illuminated reticle eyepiece

[ripkirbyqld]

I currently have a University 12.5mm plossal illuminated eyepiece with the double crosshairs. The problem with it is that it uses an unusual battery which costs $33 if you can get them. Does anyone know of a similar eyepiece which uses a standard battery that won't cost a fortune.

[raymo]

You can get a 12.5mm Illuminated EP on ebay for $48. A Celestron one is
around $69.
raymo

[julianh72]

Do you know the voltage of the original battery? You can probably assemble something which will do the job by stacking a couple of "button" batteries together, and if necessary, pack out the extra length using alfoil or a small spring (such as in a retractable ballpoint pen), being careful to not short out against any metal on the sides of the battery receptacle. Eg wrap the circumference of your assembled battery with tape to hold it together, and to give it the right diameter.

Hope this helps!

[ausastronomer]

What is the battery model that it requires? There will be much cheaper suitable substitutes.

Cheers
John B

[dimithri86]

Try this experiment. Remove the illuminator, blu tack a red LED in and power it with any 3v button cell. This works perfect for me. I also soldered a switch in.

[ZeroID]

I wired mine up with an external battery, about 4.5v does it ( 3 AA's in a carrier ) Added a switch and a resistor to get it a bit dimmer. battery just sits on the top saddle of the scope. It will last forever, it gets infrequent use.
Those wee batteries are made from 'Unobtainium' I think.

[Shano592]

Rodney, what number is stamped on the positive side of the battery?

LR, AG series (such as LR44, AG13) are generally carbon batteries, and push 1.5 volts each.
CR series (such as CR2032) are generally lithium batteries, and push out 3 volts each.

For $33 per battery, they would have to be lithium, and I am betting there will be a cheaper alternative, too.