Brucey
Solar Wizard
I think a good reason to look for a bolted cell design versus welded if buying preassembled batteries, so one doesn't have to ship 100-300lb batteries back to seller for warranty work.
How non-linear is battery life?
- Thread starter wpns
- Start date
Daddy Tanuki
Solar Wizard
glad somebody likes the mathIn answering the title of the thread, it would not be linear at all.
Sorry, I do math so I can't help myself.
i don't have enough braincells left for that kind of heavy lifting.
Brucey
Solar Wizard
It's the yttrium doping off gassing from those 400Ah cells Daddy, poisoning the mind. As I've said before, I will take the risk and take them off your hands....for the familyglad somebody likes the math
Daddy Tanuki
Solar Wizard
yeah I bet you would! this summer will be the summer of home underfloor hydronic heater build. have to add another 2kw of panels first though.It's the yttrium doping off gassing from those 400Ah cells Daddy, poisoning the mind. As I've said before, I will take the risk and take them off your hands....for the family
Daddy Tanuki
Solar Wizard
you know whats really sad? i keep eyeballing the next jump up for some reason...the 700 amp hour versionsIt's the yttrium doping off gassing from those 400Ah cells Daddy, poisoning the mind. As I've said before, I will take the risk and take them off your hands....for the family
Brucey
Solar Wizard
Let's face it we won't be satisfied till we get those monster 1000Ah cells.you know whats really sad? i keep eyeballing the next jump up for some reason...the 700 amp hour versions
I'll prob have to "settle" for LF560 cells with actual capacity in the 600s.... If they ever release to us end users.
Brucey
Solar Wizard
This is my first real year with solar and I'm surprised at what 3kWp can do as we enter spring/summer. Def need more battery to fully capture what's possible on my end.
Daddy Tanuki
Solar Wizard
I have been running with 5.6kw of panels but have another 2kw that i have not installed. for power in my 900 sqft cabin it has been more than adequate. that includes running my shop while there. Currently i cannot get the system to go below 85~90 % without purposely shutting off the SCC's.
That has been since i hooked up the new winston cells. i am fully charge even on bad days by 1100-1200 so my thought is turn the water boiler on at like 1000 and let it rip until the packs deplete to 50% and shut it down using the dry contacts from my magnum control panel based off of the shunts capacity reading.
Daddy Tanuki
Solar Wizard
those should be some real kick ass cells when they bring them out. it does make it easier not needing to parallel cells to get capacity. having multiple banks of large cells allows you to shut down a pack for maintenance or whatnot without shutting your house down.
Brucey
Solar Wizard
By the time they come out reportedly in Q4 this year I should be up to around 30kWh of assorted batteries, but have two jk BMS and ready for two big boy lf560 based batteries should end up being over 30kWh each depending what actual tested capacity ends up being.
Daddy Tanuki
Solar Wizard
Going full victron right? that takes some of the mental strain out of it for sure. how many kW inverter you planning on?
Brucey
Solar Wizard
Yeah full blue except the batteries. Looking at a Quattro 5 or 10 kVA. Youngest son has some decent 120V loads like air compressor etc he's putting in a metal building/workshop in the backyard, plan is to run from the inverter in the house about 100 yards out to there, give him about 50-100A of 120V and also power house loads except the AC (240v). Then add a second inverter for 240V capability and that should suffice for house and workshop. Hot water, stove/oven, dryer and forced air furnace are all propane though I heat the house with two portable oil filled radiators (they can maintain the temps at 70 unless outside dips below 20f but if house was 30F to start would need kerosene heater etc). I'm guessing 5kVA would be fine but not a huge difference in dollars to step up to the 10k.
Daddy Tanuki
Solar Wizard
if the price is not crazy go bigger... your needs will expand with time. currenlty I am powering everything off of one magnum 4448 PAE so 4400 watts at 240 split phase. I am getting ready to parallel my spare so I can get 8k+ originally did not need that much but as I play around....
wpns
Solar Joules are catch and release
I am dreading the 300 pound batteries, the 600 pound batteries better be self propelled and self lifting.
Typically you get roughly same or somewhat higher amount of total amp-hours with shallower discharges as long as you avoid the extremes of the voltage range.
So you can get 8000 100% DOD cycles, 16000 50% DOD cycles or 32000 25% DOD cycles.
But you won't get 80 000 10% cycles in the upper range ie 90% to 100% SOC
Temperature-wise avoid anything over 25Cel especially at high SOC. If operated below 15Cel it is better to limit the charging rate to lower than specified value.
Calendar-aging related problems/reactions are typically slower at lower temperatures so it is possible that for less frequently cycled battery pack the optimum temperature would be somewhere 10-15 Cel.
Just out of curiosity, what is your bulk/absorption voltage and absorption time?
Do you have float and if so what voltage and approximate time at that level?
Well if one were in Major League Baseball , with those #s’ they would be batting .900 in their whole career .
They would be the greatest player of all time…by farrrrrrrr….
They would be filthy rich too….
But since we’re not talking about baseball I say 10% failure on new gear is a tat high if one is buying good stuff….But,
It only takes a bad break or two to skew the numbers downward …
I have had no failures of new solar gear…UNTILL , I bought 16 new name brand solar panels about 2 years ago ..
8 of them had defective MC4 conectors and when hooking them up last year they crumbled in my hand like soda crackers ….fell to pieces….I cut off all 32 plugs and rigged a better connection and they work great since then…
Thus far in Solar I had Zero failures …then in one purchase I had 8 … that’s unreal…that skews my overall % of failure big time.
Sometimes bad luck just happens …not sure you can do anything about it…
You may go forward and never have another unlucky break…
Ya buy good and hope for the best…that’s all I know to do…
Good luck from here out..
J.
Warpspeed
Solar Wizard
These are lithium cells, not lead acid.
I charge to 3.45 volts, then hold at 3.45 volts until the sun goes down.
While its at 3.45v a fairly potent (home brew) top balancer kicks in.
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Warpspeed
Solar Wizard
Yup.
Its kind of like that.
It went for a year with no failures. At the end of two years I had two failures total, that was a bit of a worry.
At the end of three years, a third failure. So at that point I resigned myself to losing one cell per year.
Thirty years, thirty cells, with an average life of fifteen years.
Fifteen years x 365 = 5,475 cycles average.
However, its now 6.5 years with still three failures. At that rate it will take 58.5 more years for the other 27 to fail.
By then I will be 140 years old.
Daddy Tanuki
Solar Wizard
long before that one of those ugly azz spiders
you got down there will simply eat your ass whole... so nothing to worry about. Similar threads
