Key Battery Replacement Failed?

Just a note on key remote battery changing.  This is for the simple Mk1 remote that just unlocks doors. I followed the guides in here (and elsewhere on line) but after re-assembly, the key remote worked for a day or two then failed.  I tried several times with same result.  Finally, on a whim, I used a small screwdriver to gently part a little the two(squeezed together) sides of each of the two (looped) metal contacts on the crazy notion that perhaps they each needed to contact something on both sides when they went into slots on re-assembly.  And unless it was a co-incidence, that's right, because the fobs working fine now for 3 months.