My battery ate my mirror!

Just read Dave's review on the 28"...Yikes! I'd never heard of battery outgassing affecting the coatings on a mirror. Does any one out there know anything about this?
Larry Seguin
Taos, New Mexico

Hi Larry,
No, I had never heard of outgassing affecting the mirror coatings, but it's good to know.

This past weekend I had the opportunity to observe a bit with Eric at Lake Hudson RA in SE Michigan. He had just recieved the 28" f4 w/Kennedy mirror back from Dave B. after his review of it. All I can say is WOW. The seeing was very good for Michigan and the view of M13 through a bino viewer was incredible. M51 showed gobs of detail, and the Swan Nebula looked like a photograph. I hardy looked through my 10" dob at all as I also had my first look through a Starmaster 18" that a friend just bought. Eric is making me a mirror cell for my first ATM project, a 14.5" f4.3 and I kept shaking my head asking myself if 14.5" will be enough. :S At least it'll be easier to move and I won't have any long lines at starparties. 8)

I would suggest that sealed batteries would be safe but should be removed when being recharged. I always remove mine during charging. Discharging should not cause much outgassing of a sealed battery from what I have read. There are many makers of scopes that install the batteries in the rocker box and I have not heard any tales of damage.
However, if the mirror is very close to the batttery and there is not good ventilation, I would say, better to have the battery outside the rocker box. I have recently removed my batteries from the rocker box and mount them outside. Here is how I handled the problem. It just hangs on the lip of the box, the plate is glued to the battery and has felt where it hooks over and rests against the wood.

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