its a few yrs old, but a good laugh read on $8000 ($2kea)batteries for campers.
lithium iron phosphate (LiFePO4) batteries (http://caravanersforum.com/viewtopic.php?f=55&t=17543)
and you thought our electrical threads went off.
Price of lifepo4 batteries is coming down rapidly. Almost to the point where you'd consider them for camping duty soon. Should not be much more than twice AGM prices, I thought.
They can be repeated cycled to 80% DoD and are a lot lighter than equivalent AGMs. So arguably a better option if weight is an issue and they are frequently being cycled heavily.
See the Green Tech forum on Whirlpool for some more discussion (mainly discussion about going off-grid with solar using these batteries as a battery bank)
Quote from: chiselPrice of lifepo4 batteries is coming down rapidly. Almost to the point where you'd consider them for camping duty soon. Should not be much more than twice AGM prices, I thought.
http://www.alibaba.com/showroom/120ah-battery.html (http://www.alibaba.com/showroom/120ah-battery.html)
http://www.hollyhockbatteries.com.au/12V_100Ah_SSB_Li-ion_Deep_Cycle_Battery.html (http://www.hollyhockbatteries.com.au/12V_100Ah_SSB_Li-ion_Deep_Cycle_Battery.html) $1300ea
Edit:
some interesting figures here
http://www.allpurposebatteries.com.au/product_info.php?cPath=39&products_id=333 (http://www.allpurposebatteries.com.au/product_info.php?cPath=39&products_id=333)
Average Weight 15KG (appealing)
Cycle Life 3000-5000
Continuous Amp Draw 200AMPS
Couple of other options
http://elitepowersolutions.com/products/product_info.php?cPath=25&products_id=92 (http://elitepowersolutions.com/products/product_info.php?cPath=25&products_id=92) $620 for 100AH
http://www.evworks.com.au/index.php?product=BAT-LP12V90AH (http://www.evworks.com.au/index.php?product=BAT-LP12V90AH) $535 for 90AH
So about twice the AGM price, but you can safely use more of the quoted capacity and they are about half the weight of the AGMs.
As my batteries sit on the drawbar, the half weight is what interests me. Price just has to come down.
KB
Quote from: KingBillyAs my batteries sit on the drawbar, the half weight is what interests me. Price just has to come down.
get some from China! LOL!
I have been looking at these Lithium Iron jobbies and most if not all I looked at showed the C/5 rate not our C/20 rate - So a battery showing 110 aH COULD be at the C/5 rate and only 27.5 aH at the C/20 rate - Does that then become a problem for us camper folks - Drivesafe might know a bit more about that ... Steve
Quote from: Mandrake on December 12, 2012, 02:18:13 PM
I have been looking at these Lithium Iron jobbies and most if not all I looked at showed the C/5 rate not our C/20 rate - So a battery showing 110 aH COULD be at the C/5 rate and only 27.5 aH at the C/20 rate - Does that then become a problem for us camper folks - Drivesafe might know a bit more about that ... Steve
any subtitles for the numpties in the crowd like me?
Sorry Lost - I'm no battery person I'm not even sure if it makes any difference to the battery's capacity to discharge - hopefully Drive safe can enlighten us ..Mandrake
5 hour and 20 hour discharge rates in Amps!
I had to google it. i am a numpty too.
http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf (http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf)
I think Mandrake was alluding to the specification data provided by the battery maker and not being able to make comparisons with it to what we may currently use?
Quote from: Mandrake on December 12, 2012, 02:18:13 PM
I have been looking at these Lithium Iron jobbies and most if not all I looked at showed the C/5 rate not our C/20 rate - So a battery showing 110 aH COULD be at the C/5 rate and only 27.5 aH at the C/20 rate - Does that then become a problem for us camper folks - Drivesafe might know a bit more about that ... Steve
C5 capacity is usually lower than C20 capacity, for AGMs anyway.
http://www.fullriver.com/products/hgllist.htm (http://www.fullriver.com/products/hgllist.htm)
I'd be surprised if the C20 capacity for these Lithium jobs is not higher than stated capacity. But I'm no expert.