Goal Zero Yeti 400 AGM to LiFePO4 battery?

[smolsolar]

Is it possible to replace the Goal Zero Yeti 400 (lead acid) internal battery with a LiFePO4? If so, can someone recommend a battery?
I believe it has a PWM charge controller...

 

[solararray]

From my limited knowledge I would think this is not possible as the charge controller inside the GZ would be set up to charge a lead acid battery not a Lithium one. See here how lead acid chargers cannot charge lithium batteries: https://www.lithium-battery-factory.com/lead-acid-charger/.

However if you are inclined to tinker you could modify your GZ ---the person in the following linked modified their Yeti 1250 (which I believe normally takes a lead acid battery) to take an alternative battery, see here: https://diysolarforum.com/threads/eve-280ah-lfp-cells-in-a-goal-zero-yeti-1250.13600/

 

[Daedalus]

GZ dont advise the upgrade to LiFePo or Li-ion forthe AGM yeti's, but that said its never stopped the crazy minds on this forum, as the Yeti 1250 thread above has shown. There are some "drop-in" style LiFePo units that are designed to replace AGM cells, Bioenno do one that fits in the smaller yeti 150 (link in one of my posts)
The key if you go down the DIY Cell array or the drop-in path is the BMS. As long a the pack voltage matches the cut-off voltage of the AGM previously it should (in theory) be fine as the cell cannot be overvoltaged as the unit cuts off as it would with an AGM cell in its place.
The 400 takes an 33ah cell, i have seen the "drop-in" LiFePo for circa £150-300. it would massively help the transportability of the unit if it was lighter.