help disco 2 v8 thor no spark

hi every body thanks for the help finished fitting the rad oil coolers etc.
put the battery on just to check the spark, only just turned over but showed no spark.
before stripping did have a spark.
have checked the multi plugs at the coil pack they are fully home.
if the battery was dead would it just turn over but show no spark.
every thing as gone back double checked the coil packs before fitting made sure the ht leads where rght.
could it just be the fact the battery has had , will put on charge over night to see if that works.
have checked all the fuses in the engine bay all seems ok.
any thing else i might of missed , where does the coil packs get its single from.
tryed turning with the spark plugs out but just the selonoid clicking.

thanks

You'll need a good battery, we parallelled up a big 105AH sealed battery to nudge ours over.

If the battery is too low, the ECU won't fire the coils.

Peter