I have a barely used transponder for sale that I bought brand new and never registered with MYLAPS. I've kept it like new and I just checked it this weekend and its held charge like it was new. Four blinks for a full 24 hours at least. I charged it Saturday evening and it's still blinking twice right now sitting here looking at it!! Asking $450.00 with all charging stuff, wall and car, bike mounting kit, and stickers!! Thank you, Scott