[mythtv-users] Netbook as low-power combined back-end / front-end?

[Michael Watson]

On 28/08/2012 4:44 PM, Simon Hobson wrote:
> rsh1k wrote:
>
>> But the
>> battery is also a pretty big advantage for the netbook.  I think the
>> last UPS I had on my Mythbox was down to an estimated 12 minutes of
>> runtime after about a year of use... whereas, a netbook with a few
>> hours of battery would have no problem if I had to unplug it during a
>> lightning storm or that sort of thing.
>
> Don't count on the battery being any use. It varies a lot between 
> battery types and quality of charge management, but some in particular 
> really don't like not being used regularly. So you may find that after 
> a few months of being sat there plugged into power, the battery is dead.
>
> On the other hand, if you pick a system that runs off 12V (as some of 
> the ION boards do, then in principal you should be able to just hook 
> this up to a 12V lead acid battery and use a 13.8V supply/battery 
> charger instead of going with a full UPS. Also, for things like the 
> mini ITX boards, there are PSUs designed for in-car use that run from 
> a battery and will auto-shutdown on low battery etc.
Not exactly an energy efficient way of doing it, unless your battery 
charger is smart enough to stop charging when battery is fully charged, 
or not charged at all when battery is charged and directly power the 
PC.  Could be super efficient if you used a solar charger to keep 
battery charged, and charge generated was enough to power the machine 
during non daylight hours.

>
> Lastly, what sort of climate are you in ? Or more importantly, what 
> sort of temperatures does your UPS live in ? The VRLA (Vale Regulated 
> Lead Acid) batteries they use really don't like heat and despite 
> what's claimed about them they will dry out. If the batteries are 
> still running, it may be worth prising the cover off to get at the 
> rubber caps on the cells, and putting a tiny amount of distilled water 
> in - only a couple of ml, a small syringe is good for that - to 
> rehydrate them and see if they improve.
>