is balance board connected correctly ??
other than that watch this vid - ALL OF IT !!!
(OK first 1:30 mins the bloke is dicking about a bit but watch the rest for sure)
and CAREFULLY start charging to get it above the low voltage mark
then it should attempt to work ok
note your charger seems to be similar to B6 type
but this is best I can offer - be careful and charge in a safe place
on worktop in garage or deffo not on floor/bed etc....
hope this works - be careful
I know there is a way to force charge lipo's for when some chargers/lipo's only take 90% charge
and people top up to near the max 4.2v per cell
BUT that is for people who know what they are doing
What your lipo's have is a charge below its limit and in vid it will force some juice into them
Then it should no longer get error and hopefully charge up normally on lipo program
Other than than it is gonna be a case of getting dean-s.tamiya so you can use yours
(or fit deans to yours but only if you can solder and cut+solder ONE WIRE AT A TIME)