How did you pick your battery?

[Gill]

In the process of getting PV quotes with and without battery. 

 

The installer today asked me to come back with some batteries that I think I'd be interested in. Trouble is I don't know what's good and what's not or what features I should be looking for. 🙄

 

I accept there no crystal ball so expect no ROI but in electric only property with no EV and eco 7 tarrif it will give us additional flexibility and allow us to use more of our generation. 

 

I would like at least 12 kWh battery and would prefer more winter we can go through 20 - 30 kWh on peak tarrif and charging some of that off peak will give additional offset against cost.

 

How did you go about comparing batteries? Any good resources to share that compare charge /discharge rate, multiple batteries vs single and other key features ? The standard 'top 10 home battery' compilations are useless and rarely include more than the powerwall for higher capacity options. 

 

Thanks 

[TonyT]

Plyontech 

[Thorfun]

I wanted something that could power the house in a power cut. Tesla Powerwalls had stupid lead times and so I went for a Luxpower Squirrel Pod with HanchuEss Greenlinx batteries   

the maximum 13A in a power cut is a little limiting but I’m planning to ask the sparky to wire lights and a coupling of emergency sockets to the EPS. 

 

but you’ll find that answer to your question depends on who you’re asking! If you read the threads in the battery forum you’ll get a good understanding of the sort of response you’ll get. 😉

[Gill]

Thanks - I'll take a look at all options as I'm very much at the learning the lingo phase. 

Indoor housing vs outdoor, large capacity vs stackable, extensibility, draw rates, grid /solar charge rates, AC vs DC.... What can of worms have I cracked open this time?😁

No wonder it's difficult when everyone has very different and specific requirements. 

 

[Gill]

On 10/05/2023 at 21:35, Thorfun said:

I went for a Luxpower Squirrel Pod with HanchuEss Greenlinx batteries   

 

@ThorfunThis is an interesting solution. I'm finding it rather difficult to compare batteries that meet my needs. Specifically in the winter months I want the option of a high draw rate as we'll be running some heating & cooking all on electric. 

 

If I understand the squirrel pods, these  replace the single inverter? If I went two pods and enough batteries to max the draw, I have ability to pull 7 kWh concurrently. For grid export am I correct in thinking that would cap at 7kW also? 

 

How you finding the system is working for you? Also curious if it would support different batteries or if its limited to greenlinx. I'm not seeing it documented the max number that can be chained - how many pods are you running? 

 

The alternative I think would be a single larger inverter and batteries with high draw rate which only seems to be available on pricier models but there's a trade off - having more kit is potentially more points of failure. Never easy working this stuff out.... 

 

 

[Dave Jones]

tesla.

[Thorfun]

12 minutes ago, Gill said:

 

@ThorfunThis is an interesting solution. I'm finding it rather difficult to compare batteries that meet my needs. Specifically in the winter months I want the option of a high draw rate as we'll be running some heating & cooking all on electric. 

 

If I understand the squirrel pods, these  replace the single inverter? If I went two pods and enough batteries to max the draw, I have ability to pull 7 kWh concurrently. For grid export am I correct in thinking that would cap at 7kW also? 

 

How you finding the system is working for you? Also curious if it would support different batteries or if its limited to greenlinx. I'm not seeing it documented the max number that can be chained - how many pods are you running? 

 

The alternative I think would be a single larger inverter and batteries with high draw rate which only seems to be available on pricier models but there's a trade off - having more kit is potentially more points of failure. Never easy working this stuff out.... 

 

 

I had to cut back on spending so I only bought a single SPOD and 2 x 3.2kWh Greenlinx batteries but I have it in mind to expand that when I have some extra money. having 2 x SPODs and enough batteries would give you 7kW discharge rate. the export is not capped nor dependent on the battery system. this image shows today where I was exporting 8kW to the grid after the car had finished charging.

 

 

I find the system pretty good to be honest. like I said, I'm a bit miffed that I can only have 13A max as an emergency backup supply but we have very few power cuts and if we do at least that'll be enough to keep the lights on.

 

afaik the SPOD isn't limited to Greenlinx batteries. I bought directly from Big Green Beard and they also offer other batteries but the Greenlinx ones are the ones they recommended to me.

 

I believe that max 2 x SPODs can be chained but a call to Infinity Innovations should clear that up for you. 

 

I had this data sheet sent to me which might help.

 

Squirrel Pod Information-1.pdf

 

[Gill]

32 minutes ago, Thorfun said:

the export is not capped nor dependent on the battery system

 

Cheers for the data sheet.

 

Nice stats - so your export always maxes out when you're not using. For your g99 was that based on your solar array max generation then instead of squirrel inverter? I did see they have a g99 datasheet so assumed like other inverters this was enforcing a limit. 

 

35 minutes ago, Thorfun said:

bit miffed that I can only have 13A max as an emergency backup

Does seem a bit odd. EPS not high on my requirements list. Would be a nice to have something but I can probably live with a extension cable in an emergency. 

 

38 minutes ago, Thorfun said:

max 2 x SPODs can be chained but a call to Infinity Innovations should clear that up for you

Less of an issue with export not being limited. I've sent over a query anyway - good to know capacity should some random requirement come down the line. 

 

One other question on placement - temperature wise I'm thinking wall mount / get a rack under the house (suspended floor). That will keep the squirrels cool in the summer but there is a risk in depth of winter thar the battery performance will take a hit. Any experience with temps /performance? 

 

Thanks 

 

[Thorfun]

36 minutes ago, Gill said:

Nice stats - so your export always maxes out when you're not using. For your g99 was that based on your solar array max generation then instead of squirrel inverter? I did see they have a g99 datasheet so assumed like other inverters this was enforcing a limit. 

honestly don't know. my installers did the G99 application and I've not worried about it all since then but I presume so as I have a 10.5kWp array with a 10kW inverter.

 

37 minutes ago, Gill said:

One other question on placement - temperature wise I'm thinking wall mount / get a rack under the house (suspended floor). That will keep the squirrels cool in the summer but there is a risk in depth of winter thar the battery performance will take a hit. Any experience with temps /performance? 

I started a whole thread on the subject of placement. 

 

 

in the end I put the inverter and batteries in the basement next to the CU.

happy reading. 😉 

[Gill]

8 minutes ago, Thorfun said:

I presume so as I have a 10.5kWp array with a 10kW inverter.

Ah. My mistake - I thought the squirrel was performing the same job as inverter. So it's squirrels and inverters required. If you don't mind me asking, what inverter did you go with? 

 

I'll have a read through that thread - I want to avoid attic (summer heat) and indoor space is limited so at a premium.

 

 

 

[Thorfun]

3 minutes ago, Gill said:

Ah. My mistake - I thought the squirrel was performing the same job as inverter. So it's squirrels and inverters required. If you don't mind me asking, what inverter did you go with? 

 

I'll have a read through that thread - I want to avoid attic (summer heat) and indoor space is limited so at a premium.

 

 

 

you can get hybrid battery inverters that will do the pv and battery but I'd already purchased the Solaredge inverter with the PV system. there are many on here, @Nickfromwales is one, who would recommend you go for a DC battery system especially if EPS is not required.  @pocster is also having fun with a Solaredge battery and Powerwall combined system. I believe he's thinking of a second SE battery so might be worth getting their opinions as well.

 

if the wait for the PW2 wasn't 18 months when I was looking to get a battery system installed I'd have simply gone with that. but it was and I didn't want to wait so went the route I did. 

 

but it's a much larger field of options and probably more joining the arena all the time, it's more than my little brain can cope with! 

[Pocster]

I have both Tesla and SE dc battery .

Tesla is an expensive option in comparison ( wasn’t many other choices when I first got it ) . It is very good imho for the money - not just capacity but construction and the software . SE battery more primitive I guess BUT doesn’t require any DNO Stuff . Together with lots of fiddling ( trial and error ) is pretty darn good with pw 

I think you need to accept the issues / limitations of dc over ac and how much control you want /need .

I ( because I’m sad ) alter my setup practically everyday to suit / get the best results for me . Also ( important for me ) SE and Tesla designed to be happy outside .

Edited May 14, 2023 by pocster

[MikeGrahamT21]

Tesla batteries use the less common Lithium NMC, majority of DC batteries use Lithium Ferrous Phosphate, each have their advantages, NMC is better in low temperatures hence why powerwalls are generally seen externally on marketing material. LFP is safer and generally more efficient at lower SOC.

 

from google

When it comes to safety, LFP batteries beat NMCs due to their stable lithium chemistry. Even at higher temperatures, the Lithium Iron Phosphate chemistry is more stable than Nickel Manganese Cobalt.

 

if it’s going inside I would rule Tesla out myself.

 

I’ve got an ac coupled setup with pylontech batteries, I’ve written a blog about my experiences so far, on the forum, I can link it if you can’t find it

[Pocster]

I used to worry about the SE battery because it has a fire extinguisher built in 🙄 . V2 now though doesn’t .

Personally I’d want any battery outside of the main house ( garage etc. Ok ) . But how many instances have there been of any domestic batteries like these of any brand / construction; over heating / exploding / destroying the universe ?

Edited May 14, 2023 by pocster

[Gill]

15 minutes ago, Thorfun said:

it's more than my little brain can cope with

Very much this. 

Im still waiting on two installers coming back with their recommend rig so maybe I'll get some additional ideas. The one national is very much pushing down the small setup /no g99 route. I've learned enough to know this isn't optimal for us. 

 

19 minutes ago, Thorfun said:

the wait for the PW2 wasn't 18 months when I was looking to get a battery system installed I'd have simply gone with that

I'll admit I was put off by price. Draw rate is better than most. The greenlinx do seem good value with the drawback of needing the squirrel to boost concurrent output. There doesn't seem to be many options when you want higher draw. 

 

25 minutes ago, pocster said:

think you need to accept the issues / limitations of dc over ac and how much control you want /need

I think I need to do more reading as I honestly haven't looked at DC vs AC setup. More homework. I naively thought go with as much solar as I can afford to max out winter generation and size a battery for a winter store of eco 7 night rate to help reduce heating. (I get the battery isn't a financial Roi necessarily but will complement solar and our living pattern).  Will over generate summer so export from panels and potentially battery could help payback. 

 

33 minutes ago, pocster said:

Also ( important for me ) SE and Tesla designed to be happy outside .

No performance degrade in the colder months? One installer was dead against outdoor battery install but I guess that could have been the battery they prefer to install - still waiting on those details. 

 

[Canski]

2 hours ago, Dave Jones said:

tesla.

why ?

[Pocster]

8 minutes ago, Gill said:

No performance degrade in the colder months? One installer was dead against outdoor battery install but I guess that could have been the battery they prefer to install - still waiting on those details. 

Tesla has its own heating / cooling so performs the same in all weathers . My SE in winter ( never had any problems in summer ) can struggle to fully charge if temperatures are too low . So in a *perfect* world I’d want a dc battery under cover and out of the weather . Not feasible for me .

Tesla can be a ‘set and forget ‘ option if you want musk’s algorithm to do its thing 😁

Edited May 14, 2023 by pocster
Not doughnuts

[Pocster]

I believe supply of all batteries and prices are more abundant now .

So it’s a better market to buy than perhaps 12 months ago . I got SE because wait time ( at the point of order ) for a PW was 18 months and DNO said no anyway . I still argue even now with DNO because I’m like that 😁

[Gill]

30 minutes ago, pocster said:

Tesla can be a ‘set and forget ‘ option if you want musk’s algorithm to do its thing 😁

The input from the other half which I've sanitised somewhat was 'I'd prefer if you didn't line the pockets of tesla'. That said, I do IT all day so it's not fun to spend the evening tweaking the tech. Can you turn off the mothership on the teslas? I'd read a while back about the. I intelligently deciding to charge ahead of potential storm that never happened. Can't be having my battery AI not comprehend I'd rather sit in the dark and be cold than consume peak rate electricity. 

 

35 minutes ago, pocster said:

. I still argue even now with DNO because I’m like that

I've not approached ours yet. That's tomorrows fun task. 

[Pocster]

9 hours ago, Gill said:

The input from the other half which I've sanitised somewhat was 'I'd prefer if you didn't line the pockets of tesla'. That said, I do IT all day so it's not fun to spend the evening tweaking the tech. Can you turn off the mothership on the teslas? I'd read a while back about the. I intelligently deciding to charge ahead of potential storm that never happened. Can't be having my battery AI not comprehend I'd rather sit in the dark and be cold than consume peak rate electricity. 

 

I've not approached ours yet. That's tomorrows fun task. 

You can influence it . E.g change price of buy / sell per kWh . I have had it where it didn’t charge at night and I’m stuffed the next day . The algorithm ( not really AI is it ! ) is not perfect . But if you accept it gets it wrong sometimes but is surprisingly right other times then you can just leave it . But I’m a fiddler .

SE is simpler ( though SE claim to be adding AI - I’m hoping I can disable that ) .

I’d certainly talk to your DNO - they can give you an indication of what you can have also ask them about various battery options .

[MikeGrahamT21]

Assuming you won't be on the FiT Rates, a hybrid inverter should be your go to, there is absolutely no point in going AC Coupled, due to the fact you will lose a lot of energy through inverter efficiencies.

 

You'd be going Solar PV (DC) > Inverter (DC to AC) > AC Coupled Inverter (AC to DC) > Battery (DC)

 

With hybrid you would be going Solar PV (DC) > Inverter (DC) > Battery (DC)

[Pocster]

I believe ( just as a note of interest ) pw 2+ has greater sustained output 5.8kwh and a PV inverter built in along with its ‘own’ inverter .

[Pocster]

1 hour ago, MikeGrahamT21 said:

Assuming you won't be on the FiT Rates, a hybrid inverter should be your go to, there is absolutely no point in going AC Coupled, due to the fact you will lose a lot of energy through inverter efficiencies.

 

You'd be going Solar PV (DC) > Inverter (DC to AC) > AC Coupled Inverter (AC to DC) > Battery (DC)

 

With hybrid you would be going Solar PV (DC) > Inverter (DC) > Battery (DC)

I have a question for you !

Why can’t my SE dc battery charge and discharge simultaneously ? . I assume it’s a SE design limitation ??? - just wondering . As that situation can cause me to loose some PV generation in certain circumstances- though I think I can reduce the chance of that now .

[MikeGrahamT21]

1 hour ago, pocster said:

I have a question for you !

Why can’t my SE dc battery charge and discharge simultaneously ? . I assume it’s a SE design limitation ??? - just wondering . As that situation can cause me to loose some PV generation in certain circumstances- though I think I can reduce the chance of that now .

 

How can you possibly charge and discharge something simultaneously? Thats just impossible. The power can only flow in one direction at any time. What scenarios lead to your loss of PV gen? Perhaps you are talking about the polling interval of the CT Clamp?

Edited May 15, 2023 by MikeGrahamT21

[Pocster]

13 minutes ago, MikeGrahamT21 said:

 

How can you possibly charge and discharge something simultaneously? Thats just impossible. The power can only flow in one direction at any time. What scenarios lead to your loss of PV gen? Perhaps you are talking about the polling interval of the CT Clamp?

Ok . It’s a rare example but has happened .

pw low . Se full . Discharge se into pw . If pv generation is greater than 3.68 pw will charge at 3.68 ( it’s max ) . Se can’t soak up extra over 3.68 as it’s discharging . ( or not if pv is 3.68 or greater - but it is in ‘discharge mode’ not ‘charge from solar ‘ ) .

Google tells me ‘ pass thru ‘ does exist and allows charge / discharge simultaneously 

 

Edited May 15, 2023 by pocster