There are less expensive batteries ($45 - $50 per 8000mah would require < $60 charger) with comparable output with a life of over 200 recharges. What scares the He22 out of me is these things are in some cases keeping you alive.  What happens if the battery goes dead in the middle of the night?  If there was a alarm (don’t know how loud they are)  that went off when the battery needed to be changed would it wake you up so you could change it. 
The biolite produces about 2 watts @ 5 volts for recharging a cell phone.  If you could convert that 2 watts @ 5 volts to 2 watts @ 12 volts you could use it to charge one of the batteries we are discussing in about 48 hours. 
There are some solar collectors that may work to run the charger mentioned above and charge one of these batteries in a few hours.