Solid State Batteries

[biggkidd]

Papaof2 or anyone else heard anything about these yet? From what little info I've been able to find they will revolutionize power storage. Supposedly they will also be much cheaper to make than the current lines of batteries we all use. Safer too non flammable!

I for one can not wait to see this technology in person. We live off grid or rather on our own micro grid supplying our own power and if half of what I have read so far is true these will make a HUGE difference. Of course it will be several years before they work their way down to base consumers.

[papaof2]

Right now, the new favorite option seems to be LiFePO4 batteries with 3000 cycles to 80% capacity. The nest generation of lithium batteries is Lithium Titanate Oxide (LTO) which is theorectically capable of 20,000 charge/discharge cycles. 20,000 / 365.25 gives 54.75 years. Those batteries haven't been around that long, so no real expectations of how long they might last but 20 years seems reasonable - of course, some of the best lead-acid batteries (including AGM and gel) have proven 20 year life. The lithium batteries are smaller/lighter for similar capacity but don't have the years of proven service.

I always take "next great step in batteries" with a grain of salt from the "saltwater" batteries that were to revolutionize all types of things but the company folded in a couple of years because they couldn't deliver what they promised.

I see the unfortunate possibility of someone building large capacitor banks in "battery" cases and selling them as "solid state batteries". A few people are running their vehicles with a capacitor bank as the replacement for the original 12 volt starting battery but I wouldn't trust those - their voltage tapers off much more sharply than the voltage of a lead-acid battery (some vehicles have spillproof AGMs, some of those trunk-mounted to have more engine space and less heat damage to the battery).

My solar-charged backup system uses AGM (sealed lead-acid) batteries because 1) they have a long track record, 2) in standby service, batteries are kept at or near their maximum charge voltage and while that's the "float" voltage for lead-acid batteries, a lithium battery's best storage voltage is about half charge - higher voltages shorten the battery's life, 3) from experience, I can usually find nearly new AGM cells for half price or less and my (somewhat nit-picking) care for them gives me more than their estimated 5-7 year life (almost 9 years to 80% of original capacity on the first set).

[biggkidd]

Yeah I'm running absolyte 2 volt cells in my 48 volt system. For a total of 652 amp hours @ 48v nominal. I don't have nearly enough storage capacity. These Virgen lead AGM's I got used came out of a hospital operating room backup power system. Thankfully I do have plenty of panels. So we keep things like washing clothes or other high energy items for sunny days.

[papaof2]

The limited solar panels I have outside are for keeping the backup battery bank charged. If we were without power for longer than I have fuel (currently about two weeks' worth of treated fuel - then we tap the vehicles), I have another 1000 watts of solar panels and the controllers to handle that. We'd be slightly better than "cabin in the woods", as we would have a fridge and - if AT&T has backup power, of which no sign during our snow-caused outage three years ago (our power out 12 hours, U-verse out 30 hours) - possibly internet and TV on a limited basis. We do have a rechargeable 7" HDTV so we could watch any local stations that might have power. If we dropped back to just the counter height fridge in the basement, 600 watts of solar would keep us going with limited LED lighting, charging tablets and laptops for reading or writing and charging cell phones if there is service (400 watts would handle daily power but we don't have daily sunshine). There's a solar + crank AM/FM/shortwave/weather radio that lives in a South-facing window so we always have a radio available. BougeRV has a 30 quart compressor-driven fridge/freezer that's under $250 and requires about 120WH/day. That would be a lower power option - although much smaller - as the 4.4 cu ft fridge needs 330WH/day and possibly even less if I added some styrofoam insulation to the door, top and sides. The condenser coils of the fridge are about an inch from the back.

[biggkidd]

Gotcha.

We are currently running 2400 watts of panel with 3600 watts waiting to be installed. For years we only had 1200 watts in 2018 I bought 4800 more watts. I put up 1200 right away and have been holding off on the rest so I don't have to put them up and then take them down to move. We are planning to build another house on the same land about 900 feet from this one. I think I may go ahead and put up another 1200 watts down here so we can save gas and still run AC and a deep freezer this summer. I move slower and slower these days so who knows when the new build will get started much less finished! Currently we are running an Aims 2000 watt pure sine wave inverter / charger which has a great motor start feature of 6000 watts for 20 seconds. I have another one just like it to add to the system when we start using the deep freezer. Which needs to happen ASAP the way things are going. Timers are a great help with controlling power use in a small system like ours. That way large draw items can not all run at the same times yet still be autonomous. 

[papaof2]

Timers are a good idea in most solar systems.  The solar lighting in the equipment shed out back - 30 watt panel, 15AH battery, LED strips that draw less than 2 amps - has a 60 minute windup timer so the lights can't be left on and accidentally drain the battery  The charge controller is also programmed to shut dowm the load when the battery drops to 12.1 volts.  The system had been running over two years and still works every time I turn it on.

If we were offgrid and not just me learning about solar power - a 250 watt panel delivers 5 watts during a typical thunderstorm and zero watts during a heavy one ;-), I'd be interested in a 4000 watt split phase Aims inverter - about $1100 from Home Depot but it needs a much larger battery bank and solar array.  I have controllers for maybe 4000 watts of solar panels - just waiting for another good deal, such as the ten used 240 watt panels for $999 that turns up on the nearest Craig's List from time to time.  The guy is a solar installer/uninstaller who has taken out some big systems.  I bought some used Jinko 250 watt panels from him that delivered 235 watts propped up in the backyard so he sells good stuff.  Just waiting for the next offer ;-)

I do get "solar envy" when I pass an office building on my way to see the eye surgeon.  With someone else driving I was able to get a more-or-less accurate count of 50 panels in one row and there are two rows of what look to be 250-300 watt panels.  That's 25KW to 30KW of what are likely grid-tie panels.  For home use, that much system might deliver nightlight power by moonlight ;-)

[biggkidd]

Guy on CL in Southill (VA/NC line) has new 315w panels for $150. Overbought or something says they come with full warranty if you're interested.

My Aims inverters are the best inverters I've used yet. My Midnite Classic 150 solar controller is good for 5000 watts at 48 volts. Recently I picked up a PowMr MPPT controller to try out on a smaller system for my shop. It's not much compared to the Midnite but can handle 2400 + watts at 48 volts. If it works as advertised I'll be happy at 1/10th the cost.

ETA: Scratch that I just looked and the ad is gone now. I was gonna add a link.

P.S. Solar fields are popping up all around here. In fact one is supposed to be built around 3 sides of our property in the next few years.

[papaof2]

I bought a PowMr after seeing several positive reviews. You do need an accurate voltmeter as the internal voltmeter on the one I have is off by at least 0.1 volt. I calibrate my voltmeter at 10 volts for 12 volt work, using an AD384 chip with its calibration sheet - down to 0.001 volt. The PowMr had to be set for 13.7 volts float to get an actual 13.6 volts for the float voltage (for some AGM batteries) so you will need an accurate external meter to get an accurate voltage. The PowMr does work as I used it with a 24 volt, 10 amp power supply as a "250 watt solar panel" to do testing after dark. When (If?) we have sun again, I'll test the PowMr with varying levels of actual solar input ;-)

My test setup:

solar -> controller -> 50-100AH battery -> 2000 watt pure sine wave inverter -> 250 watt halogen lamp with dimmer

I can adjust the load to have the battery at any discharge level and the power for recharging the battery plus the load of the lamp can easily be brought above the solar input power for real world testing.

The local guy with good prices on used solar panels is like that - you catch the ad the first day it's up or it's gone.

[biggkidd]

Glad to hear they work. I have been a little skeptical to be honest. I have the 2 Aims pure sine inverter / chargers and another 1500w pure sine inverter I can't remember the name of and a 1200w modified sine Victor brand I bought 20 odd years ago. The last one I got first and used to heat my tractor engine on the way to jobs and to run tools as needed. Don't knock it to hard it still works after 20 odd years even though it has way fewer hours of use than both the Aims do.

Well if you ever hear anything about the solid state batteries toyota and such are working on please let me know what you find out.

[9idrr]

Just wanna thank you two for sharin' some real-world info.

[biggkidd]

Happy to do it. Papaof2 has a lot of electrical knowledge, far more than I do. I might have a little more time of use or experience living off the main grid after 12 full years of it. But then again I can't honestly say he may have too at some point.

[papaof2]

biggkidd is probably a better source for information about living long term with only solar power because he's experienced the "gotcha's" of doing that - including how much gas to store for XX weeks of generator use.

I have a little over four years experience dabbling with solar. The biggest piece is the 420AH battery bank powering the 2000 watt pure sine wave inverter that goes to a four-circuit transfer switch for fridge, counter outlets, some LED lighting, etc.

We haven't had many long outages here (one 12 hours, one 16 hours but that one was BS {before solar}) but we've had a number of shorter ones (typically less than 2 hours). The entire area experienced multi-day outages from a serious ice storm some years ago. There were places in the City of Atlanta that were without power for two weeks. The worst we experienced before moving to the current location was three days without power from yet another ice storm, so those are always a concern in certain months. The idea of a battery backup system came from me not wanting to go out in the dark or a thunderstorm to get a generator out of the shed and start it. That progressed to my "Wait until daylight" solar-charged backup system. Depending on the season, it can provide 8 to 20 hours of limited power - 8 hours in winter with the high-efficiency gas furnace using 460 watts for igniter, blower, etc. In weather that needs neither heating or cooling, there are more battery hours available for the other things.

As I tested various items to see what their long-term power draw was, I found the counter-height fridge in the basement only used 55 watts and it ran less than 6 hours/day in a 78F enviroment. With that fridge instead of the 28 cu ft fridge/freezer, the current battery bank is good for 2.5 days if I power the internet equipment or 3.9 days without the internet (if it's even available during a long power outage). If you add a little solar power to the minimum power usage scenario, 400 watts keeps up if there's daily sunshine without internet, 600 watts allows for one non-sunny day. 1100 watts of solar allows for 2.4 days of internet without sun - or 3.9 days without internet - and that much solar power will charge things up on the next sunny day.

The longest we've been on the backup system is a little under 12 hours - the county had 7" to 12" of snow in a place that rarely sees more than 3" so many people were without power for a while. The electric co-op was NOT providing restoration time estimates so I decided to run the furnace for the hour before we went to bed - the overnight low was to be in the 20's (F) and I wanted to ensure the basement was warm enough to keep the pipes from freezing and ensure that the batteries would have enough charge to run the fridge overnight. Less than an hour after the generator ran, co-op power was back up. Other than the hour of gen use, we spent the outage using the backup system. Some houses were cold enough (57F) that the residents were in a car running the heater - and charging their iPhones. I suggested to one couple that they should sell one iPhone and buy a generator - never got an answer on that ;-) We had a warm space because the gas logs are totally battery-operated, both the remote and the gas valve, so we had heat for a small area at the touch of a button.

[biggkidd]

Gas storage is or can be a double edged sword. It's great to have and rotating stock is a big plus. Used home heating oil tanks are good storage vessels. A 55 gallon drum plumbed to a generator save a lot of pouring cans and a pickup bed transfer tank with pump is almost a must. During summer running the house and using AC we have gone through as many as 4 gallons in 24 hours with an EU2000i. IF we had the battery storage we wouldn't hardly use gas. But it's all a trade off one way or another. Last year I think we averaged about 2 gallons per 24 hours. This year I am expecting to use 1 or less IF we hook up another string of panels (1200w). For the last couple months we wouldn't have needed any gas except I wanted to start garden plants under lights with heat and all so that ran me about a gallon a day maybe a little less. I try hard not to run my batteries below 70% and 80% would be better. So using only 20-30% of their capacity.

When it comes to power systems the biggest problem people have is understanding that just because you have XXXX amp hours at a given voltage doesn't mean you can use all that power. Simple example let's say you have 1000 amp hours at 12 volts. Now NOT counting the power all the electronics consume to work. If you take 1,000 AH at 12 volt and invert that to 120 volt. Theoretically that gives you 100 amp hours at 120 volts. But you can not actually pull 100 amp hours out especially if you want to get the best life out of the batteries. Realistically you can take out 20-30 amp hours at 120 volts from that 1,000 amp hour 12 volt bank. BUT you still have all the little losses and the power consumed by the equipment to make it all work so discount another 10% or so that's just gone. Then you also have to remember that you consume more energy recharging than you pulled out. So let's say you take out 20 amp hours now you have to put back 25-35 amp hours depending on a lot of factors this number can swing quite a bit. ALSO something people often miss is the difference that the speed of discharge makes to how much power you can actually use. For example some of the batteries we've had were rated on 3 scales 8 hour discharge 20 hour discharge and 100 hour discharge. The batteries were rated to hold say 100 amp hours at a 20 hour discharge. So at an 8 hour discharge you only have about 75 amp hours or with a 100 hour discharge rate you might have as many as 125 amp hours. I always try and work with a 20 hour rate since we are primarily solar powered and the batteries charge for about 4 hours in 24 hours. Now something you can do to help this a little is to point your panels in slightly different directions south east, south and south west for the northern hemisphere. Of course auto tracking panel mounts track through the day. BUT that's another something to breakdown and another added expense. Personally I think having more panels facing SE, S and SW is the better option. Plus it takes some strain off your equipment. By spreading the load over the entire day instead of getting max charge for 4 hours. YMMV

I have NO PROOF but I believe the closer you can keep all your voltages to the same the more efficiently everything works. Household current 120 volts is two legs at 60 volts each a 48 volt battery bank is about 50 volts so not a whole lot of power consumed shifting that voltage from 50 to 60. Yet going from 12 volts to 60 is quite a jump. This doesn't even take into account the cost of wire which can really add up. A 12 volt system uses battery cables larger than a truck while a 48 volt system can use 10 gage wire often times. Then there is ease of installation . . . Try bending some 0000 cable versus 10 gage!

I'll stop here since y'all are probably bored to death or quit reading way back. lol

[papaof2]

My spreadsheet for hours of power from the battery bank includes a place for the inverter's idle current and its efficiency, both of which are involved 24 hours a day. With my system effectively being a "big UPS", I will discharge the batteries to 50% in backup service. The AGMs are rated for perhaps 1100 charge/discharge cycles at that depth of discharge (DOD) and while that would only be three years of life at that level of daily use, my system isn't likely to be used more than once a month. Those numbers work out to some 90 years so I'll go with the manufacturer's 5 to 7 years of life, although I didn't replace the previous battery bank until it was almost 9 years old (they had lived in a data center UPS before I got them).

If my initial goal had been long-term power, I would have opted for at least a 24 volt system, instead of the 12 volt system I have. However, lots of 12 volt devices are available for vehicles so that was one of the reasons for using 12 volts as my starting place. Based on the loads I plan to support, the very short 4 gauge wiring between the batteries and between the batteries and the inverter are adequate - I did lots of research on that - and I have an inch-lb torque wrench to ensure the connections are tight enough but that I don't strip any threads.

With similar inverter designs, a 48 volt DC to 120 AC inverter is likely more efficient than a 12 volt DC to 120 volt AC inverter simply because of lower wiring losses with the lower currents on the DC side. Not having the stock of equipment to do that type of testing, it will remain a logic problem for me ;-)

I base my battery AH numbers on the 20 hour capacity for the same reason - it's basically a 24 hour system.

There's a paper from a battery manufacturer that has their research on recharging lead-acid batteries (any flavor) and the recharge is 107 to 115% of the discharge amount, depending on the battery, its age and several other factors. I have an in/out AH meter on the battery bank and my goal after using the backup system is to put back at least 10% more AH than was taken out - at least 10% because that's an easy number to do math with ;-) The in/out meter counts up when discharging and down when charging so if you discharge 100AH then charge 100AH, you get 0AH and you let it charge to at least a displayed -10AH (10%). 10% is easier to work with in your head than 15% - 10% of 83AH is 8.3AH but 15% of 83AH is 12.45AH so "at least" 10% seems the easiest way to meet this requirement when you've been up 20+ hours.

[biggkidd]

You're a lot smarter than I am. Often times I've wanted to take a few classes on electronics but I could never find anything suitable to what I wanted to learn that I was willing to spend the bucks for.

Length of run does make a HUGE difference in cable size as well as voltage. My runs were longer and some places have codes stipulating the batteries CAN NOT be in the same space as the electronics.

[papaof2]

AGM batteries are sealed and are used on handicap scooters and electric wheelchairs to meet air travel restrictions so I'm comfortable having them share living space (in the basement) with the solar controllers and the inverter hanging from the same shelving rack.

Don't know that I'm smarter than you are but I have been dabbling in eletrical/electrronic things most of my life. I was about 10 when my grandfather was changing out the motor on the window fan and he asked me to read the directions for changing the motor's direction of rotation - I was hooked ;-) I've been learning ever since. There are (were?) some decent "Beginning Electricity" books and there are probably videos on Youtube - I know that Will Prouse did one on volts, amps and watts and there are many "How To" videos.

[biggkidd]

May 12, 2021 14:27:20 GMT -6 biggkidd said:

Guy on CL in Southill (VA/NC line) has new 315w panels for $150. Overbought or something says they come with full warranty if you're interested.

My Aims inverters are the best inverters I've used yet. My Midnite Classic 150 solar controller is good for 5000 watts at 48 volts. Recently I picked up a PowMr MPPT controller to try out on a smaller system for my shop. It's not much compared to the Midnite but can handle 2400 + watts at 48 volts. If it works as advertised I'll be happy at 1/10th the cost.

ETA: Scratch that I just looked and the ad is gone now. I was gonna add a link.

P.S. Solar fields are popping up all around here. In fact one is supposed to be built around 3 sides of our property in the next few years.

After ten years my midnite solar controller needs repair. It's my fault I knew the fans were going bad and got new fans in but hadn't changed them yet and It cost me. Anyway I am currently using the PowMr 60 amp controller. It is working although it is getting much hotter than expected, enough so that I put a box fan blowing on it. I'm guessing the internal meter isn't to good either since it claims my 2400 watts worth of panels are producing 2600 watts today. I don't have another way to check that.

[papaof2]

I found the internal metering on the PowMr to be a little optimistic - showing more power than the volts and amps multiply to. I did spend the bucks for a clamp-on DC ammeter so I can check current as easily as voltage - nothing needs to be disconnected. The inline V/A/W/AH/WH meter on the battery bank is rated for 200 amps max and was maybe $35 from banggood.com. It's not really accurate at low power levels but the V/A/W numbers are close to what the EPEver charge controllers and the external volt and amp meters read, plus AH in/out numbers are good enough for determining when there's been 10% more charge than discharge. I tested a MakeSkyBlue controller and found the voltages off by 0.2 volts (not good for lead-acid batteries and destructive for lithium) and that the watts were VERY optimistic. There's a video on Youtube by someone who's more enthusiastic than knowledgeable: he goes on and on about the MakeSkyBlue delivering much more power than his panels are rated for :-(

If solar were our primary power, I might have opted for MidNite or equivalent instead of the EPEver controllers I'm using, but the EPEver controllers are convection cooled (big heat sink on the back). The 30 amp EPEver (390 watts at 12 volts) runs cool with 320 watts of power running through it. I know that MidNite inverters have genuine "peak" power ratings because they have time associated with each rating: 30 minutes, 5 minutes, 30 seconds. I have two 2000 watt pure sine wave inverters (active and spare but the spare could also be used with a larger battery bank). I measured or computed the peak power on each appliance and that's in the spreadsheet. If the peak power exceeds the continuous power rating by more than 10%, the spreadsheet cell changes color to warn you.

I'll get my second chance exploring lithium technologies in a week or two (first time was a lithium ion battery pack to replace a NiMH battery pack in an ancient hand vacuum). I have several low power inverters from the APC Back-UPS Connect series, purchased when newegg.com and Office Depot had them for sale for less than the price of the battery inside. These are designed for longer power on low loads (max is 75W, 125VA) and I have one on the home network equipment, one on the U-Verse "terminal" and one powering the cordless phone, the house alarm console and the talking Caller ID unit. That last one ran about 6-7 hours during a 12 hour outage but died about an hour or so into the most recent (2 hour) outage. The battery is available for these now-discontinued UPS units: $27 from upsbatteries.com or $50 + shipping from the manufacturer. It's an odd size 12 volt, 4.2AH AGM battery and UPS battery life is rarely the advertised "3 to 5 years" so I looked for a better option. I found 26650 LiFePO4 3.2AH cells for $3.05 each (in a case of 16, incl. tax and shipping from batteryhookup.com) and the correct 8A BMS units for $4.60 each (incl. tax and shipping from Ebay). With 4 cells to make a 12 volt battery, the cost is 4 * $3.05 = $12.20 + $4.60 = $16.80 plus a little of my time - plus the batteries are rated for 2000 cycles to 80% DOD. That's $10 cheaper than the lowest price for the AGM battery. I already have the spot welder and the nickel tape for welding up a battery pack so I'm looking forward to seeing how well these cells work. It's a one time deal on the cells as they are surplus from a military electric vehicle project and, when gone, there will be no more at this price :-( If I had an extra $300, I'd have bought a case of them for future projects (some "12 volt" drills I got for free on Craig's List, but those will likely get lithium ion 18650 cells from "dead" Ryobi 40 volt packs). If the LiFePO4 cells are even 20% as good as they seem, I probably won't replace them for a very long time and I'll have another learning experience ;-)

[papaof2]

A V/A/W/AH/WH meter similar to what I have on the battery bank is under $50 delivered from Banggood in whatever amp capacity you need, from 50 amps to 500 amps:
www.banggood.com/DC-500V-50A-100A-200A-300A-500A-Wireless-Voltage-Meter-Ammeter-Solar-Battery-Charging-Coulometer-Capacity-Power-Detector-Tester-p-1721288.html

This one uses a Hall effect sensor to measure amps, so you only need to disconnect a cable from the battery bank, run it through the sensor and connect the cable back - no new wiring or bare terminals involved. The display can be remoted from the other electronics but the range on the one I have is just shy of what's needed for the distance from the battery bank to the kitchen counter so it's hard-wired at the battery bank and I must take the 16 steps down to the basement to check it.

[papaof2]

The batteries are in the hands of FedEx with a promised delivery date of Sunday. The last two battery deliveries via FedEx were pathetic, with one claiming to have been left "on the porch" and "signed for by MM". There was no package, we were home all day and we don't know a neighbor with the initials MM. That package turned up on the porch - much worse for wear - three weeks later. The other one was "weather delayed" (there was light rain BEFORE the truck left the FedEx depot) then a couple of "no attempt made" days and so forth until it finally showed up - by then I had a "record on motion" camera set up watching the road and the delivery person was in a generic Penske rental truck and not wearing any type of uniform - FedEx was apparently scraping the bottom of the barrel for delivery drivers.

The BMS units are coming from Taiwan with a delivery date of 27 July. If FedEx matches its previous delivery quality, the BMS's might get here about the same time the FedEx delivery gets here...