EQM35 power supply

[Felipe]

Hey guys,

totally newbie here, I just got my EQM35 mount and as it may have appear in an old post, doesn’t come with the power supply, I was wonder if any of you has some experience with what kind of power supply do I need for it?, is it possible to use one of those jump starter for cars?, the manual says that needs a 12V 3A to function, I’ve only found a few power tanks with that specs which are a bit expensive if I compare with a regular jump startEr with a different setting, same 12V but more Amp or les Amp.

does more Amp means it’s going to fry my mount?.

I’m base in New Zealand by the way, so if any kiwi out there would like to share some info, I would get them a beer!.

 

thanks guys!. And sorry if this thread was already opened!.

[David Smith]

The amp rating on the power supply is usually the maximum it can deliver at any time, so having a higher value than you require is not a problem. Having a lower value though is a problem and will not work.

[Felipe]

David, thanks so much mate!, i had the doubt with the amperage if it is safe to connect it to a higher Amp power supply.

 

thanks!.

[jonathan]

As far as a power tank goes, I would steer clear of those jump start things as they're designed to deliver very high amps for short bursts (for starting a typical family car), they are not ideal for running a telescope mount over several hours.  Typically a lead acid car battery or jump start battery will degrade quickly if discharged below 50%, they are designed to be kept charged at all times.  You can use a 12v lead acid battery with a mount so long as you are careful not to discharge it below 50% and charge it as soon as possible after use, and remember to charge it periodically when not in use (any car battery charger should do the job, but a smart charger will help maintain the battery better).

A much better and more robust battery for the job is what's commonly called a leisure battery, or one that would typically be found inside a caravan or motorhome for running the electrics (not the one for running the engine), they are designed to give power through their entire capacity so it's safe to discharge them well below 50% without any harm coming to the battery.  You can get large or small versions, so long as it's designated as a leisure battery it should be fine.  Then all you need is the appropriate cable (assuming you have the original power cable that goes to a cigar type plug) - buy or make a small adaptor cable to go from the battery with an auto / cigar socket on the end, an inline fuse on one of the wires is required for safety (otherwise, if there's a short circuit then your wiring could heat up very quickly and catch fire, cause burns, etc).  All the parts for this should be available from an auto parts shop, be sure to use 3A wiring too.  The cigar type auto plugs usually have a fuse inside them, this covers the cable it's attached to but it wouldn't necessarily cover the battery adaptor cable it plugs into.

I've built various cables for my Skywatcher mounts which are all powered by lead acid or leisure batteries.  I have a Yuasa 6v lead acid battery which works very well with my CG-4 mount, and a Yuasa 12v which does a fine job with my NEQ6 Pro mount.  Note that these Yuasa batteries are more typically designed for embedded applications (e.g. UPS or alarm systems) so they have spade terminals rather than standard round terminals as found on a car battery, if soldering and making stuff is not your bag then perhaps stick to the bigger (heavier) lead acid / leisure battery with pre-made adaptor cable.

 

Edited June 4, 2020 by jonathan

[Felipe]

Hey Jonathan, that’s really helpful info, I’ve read in a different forum that leisure batteries are no good for powering a mount due to a fast degradation of the battery, I guess all depends on the maintenance of it, finally I’ve got a  power tank with the same specks of a Celestron power tank or any other Telescope brand, I’ll see how it goes with that one for now, is winter here where I am so, I haven’t got may clear skies to test it out, thanks for the answer man!.