Old UPS battery for solar setup

Published Date 3/10/12 10:16 PM

Am testing out a load of solar gear in my back garden, have a old 17AH lead acid battery from a UPS, trying to find out if it will hold a charge. You have to keep batteries topped up with power otherwise they deteriorate over time.

UPDATE: it did not hold a charge I had to go out and buy a new battery from maplins, which works fine.

UPDATE2: I damaged the new battery so have to replace that, by charging it with out a charge controller, was using a volt meter to keep an eye on its level manually, but it only took one time forgetting and leaving it out in the sun to damage the battery – get a charge controller as human beings are prone to fail (:

Why indymedia has the site is untrusted message

Published Date 3/8/12 9:13 PM

Have you always wondered why IMC sites have the horrendous go away this site is dangerous message in most web browsers. Its because of this:

—– START Explanation from ****, **** —–

Security is a two-way street. When I go to a web site I have to prove to the web site that it’s really me before the web site gives me access to anything private or restricted (such as access to my email). The most common way that is done is via a login in which I provide a username and a password. Because I supply the correct password, the server knows it really is me, because I’m the only one who knows my password.

But how do I know that the server I’m going to really is the server I want to go to? Just because I type https://docs.indymedia.org/ into my browser, doesn’t mean that the server really is the Indymedia server that I think it is. Any number of things can happen via the Internet between my computer and the server I’m connecting to that might fool my computer into thinking I’m connecting to docs.indymedia.org when in fact I’m connecting to someone else’s server specifically setup to look like the Indymedia server. If that were to happen, I might type in my username and password on this stranger’s server that is acting like docs.indymedia.org, essentially handing over my identity to a stranger.

The purpose of security certificates is to ensure that the site I’m connecting to really is the one run by Indymedia.

Unfortunately, the technology for setting up this system is fundamentally flawed. It works like this:

* most major browsers, even free/open source ones like Firefox, are pre-configured to trust a pre-defined set of for-profit corporations to verify the identity of all web sites on the Internet.

* web site maintainers are expected to pay $75 or so to these corporations in exchange for a digital certificate verifying that we are who we say we are.

* once this digital certificate is installed on the web server, browsers will access the secure web site without any errors.

If you don’t pay $75 for the certificate, then most people will get a security error. There’s a word for a setup like this. It’s called a “racket.”

Rather than play this racket, Indymedia uses cacert.org to sign it’s security certificates. cacert is a nonprofit organization that signs certificates for free. cacert is not pre-installed on most browsers, however, you can install it by following the directions here: http://wiki.cacert.org/BrowserClients If you install the cacert certificate, your browser will automatically trust all indymedia web sites that have been signed by cacert, so you will no longer get any error messages when you access them. However, in addition, your browser will trust *all* web sites signed by cacert (which could be a good thing or a bad thing depending on how cautious you are).

—– END Explanation —–

So, this addresses the “problem” that many of us experienced for many years. Its actually a nice opportunity for political education!

However, my understanding is that since last summer, even this explanation won’t completely address the problem with the global site… I consulted with a few people offlist before responding to this because I didn’t want to add to the confusion. It appears that our security certificate for the global server has explicitly been revoked – see: https://lists.indymedia.org/pipermail/imc-tech/2011-June/0602-g4.html It appears that this may have taken place in conjunction with the conflicts in the UK group. So, even if you import the cacert certificate to your browser (following the instructions below), you may still get a problem connecting to the site. I’m not sure if this means that we can never again have a viable certificate through cacert or whether we have to purchase one from the racket that **** refers to?

Hope this is helpful, ****

Turning off the comments

Published Date 2/28/12 1:34 PM

This is a video response to Dave Winer’s post on Scripting News about why he has turned off commenting on his blog.

Winer was using the comment platform Disqus and discussed with the developers to have some options implemented. He got frustrated at the end when he realised he could never get from them the right functionalities and turned off the comments.

At visionOntv we have ideas about how to deal with comments and we’ll give practical proposals very soon in the videos to come.

Meanwhile we’d like to hear from you on this subject. Is it still a blog if no comments are allowed? Where is the conversation and debate then supposed to happen? What solutions have you tried on your blogs? Are you using an external comment platform or any form of moderation? And do you have a specific strategy for Youtube comments to bypass the daily abuse, auto-promotion and trolling? 

Workshop on Solar Vagabonds at London Hackspace

Published Date 2/15/12 12:57 PM

The solar vagabond. Move your office to a beach or mountain-top far away from the power lines and keep connected. I have been testing and working with solar tech for years and will do a presentation of new and old toys.  With advice on which gear to buy/not buy for your laptop/mobile. Feel free to bring your own gear! 

The exampes I give here are from two of my less successful solar experdions. 

Fri 17th February 6.30pm

This is 32W soild panel with 2nd generation lithium battery

This was a more robust solution, but it had many problems, the second generation battery would not pass throug power while charging thus was very limited in use. And the set-up was 3x as heavy as the flexible panel limiting its use to more long term set-ups rather than vagabonding. This set-up hasn’t been fully tested yet.

Equipment: Thinkpad T410 and Panasonic 900 AVHCh

Not used yet due to carrying weight issues.

0.2w USB 4xNiMH phone charger

A very cheap, 10 and 10 for the battery’s. This worked, but it would take 2-3 days of sun to power the phone for one charge, and the NiMH battery’s had a high self discharge rate thus would lose power as fast as they gained it on low sun days. This kit kinda worked, so I bought a second one, I use it mostly as a USB backup charger for my citizen journalism work – with the recharging coming from the laptop USB not the solar panels. On the Greek island trip I would use a car lighter USB charger to recharge the NiMH battery pack for later phone charging, with the solar part being marginally useful.

HTC Desire Z and Nokia 95B

Used on wild camping trip to Greek island beach for one month.