Topic: Building a power source - input needed

[bgreen]

Hey folks,

I work for a fella that is an absolute wiz with electronics. He's offered to do some work for me. I've used him in the past for other stuff and I am always absolutely ecstatic.

What I want to do is build a nice power supply specifically aimed at taping.

What I'm looking at doing is having 2 large rechargable battery packs(suggestions). I want to make the voltage and amperage selectable at the output so it can be used with different equipment, and it will include up to four outputs, all with universal connector options. He's working out the logistics of filtering the output power, having a small LED meter that will show you what for charge is left(this will be push button, not on all the time). and it will be recharble simply by plugging the unit in.

Basically what I would like is a little input from the experts here on what I should and shouldn't be putting emphasis on for this. Any input? I wanna make a unit that will last a long time for festi's ect. I may be way off base on what I want to do here so feel free to tell me I'm stupid.

[Neilyboy]

Sounds like an awesome idea man! I wish you the best of luck with this! I will be following along with your progress for sure!

Neil

[sunjan]

Interesting, T+ for the initiative!

So if we are looking at the specs, should it be able to power a rig for one festival day (assuming overnight charging inbetween), or a multi-day festival without charging?
In my case, I'd be satisfied with one day runtime (6-7 hrs), and less weight to carry.

Also, are you planning for more than one simultaneous outlet with different voltage (like the 5V/9V box for JB3+UA-5)? Or just one outlet at a time?

[bgreen]

It looks like we are going to go with the assumption that overnight charging is attainable. We may go with bigger cells down the line.

There will be up to 4 outlets avaialble. You will dial in the volts and amps you need for each unit your powering and lock it in before the plug will work.

[sunjan]

You will dial in the volts and amps you need for each unit your powering and lock it in before the plug will work.

Correct me if I'm wrong, but my understanding is that you don't actually set the current (amps), as it is a function of the draw. Basically, it should suffice to regulate the voltage of each outlet, and whatever device connected will then just consume as many amps as needed (provided the battery pack can provide them).

[bgreen]

I'm just the Idea guy 

The fella working the building of the board and setting out the circuits will have that all taken care off, basically you will be abel to set what you need. I believe were getting started here very very soon. If anyone has any other input on what I should pay special attention too, please do comment. I like projects and tend to pick ones I have limited knowledge in 

[jerryfreak]

sounds like a cool project but just buying two tekkeons is infinitely more practical

[sunjan]

sounds like a cool project but just buying two tekkeons is infinitely more practical

Jerryfreak has a point.
Don't know in which segment you intend to market the power source, but the economies of scale will be working against you, when you're competing with mass-manufactured battery packs from Asia.

You'll most likely end up on a much higher price point (look at guysonics super-exclusive $$$ battery bays   ).
Is the prospective taper willing to pay for the convenience of having more customized gear?

[bgreen]

This is more of a personal satisfaction thing for me, I'm not really looking to make  $ on it. Just something to tinker with. My ultimate DIY battery box so to speak. I'm sure if anyone is interested, I can make more. I really just want it for me though and was looking for input so I don't do it 10 times.

I think I can come in under two tekkeons price though 

[H₂O]

You need to be as cheap and as effiecent as possible to make this worth it. 

Think of EcoCharge (great products for years and now no where to be seen) - $200 battery systems don't cut it anymore as China is in the picture.

If you can get a $50 switching power supply (minus the batteries) with multiple outputs and gen almost no heat and you may have something.

For $130 shipped you can get a very high quality Tekkeon 3450 with 1 5V output and 1 variable output (5-19V) and rated at 50Wh - as a comparison.

[taperj]

one thing I've never seen on portable power supplys are hot swap cells, that would be the coolest.
i.e. - if you built it out of 4 cells make a selector switch to isolate turning each cell off as needed so you can remove it and go charge "just that cell" and swap it back in later while running and swap out another(and of course, market the 4 cell system with 5 total cells so you have an extra to be "on charger" always). Everything else I've seen mentioned here I believe has been done already by battery buddy, tekkeon or others.

[Walstib62]

To answer your question, more info. is needed. Specifically, what the voltage and POWER (in watts) requirements are for each device and how much operating time you desire from the power supply. The metering ckt. could be designed to operate full time with LED's at minimal power loss.

Another way to go would be to design a box with multiple outputs, and a continuous output adjustment at each output that one could measure either with a built in metering ckt. or an external meter.

In order to have the "just plug in to recharge" feature, it would also need a charger ckt.

This could all be home-built, but probably easier to buy off the shelf and assemble as a kit.

I am fortunate, as I get free discarded good batteries from work and have the electronics knowledge to build my own stuff.

Good Luck!