Hi All
Thanks for the info re the 12v Li-Po’s. They do not appear to have a balance plug fitted, could cause a problem with charging, also not sure what the discharge current is, 1C would make them 6.8Ah, Ok for an 817, but may stuggle a bit with the 857. I have e-mailed the seller to ask the questions and will report back when they let me know.
2 terminal lithium batteries intended for use with a dumb charger have the protection and balancing circuitry integrated in the battery. I’m sure that must be the case here.