Using the Lithiums in low temps is not really the problem......charging them is!
I had a very long conversation with AM Solar today, and the batteries that they are showing on their web site will be built and warranted by AM Solar, including the battery cell balancing electronics and battery monitoring equipment. I will offer this abridged version of the main points of my conversation from today.
100 amp/hour basic block: 9-3/4 long, 5-3/4 wide, 10-1/2 high (these are working dimensions)
28 lbs vs. 65 lbs for a Lifeline group 27 100 amp/hour AGM
Larger batteries can be configured in many shapes, allowing them to be placed in a wider assortment of places.
The basic 100 amp/hour battery block is $1300, and this includes the cell balancing electronics and BMS (battery monitor system). Each additional 100 amp/hour block will cost approx. $700, as you only need one BMS per battery, regardless of size.
The BMS is required for the warranty to apply (3 year full replacement/5 year pro-rate replacement) as it protects the batteries from being over drawn and/or overcharged. This is EXTREMELY IMPORTANT to the long life of these batteries. Special charging requirements are necessary, as these batteries MUST be bulk charged at a constant voltage of 14.2VDC measured at the battery terminals, and float charged at 13.2VDC.
These will not be properly charged by any converter currently available, and must be charged when on-grid by a Magnum inverter/charger or similar fully adjustable power factor corrected charging system. Also, any quality solar charge controller that allows for individual voltage set points and charge duration for bulk and float will work well also. Temperature compensation is not used
in these batteries
As it turns out.........the idea of Yttrium as an additive to the LiFePO-4 formula to allow for enhanced use and charging below freezing was a SCAM
with no scientific or experimental backing or data. In fact, it was a ruse used by one company to try to evade a distribution contract they had signed with another for exclusive North American distribution rights to their batteries by saying that they were a different formulation. ALL SMOKE AND MIRRORS!!!!!! This LiFePO-4 formula is the best presently available.
There is significant danger of ruining these batteries when charging them at temperatures below 32ºF. Use at this temperature is not recommended but will not degrade the batteries, but charging WILL. The lithium is in a paste form and not in a mat like an AGM and will plate out to the anode and/or cathode (copper and aluminum) when charged below freezing, which will seriously degrade the performance of the batteries.
AM Solar is working on a thermostatically controlled mat that will keep these batteries above freezing at below 32ºF ambient temps. There is also NO DANGER with placing these batteries inside an RV, as they are incapable
Another caution: They MUST be used in the upright position....similar to a flooded lead acid type battery, as the lithium paste can migrate from covering the plated in any other orientation.
Shipping is still 'under construction' as these are classified as hazardous materials and require special handling. AM Solar is working with UPS national accounts to resolve any issues they may have with these new batteries.
Stay tuned for any late breaking developments!