Duracell 5 Hour Portable USB Charger/Battery pack

[mat80c]

On the subject of power supplies and making the raspberry pi portable. I found this nifty little fellow online.

http://www.duracelldirect.co.uk/pno/pps5h.html

Its a rechargeable Duracell battery with two 5v USB power outputs 1800mah capacity and you can pull a maximum of one amp out. When plugged in the wall it works just like a normal PSU now all I need is a touch screen that runs on 5 volts.
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Its a rechargeable Duracell battery with two 5v USB power outputs 1800mah capacity and you can pull a maximum of one amp out. When plugged in the wall it works just like a normal PSU now all I need is a touch screen that runs on 5 volts.

I know its £40.00 but its pretty cool and it will work out of the box.

Has anyone else seen some intresting power supplies?

[geeus]

With a bit of side ways thinking you could build your very own for about 5-6 pounds re-engineering poundland solar garden lights and a usb phone adapter. which I find far more fun that buy something off the peg.

[mat80c]

I’m looking forward to seeing how you get on with that. Factors that concern me include overcharging, capacity and a stable 5 volt feed. Also how many hours are you willing to put into building your own power supply?
Then again £40 is twice as much as a model A, and we mustnt forget the fun factor.

[geeus]

Joking aside I have butchered several of these light units they all contain a NiMH battery and solar cells with a voltage pump. given the solar cell is next to as useful as a chocolate teapot but the availability of the rechargeable battery\'s are without question. with something like a 7805 of more efficient similar IC It is more than possible for very little cash. but if all goes fizzle puff on a large cloud of magic smoke and least you have tried. plus things that go bang are some times more fun than things that don\'t. risky lateral ideas are what the raspberry pi project is all about. (I think). At least we have a very real opportunity of finding out.
regard Gee

[hippy]

The last poundland solar lights I stripped down used something pitiful like a 1.2V 50mAh battery and a COB that pulsed the LED and also used the LED as a light level detector. Very impressive as designed-to-cost products for a specific task but not really useful for much else. I was certainly impressed that half the \'solar cell\' was actually cardboard but convincingly printed to look like the real thing.

I think DIY power supply design, particularly repurposing hardware, is going to be mainly in the domain of those who can, are prepared to take the risk and enjoy the smell of smouldering components, while \'mere mortals\' will be buying off-the-shelf product to do the job.

[abishur]

[quote]Quote from mat80c on October 21, 2011, 22:23
I’m looking forward to seeing how you get on with that. Factors that concern me include overcharging, capacity and a stable 5 volt feed. Also how many hours are you willing to put into building your own power supply?
Then again £40 is twice as much as a model A, and we mustnt forget the fun factor.
[/quote]

The Maxim DS2715 chip would be an easy solution to this issue. It provides charging of up to 12 (I think) NiMH or NiCD batteries (no Li-Ion) and costs about 5 bucks. I was planning to use it on an e-reader, but then the cost of the Kindle dropped making it much cheaper just to buy a kindle outright!

[cougarten]

you can get something similar for 10 bucks or something: an external USB AA-battery pack thing https://www.amazon.de/Batteriefach-HTC- ... 497&sr=8-4

[tufty]

In the UK, there\'s Teck-Net, who have a bunch of options - here\'s an 11,000mAh LiIon-based \"USB charger\" for around 40 quid (yep, that\'s 11 amp/hours, which by my reckoning is 55 hours at 5V, 1W). They also make more \"reasonable\" 5000mAh and 7000mAh devices which can be had for around 20 notes.

I strongly doubt they are the only ones; these are the first I hit on Amazon.

As a sanity note, 5000mAh has basically the same capacity of that for the iPad; that\'s capable of 10+ hours driving screen, wireless and chip..

Simon

[mat80c]

On a power supply note, how about one of these to get your pi working in the car

http://www.ebay.co.uk/itm/Micro-Mini-Ca ... 27bc8a001a

Micro / Mini Car Charger USB Adapter 1000ma High Power
Sorry abou tthe horrible url, there £2.59 each.

[crundy]

I bought myself one of these, primarily to charge my eCigarette batteries while on the go, but I suspect it may be useful for running an R-Pi off:

http://www.ebay.co.uk/itm/180557380272? ... 1497.l2649

2600mAh battery, output 400-800mAh, variable output voltage. OK it wouldn\'t last long, but might give you a couple of hours.

[kattle87]

One thing I don\'t understand...
http://www.ebay.co.uk/itm/2-x-18650-ULT ... 4ab021d542
on the battery, there\'s a \"short circuit, overcharge and discarge protection\". Does that mean I can hook it up to my USB 5V and charge them without any explosions? And then using them with my raspi without killing them?

[abishur]

I\'m going to go with no. Rechargeable batteries, and especially Li-ion batteries, need to be charged properly. Slapping a 5V charge on them and letting them go is never a good idea, you need to use an appropriate charging circuit (though you can design you own for relatively cheap). The short circuit, etc protection is designed not to take any voltage input and scale it down to what it needs, but rather to protect it from an appropriate charging device that is malfunctioning or just poorly designed.

[kattle87]

Perhaps at least there\'s no need for a discarge-prevention circuit. But in the end, buying a USB pack will probably be just cheaper and safer, there are some decent ones for 40€. If you had to go through buying the batteries, the chips for charging, the regulator for 5V output, you are probably spending 30€ anyway, and you risk everything going from explosions to flames everywhere

[abishur]

[quote]Quote from kattle87 on October 31, 2011, 18:04
and you risk everything going from explosions to flames everywhere [/quote]

Which can be fun in it\'s own right

[fdufnews]

You can look at this to charge li-po:
http://www.seeedstudio.com/depot/lipo-r ... ?cPath=155
and more information here:
http://www.seeedstudio.com/wiki/index.p ... _Rider_Pro

If your not confident with your charger you can use this :
http://www.dealextreme.com/p/fireproof- ... -bag-45845

This type of battery with USB outputs can be interesting:
http://www.dealextreme.com/p/6600mah-em ... ters-90291
I bought one but never tested it to its limite. Just used it to power my arduino and some sensors.

[Shadowww]

Wow, branded stuff is overpriced.

http://www.dealextreme.com/p/rechargeab ... tery-73775 - £25, has 5V/9V/12V outputs, and real capacity of it is, of course, not 15000 mAh (chinese vendors overrate stuff a bit), but still not far away - somewhere from 11000 to 13000 mAh.

Also, even better way to power a Raspberry Pi would be a MintyBoost. It\'s a small device which fits in Altoids gum tin, takes 2x AA* and has 5V USB as output (current rating - 0.7A, which is enough to run Minty + mouse + keyboard) - due to it\'s small size and DIYness.

* if you are comfortable with it being bigger than Altoids gum tin, then it can also use LiFePO4 / LiPo / Li-Ion cells as input - be it 18650, 14500, or just flat R/C packs! Only requirement is for input voltage to be under 4.8 volts. That\'s what I have myself - mine Minty has a 18650 holder, and I always have a couple of fully charged ones with me.

[gbl08ma]

I have one of these: http://trust.com/products/product.aspx?artnr=14781
I got it for free from someone who didn\'t want it. I own an old iPod but I don\'t use that battery to charge it (24 hour playback is more than enough). Since the battery is usually just sitting around I thought it could feed a Pi...
Battery specs:
2800 mAh capacity
500 mAh output (this is the main problem)
Charges from USB port, delivers current as USB port (normal size, female port).
Can charge the connected device while charging itself (like a laptop battery would do).

It only outputs 500 mAh, so I thought that if I could get another of these batteries, or if I could get something else that provided more 500 mAh (or even more), I could use two batteries and a Y cable (two USB power cables, that get together on a single one) like seen on many USB-SATA hard drive adapters.

Of course, to make the Pi a real portable thing, I would need a [touch]screen. But even if it\'s not to be made portable, batteries can still act as UPS to you can make sure your Pi doesn\'t loose any digit

[kattle87]

I don\'t want to be rude or anything, but I wouldn\'t trust things from dealextreme. And that 15Ah sounds really fishy. The box is small, how the hell do they packed so much energy?
According to wikipedia, lithium packs at most 250Wh/Kg. that thing weights 270g, let\'s suppose 250 are of battery (I guess it\'s more like 220-230g but nvm), and that thing holds 78Wh (12V*6.5A); 78*4 = 312! Wow, they do better than what general consensus states! And it\'s not by a famous brand! Pick one:
-the branded corporations are screwing us by making us believe there\'s need for better batteries, while the lithium ones can actually put out much more
-that unbranded product is a half-scam.
Actually, making calculations using size, such a high Wh might be possible, But I really don\'t know...
There are some good deals on amazon.uk, and since I\'m from europe, I think they will ship pretty fast to my place. I\'m willing to pay 30£ for a good usb power source, even if they say it\'s \"just\" 7000, it\'s still something I trust a little more than a 15000.

[Davespice]

FYI all, Duracell now have a 3 hour portable charger which is about £20. They have adverts all over the tube network for them.

I am not sure what the current (amps) output is though... I\'ve been looking around trying to find it.

[bradburts]

[quote]Quote from kattle87 on October 31, 2011, 12:04
One thing I don\'t understand...
http://www.ebay.co.uk/itm/2-x-18650-ULT ... 4ab021d542
on the battery, there\'s a \"short circuit, overcharge and discarge protection\". Does that mean I can hook it up to my USB 5V and charge them without any explosions? And then using them with my raspi without killing them?[/quote]

I did not see the protection you said was printed.
Abishur is right to be cautious.
I have worked on battery chargers and I can tell you there is a lot of energy bursting to get out.

I would hope that a single Li-Ion cell has discharge protection otherwise that could be dangerous on charge. There should be two fuses a resetable discharged fuse and a non recoverable deep discharged fuse.

You don\'t need to fully charge your cells, its better not too anyway. If you drop voltage to, say, 3.95V (assuming 4.2V peak) then I would have thought you could float at that voltage.
Get a second opinion on this but that way its a simple linear reg with not much lost capacity.

Overcharge with 5V is a no no. You get \'thermal run away\' which is polite battery manufacturer speak for \'catches fire and might kill people\'.

[Prometheus]

[quote]Quote from kattle87 on November 1, 2011, 13:11
I don\'t want to be rude or anything, but I wouldn\'t trust things from dealextreme. And that 15Ah sounds really fishy. The box is small, how the hell do they packed so much energy?[/quote]
I\'ve seen some tear-downs of packs like that from DealExtreme. The one I saw contained a small battery, and......................

............... some old metal to make it seem heavier, to give the illusion that it was as substantial as the specs claimed. I\'m pretty sure that the brand-names don\'t do that!

[crashingdutchman]

Here is a 12A Rechargeable Portable Emergency USB Power Battery Pack with Power Adapters which should get you going for a while: www.dealextreme.com/p/12000mah-recharge ... r=18534066

Dimensions: 6.30 in x 1.77 in x 0.91 in (16.0 cm x 4.5 cm x 2.3 cm)
Weight: 8.92 oz (253 g)

It\'s US$ 60.80 (~GBP 40)

[sylvan]

[quote]Quote from kattle87 on November 1, 2011, 13:11
I don\'t want to be rude or anything, but I wouldn\'t trust things from dealextreme. And that 15Ah sounds really fishy. The box is small, how the hell do they packed so much energy?[/quote]

15Ah is not a measure of energy.

15Ah at 5v is a measure of energy (75 watt hours). In theory that is enough energy to run a 75 watt light bulb for one hour. But I\'ve never seen a 75w light bulb that would run off 5v, have you?

15Ah at 1.5v is a measure of energy (22.5 watt hours). Notice how the voltage at 1.5v means much less energy than if the voltage were 5v.

And it actually gets even more complicated. A battery does not have some fixed amount of energy in it. For example, if you drain an alkaline AA battery at a rate of 100mA it will have a lot more energy than if you drain it at 1000mA. A NiMH AA will do much better at 1000Ma, and in fact 100mA may be low enough that internal leakage will waste a significant amount of power so the effective energy will be less than if you took it out faster. (This issue is why AA alkalines don\'t do well powering a digital camera with flash.) Some tests: http://www.powerstream.com/AA-tests.htm

The dealextreme spec implies 15Ah at 5v, but like you, I doubt it.

I think it more likely that a pair of primary lithium AA\'s will provide 15Ah if lightly loaded, and most likely actually produce only about 10 watt hours of energy.

[Shadowww]

sylvan, DX specs usually list amp-hours at 3.7V (voltage of internal cells). 5V amp-hours are usually just a bit more than half of that due to low DC-DC conversion efficiency and stuff like that.

[kattle87]

[quote]Quote from sylvan on December 22, 2011, 20:08
15Ah is not a measure of energy.[/quote]

I am an engineer and I\'m terribly ashamed of what I wrote there. I was probably having a stroke at the time of writing
Well, I wasn\'t relating directly mAh to energy, don\'t worry. In fact, when I saw the thing I went on and calculated the J/Kg and J/m^3 of the thing using those values provided by dealextreme: Output: 12V/6500mAh, 9V/8500mAh, 5V/15000mAh
so I was multiplying with the related voltage already. According to wikipedia, the little thing there has more energy per kg of any lithium battery ever built, but it can fit the current lithium technology when it comes to joules per liter. (or the other way around, I don\'t remember now).
Still, fishy as hell