Below that voltage the cells can be damaged and might ... give LiPo a try and have a look at [Andy]’s LiPo battery safety issues post, also on Hackaday.io. For a broader LiPo overview, see ...

They tend to have a very low operating voltage, and due to ... albeit slowly, but LiPo batteries will definitely not be suitable. Other battery chemistries are available, such as Lithium Iron ...