Laptops and Batteries

[Delphine]

Hello again

A couple more questions:

I gather that I need at least 3 hours battery capacity on my laptop but my laptop has only half an hour!!  I noticed at the DSC that some of you had batteries to connect your laptops into. 
What type of batteries are these? 
Are they heavy to carry? 
Are they expensive? 
How long do they last? 

I have another question but can't remember what it is at the moment!

Cheers
Delphine

 

[Mike]

Delphine,

I use an 110Ah battery which will power my laptop for probably a whole day continuously. I also have a smaller 85Ah battery. The 85Ah battery can be purchased for around £35 and the 110Ah for around £55.

[Delphine]

Thanks Mike - that sounds perfect and not too expensive either.

Rick - I didn't think it was a new topic as the laptop is for running the webcam software.  But I see your point!

[Ian]

you'll need longer than 30 minutes.

We all tend to use either car batteries or leisure batteries. Their distinguishing features are being good for a nights imaging, reasonably priced and weighing about the same as a small elephant.

Fay uses smaller batteries than Mike, but has more of them, but they are easier to carry. You'll need a car battery charger and an adaptor suitable for your laptop. There are two approaches to this, either buy a small inverter (150W or so) and use the mains power brick or buy one of these http://www.maplin.co.uk/Module.aspx?ModuleNo=36836&criteria=laptop%20power&doy=17m10 which should be more efficient so requiring a smaller battery for the same life.

Last DSC, I used a single 110Ah battery which drove my scope and laptop for several hours both nights without a recharge, so a single 55Ah battery should do you for quite a while (you can simply add and subtract Ah (amp-hour) ratings)

just one more point, when you're sizing batteries, make sure you have a reasonable amount of spare capacity, it does car batteries no good at all running them completely flat, leisure batteries are much more resilient to that sort of treatment. Also make sure you store them fully charged, so get them on charge as soon as you can after using them.

[Delphine]

Thanks for all the advice Ian.  I will now go and digest it.   I suspect I should do what Fay does and have several small batteries if that is not too expensive.