Which battery to use and charging circuit

[venerable13]

Deffinitively which 2 do you use? There are a lot of possibilities in that forum but don't clarify me.

How can I say to raps to power off when the battery charge is below a level for safety? Very important.

And with this factors:


battery
battery charger
battery protection
order to power off

All the problems with battery were solved.

[john_wage]

Closed 5v output battery solutions will have built in charging and protection circuits, low voltage dropout, and come with their own charger.

Some really cheap or bad knock offs might not, so you should check that these features are present on the item before you buy it.

[venerable13]

This serves?

http://dx.com/2400mah-external.....240?item=7

I think that in months we have "official" alternatives to buy in raps shop. It is worth search now.

[Gert van Loo]

venerable13 said:

...
I think that in months we have "official" alternatives to buy in raps shop. It is worth search now.


I don't think so. The board was never designed for battery operation so I do no think the raspberry-Pi shop will be selling battery packs for it.

[venerable13]

So what do you suggest the previous battery pack is good? Another alternative? Because in battery general forum anyone say one thing. Should have a post resuming all.

[andri]

venerable13 said:


This serves?

http://dx.com/2400mah-external.....240?item=7

I think that in months we have "official" alternatives to buy in raps shop. It is worth search now.



- Capacity: 2400MAH

- Output voltage: 5.5V

I think 5.5V is to high.

[venerable13]

It is in a range, but if you want more precision:


diode
zener
resistor
linear efficient regulator

[john_wage]

The battery pack you linked to has the wrong connector interface, you should have one with micro-B USB, unless you want to do some soldering.

Also try to find something that is closer to 5V.

Also as a side note for general portable battery applications:

I've noticed that not many people seem to be worried about how to power a monitor. Screens need a PSU too, and what's the point of a mobile RPi if you can't see any output from it?

[venerable13]

ok I oppened eyes. I"ll use a laptop battery 4400mAh or similar and a power charger. Now all is though.

To power normally:

-an ATX PSU

-a laptop charger hacked to 5V.

-a mobile charger

-other alternatives?

To power with battery:

-charging circuit for laptop battery, ideas?

-linear regulator for 5V, this is more easy.

-circuit driver to use laptop screen with raps, it is clear.

Anyone can help me in these projects? Put your interest below

[jbeale]

The easiest thing might be a 12V battery, and a mobile phone charger that plugs into the 12V socket in a car, and produces 5V 1A (these are pretty cheap). I guess you'd need also to get the socket, to connect to the 12V battery also, unless you wanted to hard-wire it. Plenty of off-the-shelf 12V  battery chargers around too.

[john_wage]

I just don't see why you seem to be looking for DIY solutions for products that are readily available on the market already.

And the fact that you're basically asking others to do it FOR you.

[venerable13]

I need help for this I write here. Which solutions are available? I asking others to help me, not to do it for me. You're wrong. There are a lot of solutions for that I want to simplificate in some and recollect it in a post or site to help others.

Thnks jbeale, another idea more to the list.

[venerable13]

With 230V:

A normal power supply here -> 5V – 2A, for good price.

With batteries:

Without screen:

Battery 1 7.4 drops to 5V with a linear regulator 1.5-3A.

Battery 2 the same but with more current.

Charger

With screen:

You have to use a laptop battery to supply the screen because it needs more that 5V to function and do a charging circuitry. Also use the laptop charger.

All is ok?

Do you have to object anything john_wage?

[john_wage]

I misunderstood your post then.

About the latest items, they should be OK but it's hard to know for sure, not much information available on them, the 5V regulated switching PSU seems a little bit iffy, it might have too much switching noise left on the output signal (cheap ones often do), it's easily fixable with own inductor, but.. also it doesn't come with mains cable, and probably no output cable or connector either, once you are adding up the cost of all those extras you might as well buy a better quality phone charger.

[john_wage]

Also those RC batteries are made for a very high discharge rate, I don't know how that will affect their performance, but any serious vendor should be able to offer proper datasheets on batteries, because it's important.

[john_wage]

Did some quick googling for potential batteries that I might use if I was looking for a portable solution.

Major positive about these are the dual 5V and 12V outputs, that would be 2 problems solved in 1 pack.

Edit:

Product was out of stock.

Here is another place to buy it

http://www.saferguard.com/acce.....amera.html

[Boreatton Scouts]

If you need to go portable, a pico projector gives you a Pi sized device with a big screen and comes battery powered!

eg Optoma PK320 works for me!

[venerable13]

All are good ideas but I keep that waiting is the better solution, if in the raps shop there isn't a portable solution (bizarre) on other sites yes, because it will be a super sale product and it significate a good oportunity for the sellers. So we may wait. The safer guard solution is perfect but has high price for my opinion.