DIY Battery or External Battery or Charger or Converter

I would like to know if anybody knows how to make:

-An external battery that can power a macbook or battery charger or AC or DC output etc...


I need to power my MacBook and my Canon G9 (AC adapter directly connected to it or power the charger)


I am aware that I can buy a second MacBook battery and extra Canon Batteries

But this is temporary, cooking up some DIY car battery or solar charging etc... would be extremely helpful


Handcrank? Windpower? Solar?!



I just need pointers at how to strip/mod a MagSafe connector and how much power needs to run through it to run/charge my macbook and how to strip/mod a Canon G9 AC adapter

 

Any more information?

E.g. expected run time, weight requirement, size requirement, budget?

 

-Outlast the MacBook's battery (6+ hours hopefully)

-No weight requirements really... as long as it's not insanely heavy

-Size... fits in a backpack

-Budget... $250?


This needs to be able to power my MacBook AND Canon G9, technically multi-output etc...



This can almost be seen as a professional photo shoot in the middle of nowhere... most likely sunny, decent amounts of wind etc...




Basically I just need to know how wire a bettery to a converter and whatnot so I can connect it to my MacBook or a charger or power an AC plug or DC?

 

If you want simplicity just get a deep cycle marine battery and a 300 watt inverter with clamps to hook to the battery leads. I don't know about runtime, but it should be sufficient.

 

That is the most common answer and quickest dirtiest way to do it...

But there has got to be some way to make a smaller portable solution...



http://www.quickertek.com/products/macbook_charger.php

$500 !!! !??!!? 8-12 Extra hours
They need your MagSafe by the way, so they can butcher it to work...
HOW CAN I BUTCHER MY OWN TO WORK WITH BATTERIES?!



http://www.batterygeek.net/SearchResults.asp?Cat=78

$300 - $750 ! ! ! 7 - 20+ Hours? Depends on model
FUGLY design, looks cheap
Again... seems like these companies are betting on the WATT HOURS... Explain?



http://mikegyver.com/Store/index.html

$400-$850 ! ! ! 10-24 Hours? Depends on model
Way overpriced... Again... WATT HOURS




http://www.hyperdrive.com/HyperMac-External-MacBook-Power-s/91.htm

$200-$500 ! ! ! 10-30 Hours? Depends on model
The newest, the best, they supply a pre-butchered MagSafe cable!




What's up with these wH (watt Hours)?

What is in these batteries?


How can I make my own?!

 

There's always this thing.

 

All I need is the most basic thing ever... BATTERY > CONVERTER/WHATEVER > CABLE > LAPTOP/CHARGER

No air compressor, radio, anti missile defense system, gps, wifi, on-star, itunes, teleporter, microwave, nuclear reactor, boombox or anything like that...

 

as long as you can achieve a total protable voltage at least 5v greater than you highest volt-requirement device you can do it relatively simply.

SLA batteries (sealed lead acid batteries) are smaller version of car batteries, and can charge pretty quicky and have large capacities. for portability reasons, if say you needed to generate 24v (to then be adapted for all your kit) you could use 2x12v 6aH batteries. would be small, but quite heavy. then you need the right connector for each piece of equipment, and would simply need to build a power distribution board with a relatively simple circuit on it to regulate and maintain the specific voltages you require.

to summarise, you would need:

SLA Batteries to achieve a minimum +5v of your highest volt requirement device
Circuit board
Wire+Connectors.


i can help you design it if you want, i used to do this sort of thing for a living

gavin

 

How much would this run me?

As you can see hypermac's 222wH beast can handle 20+ hours on a macbook... that is insane, but $500 is ridiculous


Hopefully someone will start making DIY external batteries and kits online, add some powerful light batteries in a backpack, charge as you go etc...

Not having to buy these insanely priced ones, not to mention the solar backpacks are close to the 4 digits

 

I also want an external battery, Long flights across the world and the cost of business class is crap..

I dunno how a unit like this would work, But in my head I'd instantly use Lithium Ion batteries, and just get a whole bunch of them, and try to fit them in a shape that is comfortable in my backpack. Like in the case of an old power book lol..

In my airsoft days, we'd just shrink wrap and solder a bunch of battery cells together, and use that..

I like the Hyper Mac thing, but it's too pricey..
I'm going to probably buy one of those, depending if I go for the MB or the MBP lol

 

i will attempt some calculations for you based on some easily achievable SLA battery capacities using my laptop as an example.


My laptop requires a maximum current of 3.5A from the main adaptor to function with / without battery, at a voltage of 18.5v

going full out, that meas my laptop can / will consume a maximum of 3.5 x 18.5 = 64.75watts

So, if i would just be powering my laptop from such a device as i propose, assuming the following, 12v 6Ah batteries *2 in series to achieve 24v

Capacity of batteries in series = 6aH

Assumed efficiency of regulator circuit 75% (probably would be much much higher than that)

so 6*.75 = 4.5aH practical capacity / 3.5A power draw = 1.28 hours of use

now this is assuming that the laptop is running 100% and charging the battery to achieve this maximum draw. If you were to remove the battery and use light applications i would suppose that current consumption would probably halve, so your runtime would effectively double to around 3 hours.

And the size of such a battery arrangement would not be too big or heavy

 

12 8aH SLA Battery $20
This sounds pretty good right now!

8*.75 = 6aH practical capacity / 3.5A power draw = 1.72 hours of use
Call it 3:30 to 4 hours now

This math is really really helping me understang this kind of stuff!


Great website to understand Amp hours, watt hours etc... http://www.fridge-and-solar.net/amps.htm


"This could be fuzzy math, but here's one attempt at giving you an average power usage number.

Doing normal things (surfing the web with iChat and iTunes), I get about 3 hours of battery life. Apple claims the battery is a 55 watt-hour battery. According to Wikipedia ( http://en.wikipedia.org/wiki/Watt-hour), one watt-hour is equivalent to 3,600 joules. A watt is defined, according to Wikipedia ( http://en.wikipedia.org/wiki/Watt), as 1 joule/second.

Thus, 55 watt-hours is 198000 joules, 3 hours is 10800 seconds, and the power consumption averages 198000/10800 watts = 18.33 watts.

I could be completely wrong on this, but I think it's about as good an answer as you'll get, unless someone has a Kill-a-watt power meter.

I have a 2.0ghz Macbook by the way"



An 8aH 12V SLA battery equals 56 Watts and a macbook uses about 17 when idling...
So are we talking about this 8aH 12V SLA battery powering for 12+ Hours when doing light work!?

What about connecting the circuit directly to the MacBook? Instead of powering the power brick...?!



Are there any "FLAT" or "FLATTER" batteries?

I should add that this will be in France... I live in Michigan... I will be flying to Germany France Holland Shanghai and Beijing...

 

the power regulator circuit would be directly poweirng the equipment, not powing their own power adaptors. in fact they are remarkably easy and simple to build

For example, to achieve my 18.5 volt @ 3.5a requirement would require:

2x2a 19v TO220 format regulators (to allow for a maximum of 4a when used in parallel)
1x 6a silicon rectifying diode
2*32v 100uF electrolytic capicitors to regulate out any small spikes / dips
1x LED to indicate it is working
1x little fan
1xlittle plastic box
some PCB

at a total cost of around £5, or about £15 if you include the batteries as well

 

Ryobi Li-ion cordless drill batteries in custom case + Custom voltage regulator + modded cable = 30 hours on my TB 18.

 

You can build your own Li-ion battery pack for $250. It'll guarentee to power your macbook for at least 3-4 days straight with a single quick charge. $200 can get you about 80 protected 18650 cells (same ones used in laptops). It'll yield you about 0.75 watt hour of energy. You can spend $50 for a nice li-ion controller and charger and maybe a dc->ac converter to standard household AC.

100 li-ion batteries weighs about 20 pounds which offers very good energy density and easily fits in a small backpack to carry with you. Li-ion also outputs huge amount of energy as well. You can probably power 2-4Kilowatt hours devices with the battery pack safely if you want since Li-ion are designed to discharge at 2-4C safely. The flip side is what happens if you short circuit them. If you have protected cells, then that problem should be almost eliminated. Drawing 100W of power from li-ion battery packs should be a piece of cake.

If you're buying 100 li-ion batteries, you can contact the wholesellers about it.
http://www.dealextreme.com/details.dx/sku.5790

They could probably reduce the price to about $2.50 per cell.

if you're using a good li-ion battery controller, unprotected cells can be used as well. Those will probably cost less.

 

WOW ! ! !

This is amazing information guys ! ! !


I have to make sure I can travel with this battery system to GERMANY FRANCE HOLLAND SHANGHAI AND BEIJING

I am not sure if I can leave it in France or Germany (I will be travelling between both since my project is right over the border in France and my dad lives in Germany) and I might just leave them there since I will be back after China...



If I can achieve 12 hours that would be plenty enough for now! I will only be working from 9 or 10 am to 8 or 9 pm depending on the weather and stuff...

So creating the smallest sized battery pack would be awesome!

I do want it to be less than 10 or 15 pounds though now that I think about it... and keeping it under $150 total would be nice too





"2x2a 19v TO220 format regulators (to allow for a maximum of 4a when used in parallel)
1x 6a silicon rectifying diode
2*32v 100uF electrolytic capicitors to regulate out any small spikes / dips
1x LED to indicate it is working
1x little fan
1xlittle plastic box
some PCB

at a total cost of around £5, or about £15 if you include the batteries as well"

£15 = $23 !?!? That cheap!?




Are there any pre-assembled circuits or DIY kits? I could easily make my own with directions and help... but if I only have to pay a bit more to get something complete that would be sweet!

 

I don't think you need a fan so you can deduct the cost. LOL

Yes.. it's very cheap. If you're carrying the batteries on airlines, be prepared to take it apart.

I suggest buying a battery holder for those batteries so you can take the batteries out and show the design to those "xray machine guys".

 

yes, those components really are that cheap!

trust me, you would want a ;little fan those TO220's can get mighty hot when under load!

if properly assembled you could make the regulator circuit about the size of a packet of "king size" matches so no worries there. Im pretty certain SLA batteries would be OK through airport security, but you would have to check first! (they are almost chemically identical to a standard car battery so soting too weird)

 

Wouldn't a fan be wierd if you're carrying the battery pack around? If TO220 gets hot enough, a medium sized heatsink would do the trick.

 

well, you could either have no fan and large heatsinks that will continue to get hotter inside a sealed case (not a clever idea) or have medium heatsinks and vent it with a teenie chipset-sized fan blowing slowly and quietly?

i know which i would prefer.

probably would not be nice having a backpack catch fire! especially with SLA's / L-ion's in it!!!!

 

It doesnt have to be completely sealed...

But I am asking as to why some companies such as the ones I listed offer 222wH's or even 444wH's with not fan and quite light and portable and stylish... just INSANELY expensive

 

Possibly because there is not a large market for them and it is still a niche product. That Is why I keep building my own ... but they sure arent stylish I build them into old pelican cases

 

Well... I will be at a run down farm filming and photographing my friend and I as we paint murals, we do this yearly.


I just want to make sure that I can film and photograph all day, that means charge my MacBook at least once, or power it at least 2-4 hours until it starts running on it's own power and be able to charge a camera battery a couple times (I will using 3 Canon NB-2LH Batteries)

 

Why not just power the camera and your macbook solely with the battery pack. A 500Whr battery pack can power your laptop + your camera for couple days straight on a single battery charge.

 

I haven't read all the way through the posts, but there is one problem with all of this:

The moment you plug something (like a battery) you will immediately engage the O/S's A/C power plan, which will draw full power from all accessories, peripherals, and components.

Any battery you carry around would have to be a large battery to make it worth while.

 

However, you can change the power mangement settings so the moment you plug something (like a battery) you will not immediately engage in O/S's A/C power plan, which will draw power from all accessories, peripherals, and components.

500Whr Li-ion battery pack can be as small as 2L pop bottle that weighs less than 10 pounds.

 

i think it would be worth doing some research into the best bettery for your needs, i dont have much experience with L-Ion's but once you can find a suitable battery than the votage regulator circuit will still be as i described - dont buy anything too expensive when you can build your own for much muchless!

 

I am just asking around as to what people know about this kind of stuff and I know the exact requirements now:

-Travel Safe
-10lb limit now since I think a 120wH-240wH battery would do just fine
-Fit in a pelican laptop case or something similar that doesnt look crazy outside
-Cost less Than $200 ($250 if it's extraordinary)
-Provide as much power as I can get from $200
-Powers a MacBook and can charge Canon NB-2LH Batteries (AC outlet? DC outlet? What's the difference?) (Or make the circuit adjustable so I can just hook up stripped MagSafe MacBook cables or the Battery Charger/AC Adapter so I can power my camera constantly from the battery pack)

 

DC output would be more efficient but you'll need to buy a DC power adapter for your macbook and camera. When you need house hold AC, you can get a dc->ac adapter for $10 for temperoary use.

AC would be inefficient because you have to convert from dc to ac then ac to dc again.

 

if the camera can be charged by USB that can easi;ly be provided by the circuit

 

HAH! Yes, that would be ideal, but we're talking about a Canon G9...

I can get an AC adapter for it... how easy is it to convert it to DC?

What kind of adapters do I need to make my MacBook DC powered?

 

All of your electronics are DC powered already. For Macbook, you can get a "car power adapter" that takes 10-24V DC. I assume there are car adapter for your camera as well. If the camera doesn't have a DC adapter, you can always buy a $10 10-24V DC-> houseold AC adapter.

 

if you can already get a AC adaptor for it, it will be able to be powerd by the circuit directly, as long as you can get a suitable connector for where it goes into the camera and its voltage requirements aren't crazy

 

Canon doesn't make DC adapters...

I don't think making one should be hard... or is it?


Even so... I think that I will be able to go without charging my camera's battery since I found a 1700 mAh NB-2LH for $23.95 on megabatteries.com which is amazing because my current one is only 750 mAh, so I think having both would work out fine...


Now what do I need to make that battery pack for my macbook?!

 

Build a battery pack to around 15V, get/build a protection circuit so it doesn't discharge below the standard. Then get one of those car adapter that looks like the ones from the link below
http://www.powerstream.com/ADC.htm and hoook it up to the battery pack.

 

So should I strip the MagSafe's wires and connect them to the stiped tip of the DC adapter?

Where can I buy such a circuit?

 

If you can get a hold of a used laptop battery, open the case and you'll find a protection circuit.

 

www.digitalcamerabattery.com

well constructed, heavy duty stuff. I've use their gear powering laptops and digital cameras on mountaintops in subzero blizzards.

 

Ahaha, thank you
They look pretty nice!

Where was this and are you a photographer *obvious*?

I would gladly buy one if I had the money...


But you cannot tell me they didn't make those for under $200

 

There is an 'entry price' for tech like this. Better to save up for the correct tool than to force something cheap to do a job it's not intended for.

 

first of all, do not get a car adaptor for your equipment, they are designed for nothing more than a 12v input which makes them extremely inefficient when they have to "pull up" the voltage to soemthing higher. they are also notoriously unreliable

what is the DC output from your macbooks AC power adaptor? it will say somewhere on the transformer block itself. Then find ourself a suitable connector that fits into the macbook DC socket (where you plug in the AC wall adaptor)

let me know what the specs are and i will design you a power regulator.

 

Oh so are you suggesting just to put enough DC power in there so it goes directly to the MacBook and the AC adapter won't have to do anything?

Output: +16.5V --- 3.65A PSCV600119

I will have to make sure to disable the automatic AC Power Plan on my MacBook since that's what it does...

 

Most car adapter accept 12-16v input. Car adapter only has to pull up to 16v in order to feed power to macbook.
e.g. http://mikegyver.com/IdeasnProducts/Kensington-Magsafe/index.html

What the OP doesn't want to get is car power inverter which is very inefficient and should be only used as a temporary circuit to provide household electricity.

 

yes, you are correct. going DC --> DC is much more efficient than using all sorts of kit to power the AC adaptors. that would be extrremely wasteful.

I will demonstrate why a car adaptor is not a good solution for you:

To use a car adaptor to generate you 16.5v 3.5a (assuming you can find one that capable) would limit the effective run time of the battery. to achieve a 16v pullup from 12v would draw a needless amount of current and would deplete the battery very very quickly to a point where the transformation could not be sustained, even if the battery is only 2/3rds full at that point.

a simple analogy is trying to maintain the pressure of a hosepipe end with less and less water going into it at the other end. at some point the pressure you want will not be achieveable, even though water might still be available.

going from a 24v pull-down as i suggest allows for far greater tolerance of battery charge level to maintain output as most SLA's can not sustain current output below a 9v level discharge, but 2x9v=18, so at that point the circuit would still be functional. you will get much better charge / life ratio that way.

again to the hosepipe, its easy to maintain the pressure you want if there is still lots and lost of water still going in!

so yes, for your 16.5 3.5a volts you would need four of these http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=5164856 in parallel and then two 6a silicon diodes in series on the output stage to drop it by a further 1.2v, thus giving you 16.8 volts, which is well within tolerance for your macbook

 

I'll bet a homebrew battery pack with tens of cells will raise lots of red flags with security check ins.

Why not get adapters for whatever voltage the airline provides? some are 12 volt, some are other voltages.

I have some accessory chargers for IBM battery packs that run off 16 volts. Should be able to manage that from three 6 volt lead batteries, solar cells, or laptop power adapters when near AC. Also it's probably easier to learn to rebuiild LiIon or NiMH packs than designing and building from scratch.

 

People who are building homebrew batteries for backpacks aren't typically the type (with money) who fly airlines that have power points at the seats.

Homebrew battery people fly JetBlue and SouthWest.

 

The reason I wanted the external battery was because I AM NOT CLOSE TO AN AC PLUG ! ! ! lol

I could afford an external battery pack, but I can't charge multiple things from it... and with all the money I saved I could make one that could outlast any commercial external batery and the HyperMac battery is just freaking ridiculous... It's half the price of a MacBook!


I was and am going to be shooting video and pictures for more than 4 hours and making a battery pack is cheaper than an extra battery...

Not to mention I need to power my Camera, MacBook and other devices too...

 

I'm no expert, but check this new product out.

It's a fuel cell and very promising!

http://www.medistechnologies.com/Default.aspx?SecId=133

I know it's only 5.5V but maybe 3 in parallel?