tikigeorge wrote:Get a whole house propane generator and this will solve your issues:-) A easy fix! No worries about the sine wave issues too.
Gekko wrote:tikigeorge wrote:Get a whole house propane generator and this will solve your issues:-) A easy fix! No worries about the sine wave issues too.
I have an older 17 KW generac I got free from craigslist. It needed a fwd crankshaft oil seal, battery, GCU CB, and the transfer switch panel. The only thing I did not do myself is the transfer install and twin 120 gal propane tank install. It cost less than 2 grand all up.
This also ads significant marketability and value to any house.
lsayre wrote:Rob R. wrote:So what kind of battery bank is needed to meet that demand?
A battery bank that is huge! Assuming that as a rule you only ever want to discharge a deep cycle battery bank to 50% of full charge, and using a midrange one day demand for the coldest day of the year of 8,000 Watts required (8 KWH), and assuming a 24V inverter I get:
8,000 Watts / 0.5 (for 50% discharge) = 16,000 Watts worth of batteries
16,000 Watts / 24 Volts = 667 amps worth of batteries. Multiply times 1.1 for the typical 90% inverter efficiency and you get 734 amps.
3 parallel wired banks of 245 amp rated 6 volt deep cycle batteries, each bank leg with 4 batteries (since 6V x 4 = 24V) would do it. The 3 banks in parallel would deliver the required 734 amps (3 x 245 = 735 amps). 12 batteries total. For average winter days this should provide up to 4 full days of boiler operation on batteries alone, but on the coldest single day in the past 10 years it would only (perhaps) provide 1 full day of heat.
The first battery seen on this website would come close. http://www.altestore.com/store/Deep-Cyc ... Acid/c435/
12 x $200 = $2,400 for the batteries.
........... So you would have to have 55 galls on hand when the SHTF. You can't store 55 galls as it will degenerate. ........
McGiever wrote:I think you are interchanging Amps w/ Amp hours (Ah)...they are apples and oranges, like Watts and Watt hours (Wh). Perhaps your math is all good, just labeled incorrectly.
100 gallon tank for a 17 kW genny? Stupid indeed. All they had to do was crack open the Generac manual and read the page about tank sizing.
scalabro wrote:Don't forget Larry that for any AH rating with a lead acid battery, you will only get about 85% of its rating in a fully charged state, during real world ops.... ie 2.2 volts per cell open condition. So what ever you do, add another 15-20% AH larger batts.
I've got a friend that powers his cabin on a bank of old 24v Ni Cad aircraft batteries he scrounged over the years at work. It works ok. I think he has 20 or so 44AH 24v batts in parallel.
coalnewbie wrote:100 gallon tank for a 17 kW genny? Stupid indeed. All they had to do was crack open the Generac manual and read the page about tank sizing.
Whether it's 100 or 10,000 gall it's still $150-200 a day to operate, plus exercising expenses. If you want it that bad then fine. Then it's how long you want prepared to be down for. 1 hour or one month. SHTF times are unknown. A fools errand. Blessed are the peacemakers.... Security is an illusion. All my Lister cs6/1 stuff is being sold off right now. They will burn just about anything and my HO tank will keep them running for a long time... One guy is coming up from Georgia to look and intends to run them on peanut oil (Rudolph Diesels original fuel)... He expects to get one million hours between overhauls. No electronics, no over crank messages etc.
It's still an illusion.... candles and a coal fire.