Grid Tie Battery Bank - AGM sealed or deep cell?

[Naptown]

I don't know what three phase or single phase means.

Thanks

Your house is single phase it would cost a fortune to have the POCO convert to 3 phase

[MrEnergyCzar]

I have seen large three phase battery chargers and I am sure they are available in single phase

I don't know what three phase or single phase means.

Thanks

[Naptown]

I have seen large three phase battery chargers and I am sure they are available in single phase

[MrEnergyCzar]

So if they don't make larger AC battery chargers it looks like I'm relegated to using my Volt's 16KW lithium battery and onboard gas generator to back charge smaller (1,800w) AC battery chargers. I can get a constant 1,000 watts out of the car, 2000 surge, use a couple of gallons of gas every 24 hours. The gas numbers seem low but that's what owners reported during Sandy. The engine comes on a few minutes every hour. When the engine runs it produces very large KW to charge the battery back to 40% state of charge rather fast. I'll have to run a cord from the Volt and play musical chairs with AC portable battery packs to run fridge and pellet stove etc... the biggest ac battery charger I've ever seen is on northern tool and can handle a 3,600 watt surge to be used for the fridge. There aren't any rules yet against using your plug-in engine to power the home, yet anyway.

Anyone know who has a larger AC battery charger? It would be nice just to have one instead of several small ones.

Anyone here have grid tied FLA batteries? If so, have long have they lasted or how long do you expect them to last.

Thanks
MrEnergyCzar

[Sunking]

Don't work in Connecticut

Pay the $150 Fee for the reciprocal license and take the money. Best $150 investment you will ever make.

[Naptown]

He does not want to hear that Rich. You are in the biz of selling solar stuff and close by him. Take his money and laugh all the way to the bank. With the proceeds you can send one of your kids to college or pay off your home loan at his expense. Trust me he wil be happy and thank you for it.

Don't work in Connecticut

[Sunking]

The size of the battery bank just doubled.
And the northern with the solar panel at 80W won't even be enough to be a battery maintainer on that size bank.
You realize you are talking about a 100KW battery now.
At 48V that is a 2000AH battery bank and would require 24 2400AH batteries at about $1300.00 each. or about $32000.00
or more when you include shipping.
To keep those charged with solar would take 11.5KW of solar and 8 80A charge controllers.

He does not want to hear that Rich. You are in the biz of selling solar stuff and close by him. Take his money and laugh all the way to the bank. With the proceeds you can send one of your kids to college or pay off your home loan at his expense. Trust me he wil be happy and thank you for it.

[inetdog]

The size of the battery bank just doubled.
And the northern with the solar panel at 80W won't even be enough to be a battery maintainer on that size bank.
You realize you are talking about a 100KW battery now.
At 48V that is a 2000AH battery bank and would require 24 2400AH batteries at about $1300.00 each. or about $32000.00
or more when you include shipping.
To keep those charged with solar would take 11.5KW of solar and 8 80A charge controllers.

Yes, but it's FREE.

[Naptown]

The size of the battery bank just doubled.
And the northern with the solar panel at 80W won't even be enough to be a battery maintainer on that size bank.
You realize you are talking about a 100KW battery now.
At 48V that is a 2000AH battery bank and would require 24 2400AH batteries at about $1300.00 each. or about $32000.00
or more when you include shipping.
To keep those charged with solar would take 11.5KW of solar and 8 80A charge controllers.

[MrEnergyCzar]

That would be an understatement. The USA has now taken the #1 spot in proven reserves when back in 2007 we were way down the list. You, your children and grand children will not see peak oil. We have only scratched the surface for exploration.



Yes but here is the part that you seem to be ignoring and do not want to hear or know about. Define your daily Kwh usage. What is it?

For example let's say it is 5 Kwh/day and you want 5 day capability for emergency power when the grid is down. To keep from damaging FLA batteries you do not want to go below 50% DOD, so you need 10 day Autonomy. That means you need a battery with 10 days x 5000 wh capacity = 50 Kwh. A battery that size weighs some 3000 pounds and cost about $11,000 that needs replaced every 5 to 7 years. It also means you have a garage full of batteries on reenforced concrete the size of a King Sized bed. That is not even including all the equipment to support it.

I use 10 KWH per day. Why would FLA batteries be replaced after 5 - 7 years? When I subscribed to home power magazine it was pretty clear, with maintenance, they'd last 10-15? That's one thing I remembered. I've searched for appropriate sized AC battery chargers and have only found up to 1,800 watts with surge of 3,600, where are there larger ones because that could solve a lot of power outage issues. Northern Tool and Sneider Electric only go up to 1,800 watts. Nothern has the one with solar panels built in but takes 3 days to recharge with 80 watt panel. Any suggestions on where to get one?

Thanks
MrEnergyCzar

[Sunking]

Those are nice generators but I'm preparing for peak oil, I know a loony topic

That would be an understatement. The USA has now taken the #1 spot in proven reserves when back in 2007 we were way down the list. You, your children and grand children will not see peak oil. We have only scratched the surface for exploration.

So it sounds like if someone had a large battery bank, they can equalize it with the grid each month and have a few days back-up power when the grid went down, with a solar array they can go longer. If there was no generator when the power went down, can the battery bank be shut down before the DOD reached near critical levels?

Yes but here is the part that you seem to be ignoring and do not want to hear or know about. Define your daily Kwh usage. What is it?

For example let's say it is 5 Kwh/day and you want 5 day capability for emergency power when the grid is down. To keep from damaging FLA batteries you do not want to go below 50% DOD, so you need 10 day Autonomy. That means you need a battery with 10 days x 5000 wh capacity = 50 Kwh. A battery that size weighs some 3000 pounds and cost about $11,000 that needs replaced every 5 to 7 years. It also means you have a garage full of batteries on reenforced concrete the size of a King Sized bed. That is not even including all the equipment to support it.

[MrEnergyCzar]

Certainly but if you do that then you have absolutely no reason to have solar. You would just buy an appropriate sized AC powered battery charger.

If you were my client I would advise you to install Generac 6 Kva EcoGen right next to your Heat Pump to power your whole house. At 52 db noise level you can sleep with it in the same room with you.

Those are nice generators but I'm preparing for peak oil, I know a loony topic, so limiting fossil fuel directly as an end user is important. So it sounds like if someone had a large battery bank, they can equalize it with the grid each month and have a few days back-up power when the grid went down, with a solar array they can go longer. If there was no generator when the power went down, can the battery bank be shut down before the DOD reached near critical levels? That's an important question for me to know as well as how long in winter will a decent FLA bank take to deplete from 35% Dod to say 50%? I'm guessing on what safe levels are. I understand I can equalize the battery with the grid after the power came back on the next week. I assume doing it after 5 weeks versus 4 weeks once per year is not catastrophic. One could also equalize them before a pending large storm as well. I assume it wouldn't hurt to equalize them a week earlier before a storm, although I could be wrong.

Interesting you said to just buy an appropriate sized AC powered battery charger. I started with that 5 years ago and got a 1,500 watt battery pack on wheels, the largest I could find. They make an 1,800 watt one with attached solar panels but I have never seen a larger one. I don't think you can attach them into the electric panel anyway. I run my pellet stove for 12 hours with it and back charge it with my Volt. I can get 1,000 watts continuous with my Volt but, again, it's not tied into the panel, just extension cords. Do they make a large AC powered battery charger????? Sorry about so many questions but I've wanted these answers for quit awhile.

Thanks
MrEnergyCzar

[Sunking]

Can't you use the Grid each month to equalize the batteries?

Certainly but if you do that then you have absolutely no reason to have solar. You would just buy an appropriate sized AC powered battery charger.

If you were my client I would advise you to install Generac 6 Kva EcoGen right next to your Heat Pump to power your whole house. At 52 db noise level you can sleep with it in the same room with you.

[MrEnergyCzar]

I would only do that proposed set-up on large land in a less regulated state than CT. Can't you use the Grid each month to equalize the batteries? If the grid happened to be down that day you wanted to equalize, how long is the window of time to equalize again? One day, One week?

Thanks,
MrEnergyCzar

[Sunking]

Bear with me here with my questions, If you had a grid tied "small solar farm" that was say, 50KW, and your home only needed a 2 KW array, and the battery bank was large, 10 days autonomy, couldn't in theory you go without a generator in that scenario?

OK Deep Cycle Flooded Lead Acid Batteries have a rather small window of charge current needed to keep them maintained properly. The minimum recommended charge current is C/12, and maximum is C/8 where C equal the battery 20 hour Amp Hour rating. For example if the battery is rated 100 AH the C/12 rating is 100 AH/ 12 H = 8.3 amps, and 100 AH/8 H = 12.5 amps.

The minimum charge current although not set in stone is because of what is known as stratification in flooded lead acid batteries where the heavier acid settles at the bottom of the jar and the water on top. It takes at least C/12 charge current to cause bubbling and agitation to stir the mixture up and prevent agitation. One way around that is to have a generator with a AC charger of sufficient capacity to apply the monthly Equalization Charge required for FLA batteries. A solar system is not capable of supplying an EQ charge because the EQ charge can take up to 24 hours.

The maximum C/8 charge limit is to prent the electrolyte from boiling over, gassing the batteries, and warping the plates.

Normally this is not a problem with a properly designed system with 5 day Autonomy, and where winter minimum Sun hour are 3+ or more hours, or summer above 6 hours. For example if you live in KCY with 3.3 Sun Hours in winter, need 1 Kwh/day on a 12 volt battery with 5 day autonomy. Battery required is 12 volts @ 400 AH. Panel wattage required with MPPT controller = 450 watts, Charge Current = 37.5 amps or a C/10 which is spot on perfect. However if you increased the Autonomy to 10 days like you suggest is a 800 AH battery and with a 450 watt panel generating 37.5 amps is only a C/20 charge current. Not going to work out and the work around is now you need at least a 850 watt solar panel and a very expensive 80 amp charge controller to maintain the batteries.

If you think it is hard to pull a permit with a generator, how hard do you think it will be to pull a permit with 2000 pounds of extremely toxic batteries on your property that will take a EPA permit and yearly inspections from your local fire department to inspect your spill containment system and check for leaks. You would be require to put one of those funny looking diamond shaped HAZ-MAT Signs with the 3 colored diamonds with number in them at your property entrance to warn people and First Responders there lives are in danger upon entering. Bet that will go over real good with the HOA.