Choosing a battery.

[paulbacca]

Hi All,

I've recently bought a 10" Skyliner dob with goto. I've been looking at batteries and there are lots to choose from. However I seem to lack the one piece of critical information that I a need to make a decision.

Exactly how many amps does a Skyliner 250p pull?

I already know from my welcome that there are other 250p users here. What solutions are you using and typically how much time do you get from your batteries? I've heard that deep cycle gel batteries are good. These are very expensive though.

Thanks

Paul

[Bizibilder]

Deep cycle or leisure batteries are expensive to buy but, with proper care (and a good charger/conditioner) will last for years. A mount will draw around 2A when slewing (assuming the scope is well balanced, as it should be) and around 1A when tracking. These figures are for EQ mounts but I suspect the motors/currents will be about the same for a Dob.

To calculate what you need: 2Amps for, say, five hours uses 10Ah (amp hours). Generally we double that figure as it is not a good idea to completely discharge your battery - so 20Ah capacity will be enough for your scope only. Often we need to add various other bits of kit like cameras and dew heaters and this will soon add up! The smallest leisure batteries (designed for caravans and boats) are around 60Ah and one of these would be ideal.

[faulksy]

or you could use 12v alarm panel battaries these are around 10a/h you can put them in parrellel and house them in a 12" plastic toolbox

[NotSoSuperNova]

Forgive my ignorance here but how do you actually connect these batteries to your mount?

[paulbacca]

Thanks. That's very useful.

I'm assuming you made your own cable/connectors with a switch or a fused switch just in case?

Paul

[paulbacca]

Connecting to a my mount. You would need a 2.1mm connector soldered to a couple of battery connectors. Very cheap to purchase from Maplin or ebay.

[faulksy]

Forgive my ignorance here but how do you actually connect these batteries to your mount?

basicaly just run a fused supply lead from your battaries/power tank to a 2.1 pin or what ever you adaptor is and plug it into your mount.

[DOBBY]

I use one of these for a 400p... http://www.amazon.co.uk/dp/B0045TTBAM/ref=asc_df_B0045TTBAM12666177?smid=AN686FK1SRNI7&tag=shoppingmp20862-21&linkCode=asn&creative=22218&creativeASIN=B0045TTBAM

it sits on the turntable at the front under the eyepiece holders & came with leads...