That's the file, there's one in MO & the stock data files. The entry in both the stock SH5 file and the MO file are the same (presumably because I'm running the mod):
[SpecialAbility 7]
ID=Ability-Reduce-Battery-Recharge
NameDisplayable=Ability-Reduce-Battery-Recharge-Name
Description=Ability-Reduce-Battery-Recharge-Description, Ability-Reduce-Battery-Recharge-Description, Ability-Reduce-Battery-Recharge-Description, Ability-Reduce-Battery-Recharge-Description, Ability-Reduce-Battery-Recharge-Description
Levels= 1
AbilityType=BatteryRecharge ;reduces battery recharge time (in percents)
AbilityValue= 0
PointsRequirement= 0
AbilityRequirements= 0
LevelUpTree= 2
MoraleCost= 0
PointsCost= 1000
AbylityActsIn= ALL
Duration=3600
Cooldown=86400
So not sure what 'Levelup Tree' is, but looks like it costs 1000 points!

I assume that's the number to alter anyway?
If I alter these files, will I have to remove and re-add MO to the mod list in order for it to work? Last time I messed with the mod list too much it wrecked my campaign and I'm a bit wary!
EDIT: just tried RTB's Morale Mod, but it CTDs any existing saves, so thats not an option.
Double Edit: Yup, altering that file (found in data/UPCDataGE/UPC Crew Data) to 10 sets the in-game cost to 10 as expected. Assume it'll revert if I uninstall MO but it's an easy tweak, thanks for the pointer TDW. Will probably go back through that list and check the others, as I think there are a few more that costs 1000 points.