Choosing the right powerpack

[mattias]

Planning to buy a suitable powersource for my field trips with my soon to be EQ6.

I would like to provide enough power for the following to be used simultaneously:

EQ6

Canon EOS 500D

Guide camera

and maybe my MacBook Pro 15".

Here in sweden we have a multiple of powerpacks/mobile starters to choose from, but I'm curious to hear from you how many Amp hours is needed generally? Let's say with 2 hours of photographing etc.

The bigger pack, the heavier, and the EQ6 with Meade 127mm is already a heavy bulk to carry :-)

Would be really happy to get some input here.

[dmahon]

Given the Mac's own battery and the Canon's own battery will last 2 hours anyway, a standard 17Ah pack should cover 2 hours of the EQ6 quite easily. It will probably just cope with anti-dew for the scope and guidescope as well for that amount of time.

[NickK]

I went for the big option at 100Ah (Bosch S5, 21Kg!), figuring with my simplistic view of electrical stuff:

2 amps for the EQ6 Synscan

1-2 amps per camera (two for imaging)

2 amps per dew heater strip (I have two)

300W Inverter (although MBP powerblock takes 86W) supposedly 8A @ 12V.

Total 18 amps

Now if you're out imaging for 4-6 hours, that's 18*6 = 108 Ah. Only thing is that 100Ah with an 8A charger results in a 25 hour charge!

The danger is that the battery can deliver 820 amps for car starting.. so it's vital to prevent shorting etc!

Those are conservative max figures and I'd expect that the power consumption would be less and therefore the battery wouldn't be entirely used (added benefit is using spare capacity to heat you!).

[mattias]

I went for the big option at 100Ah (Bosch S5, 21Kg!), figuring with my simplistic view of electrical stuff:

2 amps for the EQ6 Synscan

1-2 amps per camera (two for imaging)

2 amps per dew heater strip (I have two)

300W Inverter (although MBP powerblock takes 86W) supposedly 8A @ 12V.

Total 18 amps

Now if you're out imaging for 4-6 hours, that's 18*6 = 108 Ah. Only thing is that 100Ah with an 8A charger results in a 25 hour charge!

The danger is that the battery can deliver 820 amps for car starting.. so it's vital to prevent shorting etc!

Those are conservative max figures and I'd expect that the power consumption would be less and therefore the battery wouldn't be entirely used (added benefit is using spare capacity to heat you!).

Or I could just bring the whole car

[mattias]

Thanks!

I think I'll go for the 17Ah right now. Too much to carry otherwise.

Keeping the car close in case

:-)

[Key]

Or I could just bring the whole car

Ha ha

[michael.h.f.wilkinson]

Or I could just bring the whole car

or a diesel powered generator

[AndyH]

If funds permit, get the best quality power pack you can. I've had about 4 over the years and 2 had to be sent to the recycling after about a month. Of the other 2, one is perfect and the other holds only a 50% charge.

A bigger outlay at the time may be a bit disheartning, but it will pay off in the long term.

Andy.

[Key]

If funds permit, get the best quality power pack you can. I've had about 4 over the years and 2 had to be sent to the recycling after about a month. Of the other 2, one is perfect and the other holds only a 50% charge.

A bigger outlay at the time may be a bit disheartning, but it will pay off in the long term.

Andy.

Go on then: what make/model is the "perfect" one?

[Key]

Originally Posted by AndyH

If funds permit, get the best quality power pack you can. I've had about 4 over the years and 2 had to be sent to the recycling after about a month. Of the other 2, one is perfect and the other holds only a 50% charge.

A bigger outlay at the time may be a bit disheartning, but it will pay off in the long term.

Andy.

Go on then: what make/model is the "perfect" one?

@AndyH: You can tell me; I won't tell anyone else!

[AndyH]

Perfect one ?

To be honest I don't know as I still have 1.5 maplin ones still working. Once they die I'll spend some dosh on a good quality one. Will need to do some research, but I do remember a vendor at Kielder one year having a compact, top knotch one. I won't get another cheapo one again.

Andy.

[michael.h.f.wilkinson]

I just ordered a Skywatcher 17Ah powertank. It has a built-in 9V supply which I need for my GP mount. I worked out that I could buy the pack for 4-5 sets of batteries, each of which lasts 3 sessions. At the current rate the pack is economical after at most two months. I will let you know what I think of the thing when it arrives.

[Star Gazer]

I was thinking about one of these:

Amazon.co.uk: Sky Watcher 17Ah Rechargeable Power Tank - Automotive: Car & Motorbike

But for £20-30 more, doesn't this make much more sense?

Ring Automotive RPP210 12V 40ah Power Pack Complete with 300W Inverter: Amazon.co.uk: Car & Motorbike

At least with the Ring I could charge my laptop as well as power my mount and camera?