FWIU, lithium-ion batteries (in the Optimus Elite) should never be charged overnight. Once it's fully charged, yet continuing to charge, will have a negative effect on the battery life/performance.
It would be better to time how long it takes on average to charge from x% to full. Then when you go to charge from that % on a regular basis, check back on the phone status to see when it hits 100%. A charge really doesn't take that long with this phone.
If you are concerned about burning some battery on your already charged phone while you are asleep, you can disable data/blue tooth/wireless.
But partial charges on lithium-ion batteries can be done without issue.