Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: darkloaf on October 16, 2008, 09:18:52 AM
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Hey,
Ive been reading alot about batteries today, but feel no clearer on the one for me (yes I read all the tutorials).
I need to power
- An arduino
- A stepper motor
For a really long time (a day would be great).
Option 1: Use my Camera battery
I have a canon battery charger and a spare battery, perfect voltage for what I need. But, it's Li-Ion, which ive heard tend to explode. As well as this, ive read that I can't dis-charge them bellow 20% or something like that.
I would like todo this though, here's some specs on the battery:
http://www.digiprintuk.com/canon-bp-511511a512522535-p-874.html
Option 2: LiFePO4 Li-Ion
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3785
Seem to be less explosive. But I would have to buy a new recharger ect, would be much more expensive overall.
"9V LiFePO4 battery pack must cut-off at 11.4V during charging and 7.5V during discharging" . How would I do this easily?
Option 3: NiCad
Just not sure if these are good for heavy duty applications. It's for a time lapse camera rig, so a 24hour shoot would not be unusual.
So many options!
Nick
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If you want to power it for a day get a wall wart.
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Option 4 PbAcid.
That's what it's usually used when big motors have to be powered in a portable system.
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re:Trumpkin
My Canon eos 40D can run for 24 hours + on it's battery. And it's powering similar stuff, microprocessor, servo ect.
Acid batteries are just to big for my purposes. I think i'll take my chances with my canon li-ion.
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Option 5: NiMH
This is what I use for most projects. Cheap, easy to use, easy to charge, very good capacity-to-weight ratio. I would only go with Li Ion if wieght is really important to you.
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Cool, ill check it out. Size is my only concern, weights fine. Cheers!
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Well, I guess size is also a factor. NiMH AA cells are not bad, though. A modern AA cell gives you 2500 mAH at 1.2V.
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I use Li-Po for high drain applications.
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They make lead acid batteries that can be quite small. I have 2 of them that I pulled from some old UPSs that are 12v at 7Ah. Depending on what your servo is going to be used for, that should power that system up for a very fair amount of time
-EDIT-
and the whole point, which I forgot to actually say, is that the batteries are actually pretty small. maybe 6inx3inx4in. Worth a shot?
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darkloaf, how many mAh did you calculate you needed for at least your 24 hour requirement?
Any problem with just buying multiple batteries, and swapping out occasionally?
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If you want to power it for a day get a wall wart.
Yes! But if in a remote location where an AC plug isn't available... get a "Car Jump Starter (http://www.autosportcatalog.com/index.cfm?fa=p&pid=3104&cid=43)"... a nice sized 12 volt battery used for starting a car (with a dead battery). Most of those have a built in DC adapter plug (cigarette lighter plug) for which you can buy an off-the-shelf 9 volt adapter (to get your 9V source).
- They recharge easy.
- They are simple to use... and have other uses.
- A great value because they are mass produced.
- Will provide years of service after your time lapse project is over.