Just because you have a big inverter does not mean you have to use all of it. I've seen a draw of 276 amps on my 3k Magnum. That happened during testing and I did not realize I had the water heater on while running the fridge, and the roof air conditioner.
The telecom batteries I got at the Interstate store and the come with a 6 month warranty. They are 12 volt @ 139 amp-hours.
Because telecom requires 100% reliability the batteries are changed out on a yearly basis. They are a 10 year design life with a 3 year warranty. The chances are mine have only been in service for one year and that they have never been deeply discharged.
I was going to spend over $3600 for Surrette batteries. The telecom's will come in at about $480.00 Even if they only last 2 years I'll be money ahead. I've managed to get ten years out of my Marine Walmart flooded batteries.
Because they are an AGM variant they may exhibit far less voltage drop than golf cart batteries. They can also be recharged at the C/5 rate.
I could have gone with six jars but for now I'll do just four. They will be installed either next Sunday or Monday.
If you go with 48 volts you could have 2 banks of 4 each with simple switching for selection.
sushidog wrote:
Where does one shop for used telecom batteries, and do they come with any guarantee? If I went with 8, 139ah 100lb telecom batteries (wired series and parallel as I assume they are 12v) that would still be 800 lbs of batteries for 278 AH (.35ah/lb), vs 8, S-550s at 984lbs for 428ah (.43ah/lb) though at higher cost. How long can I expect used Telecom batteries to last? I'm sure they are replacing them because they are old and have lost much of their life and capacity, right?
The heat pump runs on native 48v DC drawing 11.5 amps to make 12,000 BTUs of cooling and 12.1 amps for 12,500 BTUs of heating. http://www.geinnovations.net/HSAC_Productline.html I'm looking at the HSAC-12H/C model. This type of AC uses a low-head rotary compressor that scales back its output and current draw based on need. It doesn't cycle like a normal piston compressor so no high current surges are required for start-up. Assuming it runs at full power continually, (an unlikely occurrence) and does not scale back current draw a 200ah bank of golf cart batteries would allow it to run over 8 hours (all night) before the batteries drained to 50% capacity. However with an inverter using considerable battery power, the larger 428ah Rolls bank would be ideal, especially in bouts of bad weather when there is incomplete solar charging. During the day, an elevated 1740 watt solar bank (25+ amps) should be enough to power the AC for several hours during the day as well as at night, without too much power management (reduction of consumption) in other areas.
Like your valid argument against the AIMs inverter, favoring the more durable Magnum - I'd rather pay 3 times as much for new 10 yr Rolls batteries than for ones with 35% less capacity and uncertain life expectancy.
Chip
