Deep cycling lead acid ? I've watched overall battery tech soar, that do surprises me Nice thing is if you can obtain them dry they would store forever on the shelf (spares for the Z Apoc) Any good online sources?
InterState Battery in Everett, WA is where I get mine.... Deep Cycle is nothing more that a Battery with Heavy Plates, as opposed to a Starting Battery, that has Lighter Plates, but more sintered Surface Area, for more Cranking Amps....
Lithium Iron Phosphate batteries are up-and-coming. They are still more expensive than Lead, but the charging characteristics are much better - they take full current until they are full so they store power more rapidly - and they are good for more cycles - and they can be fully discharged so you can use a smaller bank. They are becoming popular on high-end yachts. Prices will come down. I expect my next bank will not be lead (in a few years).
Going off grid ASAP when the castle is finished, so maybe 2 years max. I'm assuming the two types are not interchangeable in the same system?
I don't think the two are interchangeable within the battery bank - cell voltages are different, but there are LiFeP batteries with similar nominal voltage to 12V lead batteries, so one could change the bank at a later date and retain the same equipment for charging and inverting and so forth.
Spot on Kilo/Golf four, Juliet/X-ray/Tango... Not only are the cell voltages different, the rates at which the cells give up energy and recharge are completely different. Having mixed batteries in an array is asking for problems. Like having automotive cranking batteries in the array with Deep Cycle RV batteries, there are always issues. Even like batteries with different internal resistances causes problems. Old batteries of the exact same manufacture, type, voltage, and rated ampere hour rating but with different discharge rates (the length of time they will provide optimum output to a fixed load during discharge) can cause premature array failure. You can't just set it and forget it... Decent web page here.. http://www.wholesalesolar.com/Information-SolarFolder/battery.maintenance.html And a good PDF here .. http://www.poweringhealth.org/Pubs/Guyana_Solar_PV_Systems_Maintenance_Guide.pdf
