LiFePO4 180AH cells for $95 + tax + ship

[papaof2]

batteryhookup.com/products/calb-ca180-3-2v-180ah-lifepo4-prismatic-cell-90-100?mc_cid=6bac266b20&mc_eid=7c6358641e

UPS shipping for 16 cells is about $150 to Atlanta. Work from that or go to the page, select how many cells you need and use their shipping calculator. 16 cells is about 200lb. That's 180Ah at 48 volts, 360AH at 24 volts, 720AH at 12 volts.

Rated for 2000 cycles to 80% DOD. 2000 cycles is 5.48 years at one 80% discharge / day.
They would last much longer than that in typical solar service where you design for much smaller maximum daily discharge.

Our typical winter "power's out" usage would reach 80% DOD on a 720AH battery bank after 30 hours with no charging input from solar or a generator. If I take the manuals' ratings, the fridge can be without power 8 hours & be OK. The freezer can be without power for 24+ hours & be OK. If I left the fridge unpowered for the first 8 hours and the freezer unpowered for the first 24 hours, I'd have about 48 hours of our typical "power's out" backup with no charging of a 720AH battery bank (about $1800 delivered). Remember that I have most of the other pieces because I've been collecting bits (including some 120 amp BMS units) for a long time. The 120 amp BMS is fine because the maximum power for a 2000 watt sine wave inverter that's 85% efficient is 2000 watts / 13 volts / 0.85 efficiency = 181 amps. If only two strings of the batteries are working, two 120 amp BMS units can provide 240 amps so well over the 181 amps needed. Using a 120 amp BMS limits the output of the cells to 2/3 of their 180 amp rating so the cells can't be over-stressed. (Does it sound like a pessimist is doing the design?)

If I can persuade the better half... Maybe pray for a 48 hour snow outage the second weekend in December? Maybe 12-14 inches of snow? We had 12 hours of outage from 7 inches 6 years ago but the outages were MUCH longer in other areas of the county which had more snow - up to 12 inches.

[feralferret]

Hopefully they will run another sale after I get moved and my house sold. I'll have some available funds at that time for building up a proper system. Since my daughter's house (where we are moving) is all electric, I have to work up some alternatives. At least she has a functional fireplace. I hope to pickup a suitable smaller wood stove to run through the fireplace chimney. Gas logs are not an option as there is no gas line to her house, even though natural gas is available there. I never did think that all electric houses were a good idea, even back in the 60s when they were all the rage.

A bit of electrical work will also be required. My youngest son, who also lives there, will have to be my hands for any work requiring using ones hands any higher than the top of my head. It really stinks being old and decrepit!

[papaof2]

I definitely walk a similar "can't do that anymore" path. I have a trigger finger on the left hand that has become almost unusable. It's the index finger which has 80% of the strength of the hand so there are a lot of things I can't do with two hands or that I do with the left hand in a very awkward position. I've talked to the hand surgeon about it (he was impressed with the motion limiting splint I made to sleep in - it only limits motion of the first joint (near the fingernail) but that's enough to prevent it getting into a locked position when I'm asleep. The middle finger of the right hand occasionally tries to lock but I'm aware of it so I can almost always prevent that. I had the middle finger of the left hand done 20+ years ago and the surgeon had to do some adhesion release when he did the thumb surgery a year or so back. I'm very aware of the recovery time from that surgery so I'm trying to keep both hands functional for another 3 to 6 months. Surgery on the left hand will likely be more involved than the usual relatively simple "release" surgery for trigger finger so it will be first and I'll have a 90% functional right hand while the left hand is in PT.

I can't have that surgery now because the better half is still recovering from wrist surgery on her dominant hand and I'm her "other hand" as often as needed - including cutting and fitting scar tape to help with the scar healing and to provide a layer of protection when she's asleep so rough cloth surfaces (blanket edge, etc.) don't irritate it enough to wake her. The hand being cold also triggers some pain so she sleeps in one glove. During mechanical recovery, whatever works or eases pain is a good thing.

If the part of the chimney is outside, you might be able to bring a gas line in that way (100lb / 20 gallon LP tanks can be hidden by shrubs or decorative fencing ;-) and some gas logs come with a natural gas input on one end and an LP input on the other end (the set we have). Most unvented gas logs can be used in any wood-rated chimney - check the manual for the logs. Our gas logs are listed a "unvented" but can be used wither way. I opt for unvented 99+% of the time - there's a metered CO detector about 10 feet from the gas logs so we'd get immediate notice of a problem. I did the numbers based on LP BTU/lb and two 100 pound / 20 gallon tanks would run 30,000 BTU gas logs 16 hours/day for 24 days. With an 80% tank fill, that's 32 gallons at a price around or a little less than unleaded regular - but that varies by state/area and can have huge variations between even adjacent states. LP has 91,500 BTU per gallon and is 4.11lb/gal @ 77F. I think I posted the link to finding propane prices historically by state a while back.

I had to put some restrictions on things that can / can NOT be used when on backup power but with no power in the bathroom there's not a good place to use a hair dryer and I have some luggage locks with shackles small enough to fit through the holes in the plug on the microwave cord and a few other high power things if needed. With just the two of us, that's not a problem but if we had other people here the locks might be mandatory. Not being able to do a lot of wiring while standing on a ladder, very little got rewired other than the few circuits I ran over to the Gen-Tran switch. I'd like to have a bigger transfer switch but the new 6 circuit, 30 amp, 8000 watt kit from Reliance is now $400 at Amazon:
www.amazon.com/Reliance-306LRK-6-Circuit-Transfer-Switch/dp/B09FGB78KK

However, I did find as a $70 plus tax & shipping "Black Friday" deal at a supposed Home Depot outlet: SCAM!! SCAM!! SCAM!!
homedepotonsale.com/products/reliance-8000-watt-generator-transfer-switch-kit-306lrk?variant=25499560/?

I need to look at the details on that one ;-)
I looked :-( It's $69.98 plus $69.98 for the next 7 days. That's $560 or almost 50% more than Amazon. Wonder how many people just clicked "Use credit card" and missed the "Apply and subscribe" at the bottom of the page...

Think I might check ebay...

They're a little better than Amazon:
www.ebay.com/sch/i.html?_from=R40&_nkw=306LRK+transfer+switch&_sacat=0&_sop=15
. . $250 w/local pickup, $258 - $260 + tax w/free shipping

The 306LRK kit has the six breaker panel with a pre-wired pigtail to go in the breaker box and the inlet connector and box. I'm really looking for just the six breaker panel w/pigtail as I don't want to drill the cement-filled concrete block plus brick wall (almost 12") when I can get a heavy duty extension cord in under the edge of the garage door. Putting the inlet in a soffit would get around drilling brick but would mean needing a ladder to connect / disconnect the gen.

I need to spend a little more time on ebay...

Worth doing some searching for the size transfer panel you need - 6 circuit, 10 circuit, etc. Some used at decent prices. One used 6 circuit at a very good price but the picture does NOT show the length of the pigtails. I send the seller a message about that. Hopefully he'll get back to me before it closes at 6PM today.

[papaof2]

Link to propane prices:
pawfiction.proboards.com/thread/2256/price-propane

[papaof2]

Link to some tent stoves:
www.amazon.com/shop/adventureswithspackmann/list/H2XFJJ3FY6DH

You might find one that will fit that fireplace.

[feralferret]

I already have a six circuit transfer panel here that I intend to uninstall and take with me. I installed it, so I know how to restore everything back to normal.

[papaof2]

I did find a used 6 circuit switch on eBay for $143 delivered. Now I need to have a day when I feel well enough to:

1. remove the 4 circuit switch and replace it with the 6 circuit (The 4 circuit box was purchased when the gen was an 1850 watt Coleman. Fridge, furnace, freezer had power.)

2. Add the 6 circuit switch and add some things for the times I have a bigger gen running

Still thinking about those possibilities. The remove and replace is the least work as the 6 circuit unit is exactly the same size and has the same mounting ears as the existing 4 circuit box, the breaker box won't need another hole and I won't have to mount another piece of plywood on the concrete block wall to have a place to mount the 6 circuit box. In either case, all 6 circuits will likely be 120 volt as I don't plan to run any 240 volt appliances (central air, clothes dryer).
Just need a day when I think I can manage that much time standing so that whatever I disconnect gets reconnected before the end of the day. If I had a 2000WH power box, it wouldn't matter as the fridge and a few other necessities could be powered from that box by extension cords while I took an Rx-pain-med-aided nap for a few hours ;-)

The individual breakers on the 6 circuit unit are 20 amps instead of 15 amps and the wiring is 12 gauge so I could allow limited use of the microwave or some other kitchen appliances when I'm using a 3000 watt or larger generator. That means I'll need to update the "How To" sheet on using backup power - for the fourth or fifth time. Nice that I've been able to improve those things over almost 20 years ;-) I'll also need to make up a cord for getting power to the 4-wire 240 volt inlet on the 6 circuit box from the two bridged 120 volt outlets on the 3000 watt gen. The 5000 watt gen has a 12/3 w/ground cord to a metal box with double duplex outlets (one on each side of the split 240 line) and a plug for the 240 volt outlet on the 5000 watt gen. Might be as simple as having two 12/3 males on the input of the 6 circuit box and running extension cords to the outlets on either the 3000 watt gen or the outlet box for the 5000 watt gen. Maybe I was thinking ahead when I made that double duplex outlet box for the 5000 watt gen?

I do have a multi-hour project that is all inside work. Maybe have the inverter gen running so I can have a small electric space heater where I'll be working in the basement (unconditioned space) if it's a cold day?

[papaof2]

As of this post, they still have more than 2000 of these batteries in stock and price is now down to $80 each.

I need to talk to the better half about spending $1500...

16 of these cells would make a very nice 12 volt battery bank of effectively 4s4p and I have the 120 amp BMS units for four 4s battery packs. (Max of 181 amps for the 2000 watt pure sine wave inverter at full output so the output of two BMS' is more than enough. Probably fuse each battery at 150 amps as secondary protection. Definitely need an insulating cover for each battery's terminals or maybe for the bank. 120 amps * 13 volts = 1560 watts * 85% efficient = 1326 watts and the maximum expected load is 1350 watts so one BMS might be adequate with some careful watching how much power is being used when. No guarantees that all my numbers will apply in the real world but they've been close for the smaller bank of less capable batteries.)

Based on my spreadsheet, we'd have 36+ hours of fridge, furnace and limited LED lighting with no input from solar or a gasoline generator. If no sun, we'd need about about a gallon of gas a day in the inverter gen to keep things charged if the outage ran more than 36 hours - maybe 3 hours in the morning and three hours in the evening? Gen is rated at 6-8 hours/gallon at half load so ~15 gallons of stored gas should cover about 2 weeks and then there are the vehicle tanks. Considering some of the "entitled" neighbors, I'd probably need to build a sound cover for the gen - don't want them asking "Where do I plug in my house?"
Sunny days and 1100 watts of solar give us maybe 3 days without using the gen. Leave the freezer off for the first 24 hours and then run it until cool and leave it off another 24 hours and run it until cool (manual says OK without power for 48 hours but I'm a dedicated pessimist) but still maybe close to 3 days before needing the gen. For another $1500 or so, I could get 300AH cells but don't think we have that many $$$ this year :-( Perhaps better to have ~2 days of silent backup than to wait with things falling apart in some places... With a little shadetree mechanicing and/or sharecropper engineering, I could add running cold water by using just a bit of that power - there's enough rain in typical years to support 2 gallons / person /day at least 10 months of the year. 1 gallon / person / day is almost guaranteed all year.

[feralferret]

I had a major change of plans. I bought a 10 circuit 100 amp manual transfer switch at auction for $141.45 including tax. I won't have to move the six circuit after all. List price was $400.

[papaof2]

Great deal!

[papaof2]

As of today, the cells are $74 each and they have about 2000 available.

[papaof2]

Today the cells are $69 each plus tax & shipping and they have about 1300.