Unit came out a storage clean out and I purchased a charger and the unit will not charge. I believe I have the correct charger and when I plug in and hit the power button the unit beeps and all 4 lights blink but doesn't seem to want to charge. May need a new battery? Unit is for parts or repair and has not been tested and will not charge with the included charger I got for the unit. Unit has some scuffs & scratches - see pics.