Fintray
Posts: 1303
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Location: Aberdeenshire

Re: Adding additional battery to Tesla Powerwall setup

#2

Post by Fintray »

NikoV6 wrote: Wed Oct 25, 2023 8:10 am Being quoted £9K for an additional Powerwall which is unacceptable!

So, looking at other options (if there are any that will play nice with Tesla!)

Estimate is we need an additional 10 - 15kWh to see us stay on overnight rate for all of the year.

We have 10kW solar split between three strings. Thought was to split one off to feed another battery?

https://www.itstechnologies.shop/collec ... octopus-go

I cant make out if this needs an inverter too?

Other options please? :mrgreen:
From the ITS page - "Up to 5 batteries can be used with each AC charger/hybrid inverter, multiple charger/inverters can be installed."

I'm also looking to add additional battery storage but am going down the Victron inverter and DIY battery pack route.
3.87kWp PV
10.24kWp PV SolarEdge system
Tesla Powerwall 2
100 x 47mm Navitron tubes (still being installed!) Now likely to be removed for more PV.
MK2 PV router DHW diverter
Morso 5kW WBS
Vaillant AroTherm 10kW ASHP
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NikoV6
Posts: 217
Joined: Thu Aug 11, 2022 6:42 am

Re: Adding additional battery to Tesla Powerwall setup

#3

Post by NikoV6 »

Fintray wrote: Wed Oct 25, 2023 9:01 am
NikoV6 wrote: Wed Oct 25, 2023 8:10 am Being quoted £9K for an additional Powerwall which is unacceptable!

So, looking at other options (if there are any that will play nice with Tesla!)

Estimate is we need an additional 10 - 15kWh to see us stay on overnight rate for all of the year.

We have 10kW solar split between three strings. Thought was to split one off to feed another battery?

https://www.itstechnologies.shop/collec ... octopus-go

I cant make out if this needs an inverter too?

Other options please? :mrgreen:
From the ITS page - "Up to 5 batteries can be used with each AC charger/hybrid inverter, multiple charger/inverters can be installed."

I'm also looking to add additional battery storage but am going down the Victron inverter and DIY battery pack route.
Sounds interesting, will you be detailing your build?
14Kw Mitsubishi Ecodan ASHP
22 x JA Solar 455W Mono Perc Half Cell Silvers
Solis 8.0Kw 5G Dual MPPT Inverter
13.5Kw Tesla Powerwall
Zappi 2 Charger
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Moxi
Posts: 1781
Joined: Sun Oct 31, 2021 3:46 pm

Re: Adding additional battery to Tesla Powerwall setup

#4

Post by Moxi »

Nikov,

Check the comments section for that link you posted, the price seems to have gone up quite a bit since last year, also IIRC there was some discussion about this same item as sold by Octopus whereby you appear to pay and hand over control to them - hence the battery system appears to not be as accessible and home user friendly as some of the other market options where you can change parameters and settings to suit your needs and with some effort in some cases download your data without having to export to the cloud first - thats if I have understood the other threads on the forum and believe me the ICA side of batteries and inverters is an uphill struggle for me most of the time :oops:

Moxi
NikoV6
Posts: 217
Joined: Thu Aug 11, 2022 6:42 am

Re: Adding additional battery to Tesla Powerwall setup

#5

Post by NikoV6 »

Moxi wrote: Wed Oct 25, 2023 12:05 pm Nikov,

Check the comments section for that link you posted, the price seems to have gone up quite a bit since last year, also IIRC there was some discussion about this same item as sold by Octopus whereby you appear to pay and hand over control to them - hence the battery system appears to not be as accessible and home user friendly as some of the other market options where you can change parameters and settings to suit your needs and with some effort in some cases download your data without having to export to the cloud first - thats if I have understood the other threads on the forum and believe me the ICA side of batteries and inverters is an uphill struggle for me most of the time :oops:

Moxi
Thanks, will do!

I think my confusion came from it not explicitly stating it needed an inverter on that page. They mention plug and play functionality, for the uninformed it would have been nice to see "Also requires xxxx Inverter to function" :D
14Kw Mitsubishi Ecodan ASHP
22 x JA Solar 455W Mono Perc Half Cell Silvers
Solis 8.0Kw 5G Dual MPPT Inverter
13.5Kw Tesla Powerwall
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Fintray
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Re: Adding additional battery to Tesla Powerwall setup

#6

Post by Fintray »

NikoV6 wrote: Wed Oct 25, 2023 10:45 am
Fintray wrote: Wed Oct 25, 2023 9:01 am
NikoV6 wrote: Wed Oct 25, 2023 8:10 am Being quoted £9K for an additional Powerwall which is unacceptable!

So, looking at other options (if there are any that will play nice with Tesla!)

Estimate is we need an additional 10 - 15kWh to see us stay on overnight rate for all of the year.

We have 10kW solar split between three strings. Thought was to split one off to feed another battery?

https://www.itstechnologies.shop/collec ... octopus-go

I cant make out if this needs an inverter too?

Other options please? :mrgreen:
From the ITS page - "Up to 5 batteries can be used with each AC charger/hybrid inverter, multiple charger/inverters can be installed."

I'm also looking to add additional battery storage but am going down the Victron inverter and DIY battery pack route.
Sounds interesting, will you be detailing your build?
I'll try my best to give as much detail as I can.
3.87kWp PV
10.24kWp PV SolarEdge system
Tesla Powerwall 2
100 x 47mm Navitron tubes (still being installed!) Now likely to be removed for more PV.
MK2 PV router DHW diverter
Morso 5kW WBS
Vaillant AroTherm 10kW ASHP
Nissan Leaf
richbee
Posts: 506
Joined: Tue Apr 19, 2022 3:39 pm
Location: Northumberland

Re: Adding additional battery to Tesla Powerwall setup

#7

Post by richbee »

Fintray wrote: Wed Oct 25, 2023 9:01 am
NikoV6 wrote: Wed Oct 25, 2023 8:10 am Being quoted £9K for an additional Powerwall which is unacceptable!

So, looking at other options (if there are any that will play nice with Tesla!)

Estimate is we need an additional 10 - 15kWh to see us stay on overnight rate for all of the year.

We have 10kW solar split between three strings. Thought was to split one off to feed another battery?

https://www.itstechnologies.shop/collec ... octopus-go

I cant make out if this needs an inverter too?

Other options please? :mrgreen:
From the ITS page - "Up to 5 batteries can be used with each AC charger/hybrid inverter, multiple charger/inverters can be installed."

I'm also looking to add additional battery storage but am going down the Victron inverter and DIY battery pack route.
How do you make sure the inverters play nicely together (if not the same type and connected in parallel), in terms of charging / discharging batteries - you don't want 1 battery discharging to charge the other one.
I guess some of it will come down to the placement of the CT coils & accuracy - plus settings?
Solar PV since July '22:
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Fintray
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Location: Aberdeenshire

Re: Adding additional battery to Tesla Powerwall setup

#8

Post by Fintray »

richbee wrote: Wed Oct 25, 2023 3:00 pm
How do you make sure the inverters play nicely together (if not the same type and connected in parallel), in terms of charging / discharging batteries - you don't want 1 battery discharging to charge the other one.
I guess some of it will come down to the placement of the CT coils & accuracy - plus settings?
I think it will be a bit of experimentation to see how they work together, or don't as the case may be!
3.87kWp PV
10.24kWp PV SolarEdge system
Tesla Powerwall 2
100 x 47mm Navitron tubes (still being installed!) Now likely to be removed for more PV.
MK2 PV router DHW diverter
Morso 5kW WBS
Vaillant AroTherm 10kW ASHP
Nissan Leaf
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