I got a refund for the 60Ah NMC (Nickel Manganese Cobalt) lithium battery and ordered the 40Ah Lifepo4 with a 10% off voucher that Ebay happened to have available. It sounds like a good thing but time will tell.
https://www.ebay.com.au/itm/12V-40AH...g/142905405468
The 38Ah lead acid gel cell I have is very heavy and only lasts about 3 hours with dew heaters running. I've also got a 17Ah jump start and between the two batteries I get maybe 4 hours imaging time with heaters set fairly low.