Mamiya Vintage Auto-lux 35 Camera W/ Sekor 48mm F2.8 Lens W/case & Strap "fixed input" Questions

I get an error 99 message (turn power switch to off then on again or re-install battery) I have a Canon XTI and a Quantaray 70-300mm lens. When ever I try to use the lens, I get an error 99 message ...

it doesn't charge Just got it and spent the night charging but still will only turn on if connected to the power. There is a circuit board either on the battery or the battery goes through and it ...