Interesting Battery Discussion

[Bird]

its a few yrs old, but a good laugh read on $8000  ($2kea)batteries for campers.

lithium iron phosphate (LiFePO4) batteries

and you thought our electrical threads went off.

[chisel]

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)

[Bird]

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.

http://www.alibaba.com/showroom/120ah-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

Average Weight 15KG (appealing)
Cycle Life 3000-5000
Continuous Amp Draw 200AMPS

[chisel]

Couple of other options
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  $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.

[KingBilly]

As my batteries sit on the drawbar, the half weight is what interests me.  Price just has to come down.

KB

[Bird]

As my batteries sit on the drawbar, the half weight is what interests me.  Price just has to come down.

get some from China! LOL!

[Mandrake]

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

[Bird]

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?

[Mandrake]

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

[Mace]

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

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?

[chisel]

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

I'd be surprised if the C20 capacity for these Lithium jobs is not higher than stated capacity.  But I'm no expert.