A while back I purchased 8 Eneloop AA rechargeable batteries to power my new Nexstar 6SE. Impressed by their value and the possibility of 2100 charge cycles, I brushed off and, for the most part, ignored the warning of Kenny at OC Telescope who cautioned me that they may not be entirely suitable to properly drive the telescope. Well, much to my disappointment, I too experienced the frustrations of the runaway mount, the grinding motors straining under insufficient voltage, and the missed gotos. This has been described by many users here*.
And despite coming across the occasional post or two praising their use**, I could never get them to work properly even after several repeated attempts.
Many simply bought an external battery pack and never looked back. Well, I discovered, to my pleasant surprise, that bundled with the Revolution Imager*** that came with the telescope was a lithium ion battery that appeared to power mount with ease. Problem solved, right? Well, sort of... For some reason, I wasn't satisfied with such an easy fix, after all I still had 8 batteries that -should have- worked.
After a bit more poking around, I came across a DC/DC boost converter that seemed like it would be just the right tool for the job:
After a few minutes of fiddling with a tiny little screwdriver to adjust the voltage pot. I think I have chanced upon telescope nirvana. I dialed in the unit to around 13 volts (I don't have a good reason why I chose this number, it just has a nice ring to it), hooked everything up and ..... Presto!!! - the unit powered up, spun freely and quickly in all directions, and life has been good ever since (at least for all of 20 minutes since I decided I should quickly hop on here and share such exciting news).
I will close with just a few pictures from this experiment and final observations:
1) Sure enough the battery back as it sits in the telescope stands ready at 10V (confirming that each individual AA cell doesn't really push more than ~ 1.2 Volts)
2) Oddly enough the generic Lithium Ion Battery pack only put out 1 additional volt but the mount appeared to have no trouble running at 11 volts where it really struggled at 10 !
3) A picture of the step-up converter
4) And the final result - a nice boost of 3 volts bringing the output of the Eneloop rechargeables up to 13 volts !
Lastly, I have also been able to place the step-up converter in between the Lithium Ion battery and the mount bringing it too up to 13 volts, but so far it does not seem to have made any difference.
*** which has turned out to be a wonderfully fun tool but that is a subject for another day.
Edited by Justin Ducote, 17 September 2020 - 07:09 AM.