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Forum Index : Electronics : Wiseguy New Inverter Build Nano R6
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| rogerdw Guru  Joined: 22/10/2019 Location: AustraliaPosts: 949 |
Congratulations Mike, a very tidy looking installation. Just a little bit neater than my good old forklift battery and still uncovered Warpverter and MPPT's.  Did they add more panels too or just hook up what you already had? How many kW? Cheers, Roger |
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wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1235 |
Thanks Roger, we had 13.5kW of panels on the roof which used to feed a 10KW 3 phase Fronius. They were going to AC couple the existing Fronius, meaning even if we were able to generate 13.5kW it would have only charged the batteries at 10kW. It made more sense to DC couple the panels to the inverter and just remove the Fronius. I looked on Marketplace and there are at least 6+ 10kW Fronius inverters starting from $100, most refer to a recent battery upgrade. I don't think I will even bother advertising mine, might do a teardown to see what goodies are inside - might be a good source of ringcores suitable for stripping and rewinding as inverter chokes. Considering they were worth ~ $3K just a few years ago I sense there will be an avalanche of inverters about to flood the "used" market thanks to the recent battery subsidy. If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike |
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| -dex- Senior Member  Joined: 11/01/2024 Location: PolandPosts: 102 |
Hi, We have a saying: "a shoesmaker without shoes" – this is in the context of your energy storage system, Mike  My first thought was: what's so crazy about installing an LFP outdoors? But I looked at the winters in your latitude and realized there's no need to worry. In my location, winter temperatures often drop well below 0°C and stay there for many days. Do you know what type of cell your battery storage uses? Cylindrical cells, such as the EVE C40, are common in these products. BTW. I haven't been here in a while; my thread should be dusted off and updated  |
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| wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1235 |
Hi Dex, good to hear from you again. How's that inverter running - the warranty period has expired now  Today was a warm day in South Australia it reached ~37 Deg Celsius in the afternoon - I won't need to worry about cold batteries for a while yet. The batteries are Lithium Iron Phosphate types, I read somewhere there are supposedly 9 battery cells each 280AH. I think they may well be EVE LF280Ks ? However, the pamphlet eludes to "low voltage" but also lists the voltage range in the battery specs as 600 - 900V which is at odds with low voltage. The max power you can draw is 0.5C or 4kW for the 8kWh module. Sig Battery Info Sheet: Sig Battery Info.pdf Another information document: Advanced battery technology SigenStor uses LFP (lithium-iron-phosphate) cells with a capacity of 280 Ah, offering several advantages over conventional battery solutions: Higher reliability and safety: The 280 Ah cells have a lower voltage of 32.85 volts, significantly reducing safety risks compared to conventional solutions that use 100 Ah or smaller cells, which can raise the battery voltage above 91 volts. Extended lifespan: The 280 Ah cells also have a longer lifespan, so the energy storage system remains reliable for many years. So I can draw the following conclusion I think; Perhaps the Battery voltage is 33V nominal but there is a boost converter in each battery module that provides the high voltage rail used by the top inverter. Otherwise for its full rated 24kW output the 33V batteries each provide a total of ~ 750A at the rated output which divided between six modules means each battery is providing ~ 125A and I'm confident there are not 750A busbars passing the energy up to the top inverter. Second observation the inverter is too light to be a LV toroidal type, so I conclude it must use HF HV SPWM switching. Edited 2025-12-18 22:54 by wiseguy If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike |
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| analog8484 Senior Member Joined: 11/11/2021 Location: United StatesPosts: 179 |
Interesting to see Sigen. What's the warranty? They are still rare in the US with unproven support track record. Don't know if you have an EV but Sigen offers a V2X module that looks interesting. |
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| wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1235 |
No we don't own an electric vehicle yet but in a few years it is on the cards. Yes I was aware of Sig's EV support and modules. I am posting the SIG PDF documents here that I have to hand as they will answer most queries. I am not on a finders fee or receiving commissions etc for Sig referrals...... After doing some research online, mainly from the UK, many of the premium installers there swear by SIG products and after seeing their installs and their efficiency & perceived reliability, I decided to bite the bullet. Initially I was only going to install 16kWh of storage but when the Government started the home battery subsidy scheme the cost of each 8kWh module was only around $1K9 extra so I decided to up the reserve to 48kWh and upgrade the inverter to 24kW 3 phase so on the nights where it doesn't get below 28+ degrees, then we can run the ducted air all night. The other advantage is that in winter where we typically only use ~ 6kWH per day we could have a week of essentially no sun and no Mains power and still be self reliant. Last night we did just that and this morning we still had 49% battery capacity remaining & no power consumption from the grid despite running the Air most of yesterday and the batteries started at sunrise yesterday with 0% charge remaining however we only returned ~ 3.5kWh to the grid around 4.00pm yesterday instead of ~ the usual 50-60kWh for a typical day at this time of year). Now we are starting at ~%50 storage capacity so I estimate we will export ~ 30+kWh today. That will help pay for the "supply" connection which even with no power drawn is $2.19 per day, whilst receiving a whole 0.09c per kWh returned but being charged 68.92c per kWh consumed at the peak rates (where we usually had to consume energy outside of solar generation). Thanks Engie (our provider) what a great deal..... Sig Warranty: Warranty-Document-Sigenergy.pdf Sig Spec sheet: Spec-Sheet-Sigenergy.pdf It does not state implicitly the battery warranty but it implies 10 years which is what sales said (yeah I know) - I will ask for further clarification. Edited 2025-12-19 08:38 by wiseguy If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike |
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