Yeah! Not getting the time to post and keep up at moment too busy with other things. You made an excellent choice but check out the LTO Lithium Titanium batteries on Bimble Solar. Early days, no info yet on Hybrid GTI compatibility or which BMS they are using but if you have the dosh it looks like the way to go.
Solis 3kW AC coupled Inverter & Fogstar 5.12kWh Rack Battery ?
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1 cycle a day gives that battery a theortical life of 82 years
. I suspect something would fall apart before then, but you could leave those in your will or the grandchildren .If you discharged / charged multiple times a day, I would say it's worth considering, but at £2k + VAT when I can get a battery 3 times bigger for simialr money, it's hard to justify the cost. Hopefully this battery tech will drop in price soon with a bit of mass production.
One of the things that interest me is how long batteries will last in reality, I'm not hearing of failures yet, but it will be interesting to see if they do make it to the full 6000 cycles promised.
I agree. Think about the tech we have had at home, every few years it changes and we buy something new so who is to say that the same thing will not apply to battery tech. A Japanese engineer invented the lithium battery as shown on NHK Top Inventions, would ear buds be possible without his pioneering work?
johnb2713
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£1000 per kWh, you must be having a laugh or have more money than sense, Jesus that’s expensive.
Tweet! I bet @ElonMusk uses them?
works at -30C though. Being able to install batteries externally would be a great benefit. Inverters (most) can be mounted externally, so you could install all the gear outdoors. But at £1k per kWh, you can buy a lot of sheds and greenhouse heaters
One of things I've seen over the years, is great ideas / new tech in regards to solar come and go, mostly down to cost. If an idea doesn't catch on, it never achieves the economies of scale that go with mass manufacturing, and the price fails to fall enough to make it economic.
johnb2713
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He maybe does but then again he also launches the biggest rockets in the world too, have you got a space mission imminent from your back garden or own a car factory?
johnb2713
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Such useful feature being able to operate at -30…….works at -30C though. Being able to install batteries externally would be a great benefit. Inverters (most) can be mounted externally, so you could install all the gear outdoors. But at £1k per kWh, you can buy a lot of sheds and greenhouse heaters
Yep, agreed.
A bit excessive for the UK, but would suggest our normal winter temps at around -5/10C would have a very minor affect on the battery performance. Unlike current batteries.
Fogstar rack batteries are just a little cheaper. They say "Our racks are built for the UK Climate. They heat themselves when a temperature of <5°c is detected, enabling the user to charge our racks in temperatures of -20C." Ideal for the cold garage in UK winter.
They say "Our racks are built for the UK Climate. They heat themselves when a temperature of <5°c is detected, enabling the user to charge our racks in temperatures of -20C." Ideal for the cold garage in UK winter.I think I'll stick with my 14.5kWh battery for not much more money.
I don't think there's any point paying way over the odds (unless you live somewhere very cold), battery tech is advancing all the time. CATL has a battery with 500Wh/kg, more that twice the energy of a Tesla Model B battery by weight. I'm sure there will be better options when my cells give up in 10 to 15 years or more time.
https://newatlas.com/energy/catl-500-wh-kg-condensed-battery/
I don't think there's any point paying way over the odds (unless you live somewhere very cold), battery tech is advancing all the time. CATL has a battery with 500Wh/kg, more that twice the energy of a Tesla Model B battery by weight. I'm sure there will be better options when my cells give up in 10 to 15 years or more time.
https://newatlas.com/energy/catl-500-wh-kg-condensed-battery/
Are you able to create a YouTube video of your efforts as I feel sure they would be much appreciated by a wider audience? The issue that concerns me is cell balancing during the autumn/winter/spring months. As far as I am aware balancing only takes place when the battery is fully and then it needs time whilst full to equalize cells. How do you plan to accommodate this? Are you going to disconnect the battery and charge it separately from the grid?
I think perhaps Fogstar might if asked make a video of a typical install for potential customers to give an idea.
I don't yet have a cell balancing problem and I have really used and abused this battery.
Happiness is 48-55.2V I am told
Ooops.
The cells seem to balance themselves quite well, often when I check they are 1mV difference across 16 cells. Right now charging at 32A there is 6mV difference. Once it gets to 99% full the BMS slow charges to 100%
More battery abuse, If I have 3 Fogstar batteries correctly addressed and connected via the RS485 links and I strap them all in parallel & place the Inverter cables to top left and bottom right as you should.
Can I then if need be turn off the middle battery BMS and breaker plus flick the address switch on battery 3 so its now seen as battery 2?
The total batteries resistance as seen by the inverter will still be balanced, just 1 battery less.
I'm thinking I can fill 3 batteries during summer months but in winter 2 will be enough so why not keep it as a reserve then and save the cycles.
Only 2 connected so far in pic.
Can I then if need be turn off the middle battery BMS and breaker plus flick the address switch on battery 3 so its now seen as battery 2?
The total batteries resistance as seen by the inverter will still be balanced, just 1 battery less.
I'm thinking I can fill 3 batteries during summer months but in winter 2 will be enough so why not keep it as a reserve then and save the cycles.
Only 2 connected so far in pic.
johnb2713
Well-known member
No point IMHO, the amount coming out of the batteries whether 2 or 3 are in circuit will be shared between them and thats what gets replaced when you charge. Probably better to keep the wear and tear equal.
bladerunnerpv
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Should there only be one black lead connected to middle battery, like on the red leads, or am I misunderstanding the daisy chain?
If you look at the inverter cables they are connected diagonally, this is so equal current is drawn from each battery, when the third battery is connected the negative inverter cable will be connected to that, and the positive stays on the first as it is.
johnb2713
Well-known member
Theyre not daisy chained, theyre in parallel. The outgoing leads are connected to opposite ends of the parallel leads to balance out the small amount of resistance in the leads so that the first battery in line doesnt take the lions share of the work during charging and discharging.
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