External Battery Pack - Could I use this? - SOLVED!!!!! Whoo hoo!!!! - Hotwire! Hardware Mods, Accessories and Insights

Coco

7

External Battery Pack - Could I use this? - SOLVED!!!!! Whoo hoo!!!!

« on: 06 / November / 2010, 14:53:42 »

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Hi,

I have a Philips Power 2 Go SCE7640 rechargeable power pack -

http://www.philips.co.uk/c/power-solutions/rechargeable-power-pack-sce7640_12/prd/
http://www.trustedreviews.com/peripherals/review/2009/05/17/Philips-Power-2-Go-SCE7640-Rechargable-Power-Pack/p1

Would anyone be able to offer some advice on if it's possible to use this as an external battery for my SD800 (IXY 920IS, I bought it in Japan!) which uses the usual NB-5l battery (3.7v 1020mAh).

I've had a good look around this forum and seen the excellent tutorial on how to make your own fake battery and would be looking to make one which i could then connect to the Philips rechargeable power pack if possible without blowing my camera up! I have limited electronics knowledge and would appreciate any advice anyone could give me.

I couldn't get the full spec from the Philips website as it was down however from the back of the pack the spec is as follows

Output : DC19V Max: 2000mA
DC5.6V Max: 350mA

The battery can be used for running a laptop/charging ipod etc and has a USB output and a DC16-19v output socket with various different adaptors.

Thanks in advance.

« Last Edit: 17 / November / 2010, 13:55:37 by Coco »

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Coco

7

Re: External Battery Pack - Could I use this???

« Reply #1 on: 14 / November / 2010, 15:02:26 »

Could i use this connected to the 19v battery output and regulate it down to 3.7v-4.3v?

http://www.maplin.co.uk/Module.aspx?ModuleNo=3488

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Microfunguy

4037

Re: External Battery Pack - Could I use this???

« Reply #2 on: 14 / November / 2010, 19:32:00 »

It seems that board needs an AC supply, 28V maximum (assuming that information is correct).
Maybe you can also use a DC supply.
Try to get more information.

Do you want to use this outdoors ?

Is it for long-duration time-lapse ?

If so, and the above is not suitable, you can buy high-efficiency switching regulators that you could power from a 6V sealed lead-acid battery.

I think they are used by aero-modelers.

You may have to buy from US, we can find out.

David

« Last Edit: 14 / November / 2010, 19:34:44 by Microfunguy »

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Coco

7

Re: External Battery Pack - Could I use this???

« Reply #3 on: 15 / November / 2010, 13:41:55 »

Thanks Microfunguy,

Yes and Yes, outdoor timelapses.

I have built Timescience's "fake battery" and assembled the same 3 x AA battery packs used by jt256 (thanks!) and it works well.

I only wanted to see if it was possible to use the Philips battery pack as i already had it and it's in a nice neat rechargeble pack (plus it would give me another use for it and save me money) oh and last give me project to mess about with and expand my very, very limited knowledge!

I'll have a look for a high-efficiency switching regulator and take it from there.

Thanks

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Microfunguy

4037

Re: External Battery Pack - Could I use this???

« Reply #4 on: 15 / November / 2010, 15:06:21 »

You want one of these and a 6V battery :-

http://www.dimensionengineering.com/DE-SWADJ.htm

Also, search this forum for 'switching regulator'

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Coco

7

Re: External Battery Pack - Could I use this???

« Reply #5 on: 17 / November / 2010, 13:48:27 »

Thanks again Microfunguy!!!! You rock!!!

I bought the DE-SWADJ and the breakout board below.

http://www.active-robots.com/products/components/10w-step-down.shtml
http://www.active-robots.com/products/components/voltage-regulator-breakout-board.shtml

I've just connected it up and tested it, it works an absolute treat!

Using my fake battery i can connect it to the Philips rechargeable battery with the regulator after having adjusted the output down to 3.7v. I've got loads of options now!

I can use multiple 3 x AA packs with my fake battery or the Philips battery with my fake battery or a suitable DC mains adapter through the regulator and into the fake battery!

The breakout board allows me to easily connect the wires from the fake battery and also use different connectors from either the Philips battery or a DC mains adapter without.

Hmm, i just wonder how long the 870IS is going to last when i start taking timelapses on my 16GB cards.

CHDK is the dogs!!!

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Microfunguy

4037

Re: External Battery Pack - Could I use this? - SOLVED!!!!! Whoo hoo!!!!

« Reply #6 on: 17 / November / 2010, 14:54:23 »

That came quickly and the price is good.
May get one myself.

It does not say what the minimum difference between input and output voltage is required to be.

Three AA's would be 3.6 to 4.5V depending on battery type.

Wonder if that is high enough voltage ?

David

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Coco

7

Re: External Battery Pack - Could I use this? - SOLVED!!!!! Whoo hoo!!!!

« Reply #7 on: 17 / November / 2010, 17:21:14 »

I'm getting 3.9-4v out of 3 x AA 1.2v 2000mAH NI-MH which is working fine (as a test i left it running over 7 hours on 2 x (3 x AA) and it took over 700 photos and was still going strong.

Not sure about the min difference between the input/output voltage using the regulator however if it means anything i tested the output of the Philips battery before then connected it to the regulator and checked the output at that side... output direct from the battery was 18.9x volts and was the same (not sure about the "x" difference) on the output of the regulator prior to making any adjustment on the screw.

What i did notice though was that when i adjusted the regulator down to 3.7v and then switched on the camera, according to CHDK the voltage was coming in at 3.3v.

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Microfunguy

4037

Re: External Battery Pack - Could I use this? - SOLVED!!!!! Whoo hoo!!!!

« Reply #8 on: 17 / November / 2010, 18:39:15 »

No, that is not what I mean.

It is a step DOWN regulator, that means the voltage connected to has to be more than the required output of 3.7V.

If this was a conventional linear regulator such as the 3.3V LM1085, the input voltage would need to be at least 5.2V at 3 amp load (and that is a low dropout compared to older regulators).

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mariush

63

Re: External Battery Pack - Could I use this? - SOLVED!!!!! Whoo hoo!!!!

« Reply #9 on: 29 / November / 2010, 12:26:52 »

Wouldn't it have been easier to just get one of these and use the 3.3V DC output ?

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=207

These things take 12V DC and output 3.3V, 5V and 12V so you could use either 3.3V (close to 3.7V, don't think the camera would mind) or 5V (hopefully not too high for the camera)

Some of those PicoPSUs except a wide range of voltages, so I suppose you could use a car battery that outputs 12-14V or maybe combine it with a laptop power brick.

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