Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I made an external battery for my Air
- Thread starter Chipg
- Start date
- Sort by reaction score
Right now I'm waiting to receive my battery kit from Hobby King. I've seen that the new MacBook Air 11" has an internal battery of 4680 mAh. So, I'm glad I picked up a light 3600 mAh from HK. That should give me 75% of charge, I think 3.5 hours
the air's is at 10 ish volts for the mAh rating, your battery is 14.8 volts so at the same mAh rating your 14.8 volt battery will have 40% more capacity.
That said do not order a higher voltage battery for the air, keep it at 14.8 volts.
I have 6 friends now who made one per my instructions, they all think highly of it.
We were out the other night talking about how we all have 14.4 cordless drills, this mens if you want you can use one of those battery packs that already has a charger so you really only need to spend $20 for a used mag safe cord...
Let me know how yours turns out!
How warm does the battery get? I was thinking about buying one of these units for it:
http://www.otterbox.com/OtterBox-3510-Clear/OTR3-3510S-01,default,pd.html
A little drilling for cables and it could be a good enclosure if heat isn't a problem.
http://www.otterbox.com/OtterBox-3510-Clear/OTR3-3510S-01,default,pd.html
A little drilling for cables and it could be a good enclosure if heat isn't a problem.
It stays really cool when used on an Air, a Pro it might get slightly warm because they draw more juice.
I looked into enclosures and found some sweet ones by googling 'aluminum electronics enclosure' but decided against them due to the extra bulk.
----------
These were some of the aluminum enclosures I liked, I'm not going to order any, I need to keep mine small, light and portable, I just throw it in my laptop bag side pocket and go...
http://www.circuitspecialists.com/extruded-aluminum-electronics-enclosures
This is a great idea, but I'd recommend putting this in some sort of hard case or fire safe container. Especially if the battery pack you are buying is a 'soft case' (no hard plastic shell containing the LiPo cells).
If you were to puncture the cells, they can catch fire. If you overcharge it, it can catch fire. If you over discharge - can also catch fire (I'd recommend a voltage cutoff unit as well)
I use LiPo batteries for R/C, and have seen a few catch on fire, and do so quite spectacularly.
Many videos on youtube, here's a couple:
http://www.youtube.com/watch?v=EseOhC8n7ro&feature=related
http://www.youtube.com/watch?v=VswaFOrVM6I
If you were to puncture the cells, they can catch fire. If you overcharge it, it can catch fire. If you over discharge - can also catch fire (I'd recommend a voltage cutoff unit as well)
I use LiPo batteries for R/C, and have seen a few catch on fire, and do so quite spectacularly.
Many videos on youtube, here's a couple:
http://www.youtube.com/watch?v=EseOhC8n7ro&feature=related
http://www.youtube.com/watch?v=VswaFOrVM6I
Thanks for the tip and the videos.
It's very important you buy a correct charger with auto shutoff to prevent overcharging and I also do NOT recommend a quick charger, get a slow trickle charger and you will have no problems. It's high charge / discharge rates and overcharging that can make them explode. Again, Apple uses the same LiPo batteries in their laptops.
It's not just high discharge rates, but also simply over-discharging. Basically if you ever see the pack "puff" (expand), it's time to stop using it.
It's true Apple uses similar cells, but they also have circuitry to monitor the voltage levels, temperature, and so on.
I don't mean to sound negative in regards to your project - I think it's very cool and will likely build one myself.
If it bothers anyone there are other types of battery's they can order, it does not bother me one bit.
Be careful out there!
I just wanted to post a cautionary tale - I just fried the logic board on my 2008 Black Macbook testing an external battery.
I'm not sure what happened. I got the same battery/charger that the OP used, and even bought an airline MagSafe cord on eBay. I was reluctant to test the new rig on my new refurb 11.6/4/128, so I plugged it in first to my old, reliable 2008 BlackMac. It worked! The screen lit up to max brightness and even though the display said 'not charging', I'm sure it was sustaining the internal battery. Success!
So I plugged in the new Macbook Air and .... nothing. No change in screen illumination, no change in the battery indicator. I jiggled the MagSafe connector but still got no charge.
At this point I started to wonder if something had changed in the battery setup so I went back to the BlackMac and plugged it in there a second time. The screen once again lit up and then....smoke started to come out the rear vent. I quickly ripped the MagSafe connector off but the damage was done. The machine will no long accept a charge from *anything*.
I was upset - this was my first Mac and had sentimental value to me. I immediately made an appointment at my local Apple store and got in the car. The Genius was sympathetic and went into the back room to disassemble the machine. He came back with bad news - the motherboard was damaged and a replacement would cost $416. For an almost 5-year-old computer this is not economic so it is effectively dead. I feel like I killed a good friend.
The only good side of this is that I didn't kill my new Air. But I think this battery building business should be left to people who really know what they're doing. I certainly don't fall into that category.
I just wanted to post a cautionary tale - I just fried the logic board on my 2008 Black Macbook testing an external battery.
I'm not sure what happened. I got the same battery/charger that the OP used, and even bought an airline MagSafe cord on eBay. I was reluctant to test the new rig on my new refurb 11.6/4/128, so I plugged it in first to my old, reliable 2008 BlackMac. It worked! The screen lit up to max brightness and even though the display said 'not charging', I'm sure it was sustaining the internal battery. Success!
So I plugged in the new Macbook Air and .... nothing. No change in screen illumination, no change in the battery indicator. I jiggled the MagSafe connector but still got no charge.
At this point I started to wonder if something had changed in the battery setup so I went back to the BlackMac and plugged it in there a second time. The screen once again lit up and then....smoke started to come out the rear vent. I quickly ripped the MagSafe connector off but the damage was done. The machine will no long accept a charge from *anything*.
I was upset - this was my first Mac and had sentimental value to me. I immediately made an appointment at my local Apple store and got in the car. The Genius was sympathetic and went into the back room to disassemble the machine. He came back with bad news - the motherboard was damaged and a replacement would cost $416. For an almost 5-year-old computer this is not economic so it is effectively dead. I feel like I killed a good friend.
The only good side of this is that I didn't kill my new Air. But I think this battery building business should be left to people who really know what they're doing. I certainly don't fall into that category.
I think the issue here is that lithium ion batteries are volatile and can explode. If it is in checked luggage, it can start a fire. If it is carried on, it would be obvious that something happened and the flight crew could do something about it.
The TSA might well be suspicious of a homemade battery with soldered wires, of course, and not let you carry it on.
That's too bad. Agreed that it would have been worse to kill the new Air (that would be about a $765 repair). You might try to see if someone is selling a 2008 MacBook on eBay for parts (maybe you can replace the logic board for less).
Update. I see this logic board for sale. I'm not sure if it is the right one. In any case, the 2008 unibody logic boards seem to be more prevalent on eBay.
Last edited:
Yes - I found a replacement board on eBay for $215, guaranteed to work. I may go that route, as I suppose I have little to lose (except the $215) at this point.
----------
This is close, but I have a 2.4Ghz machine. I did find one that *should* work for $215. I may give that a try.
Macbook Air aluminium External Battery
Hi guys, just thought I'd add a link for the external batteries I use for my 11" MacBook Air and a 15" Retina MacBook Pro.
The company is called HyperJuice and the like is http://www.hypershop.com, they do different sized batteries depending on your needs.
Take a look!
Hi guys, just thought I'd add a link for the external batteries I use for my 11" MacBook Air and a 15" Retina MacBook Pro.
The company is called HyperJuice and the like is http://www.hypershop.com, they do different sized batteries depending on your needs.
Take a look!
That's horrible, I'm really sorry to hear this... I'd like to find out why this happened so it does not happen to anyone else.
Is the input voltage requirement on a 2008 black macbook less then 14.5volts?
Again, I have only tested on a Macbook Air.
I'm not sure about the voltage requirement for a BlackMac, but I do know that I routinely used the same MagSafe adapter from my 2011 MacBook Pro on it with no issues.
I think I reversed the polarity or something, though that doesn't explain why the machine initially indicated a good power source. I will report back if and when I learn more.
Please be careful, I did extensive testing on a friends 2008 Macbook with my battery (the same one you said you used) and had ZERO problems, the laptop battery was fully charged and the status when the external battery was plugged in showed (Charged) just like when plugged into a wall.
It's interesting to see people make suggestions for the expensive 3rd party battery 'hyper juice' and to try to quash this thread...
Anyone else get one going yet?
I took my BlackMac apart yesterday, just to see if I could do it and to get the part number from the logic board. If it wasn't for a YouTube video I wouldn't have been able to do it - you have to remove a *lot* of screws and it is anything but intuitive!
But in the end I could view the internals and after pulling one of the memory chips found the part number. It matches a guaranteed used board on eBay which is going for $215. I am tempted...
Fixing this machine doesn't make a lot of financial sense, but I will probably do it anyway. I've wasted $200 on sillier things.
Can you can hook two together for 14.8 volts? You might want to do some research about doing that with Li-Po batteries.
I have over 75 charges and discharges on my pack with not one hick-up, I love it, it saves me every day or I should say allows me to be more mobile and work outside at the lake where there is no power.
Cycles
Does using this external battery have any effect on the number of cycles of the original battery ?
I assume if you use this method you cycles will be less - can anyone confirm.
I am currently waiting for the HobbyKing battery and a spare magsafe cable and looking forward to relaxed days not worrying about power whoo too.
Does using this external battery have any effect on the number of cycles of the original battery ?
I assume if you use this method you cycles will be less - can anyone confirm.
I am currently waiting for the HobbyKing battery and a spare magsafe cable and looking forward to relaxed days not worrying about power whoo too.
I'd REALLY like to do this but I've seen too many people fry their boards and batteries by doing stuff just like this - people that I thought knew exactly what they were doing. And batteries don't explode nicely - really high intensity fires. I've heard and seen them blow up (I'm a computer programmer who spent most of his early life doing IT work, still do).
I still do a lot of IT work for medical doctors that I know - I'd LOVE a mobile battery solution for my Macbook Air so I don't have to plug in after a full day's worth of work (running from office to office). I just don't have the ****s to do something like this and the commercial products are way too expensive.
I still do a lot of IT work for medical doctors that I know - I'd LOVE a mobile battery solution for my Macbook Air so I don't have to plug in after a full day's worth of work (running from office to office). I just don't have the ****s to do something like this and the commercial products are way too expensive.
Good afternoon people
My battery arrived yesterday and the bullet connector the day before.
Sadly my charger has not arrived yet, should be tomorow
I spent the last hour soldering the cables together and testing. Soldering the magsafe cable to the bullet connectors was done in like 5 mins. I then plugged it into my MBP and heard a slight pop, and hiss. I unplugged it quickely and it stopped. The MBP wasn't indicating that it was being charged.
I checked the cable and found that the end, close to the magsafe was broken. I guess that was the reason for the charger to stop working. I didn't pay anything for the charger because it was a friends who wanted to through it out.
Took me 20 mins to fix this. I stripped the wires and reattached them, used special tape to wrap the wires in. The finished product does not look particularly nice but it seems to do the job.
Although I have not received my charger yet I started testing. Luckily there was some juice in the battery.
I plugged the magsafe into my MBP and the light lit up green, MBP indicated not charging, then it turned orange and it indicated that it is charging.
All seems perfect so far. I checked iStatMenues to see how many Watt are going through the DC input. It rose steadily from 35W to 64W and stayed more or less around 64W. Peaked to 68W shortly, and occasionally drops to 55-57W.
This leads me to my first question. What Wattage should the battery be putting out? Would a wattage like this over stress the zippy battery? I have found nothing on the internet about what wattage can be output. I have a 5000mAh, 18.5V, 25C.
Second question: When I unplug the magsafe the charging light remains orange until I disconnect the bullet connectors. Is this normal? or has something gone wrong?
I am more or less happy with the results so far. I just need to iron out the last few things.
I am planning on making an aluminium case for it aswell
(PS. the repair job on the magsafe wire is only provisional, I will purchase a different magsafe and use the wire. I don't trust it the way it is, and it looks crap. The burnt spots on the tape are form shrinking it with heat. I will also put some of the electrical tape where the bullet connectors are attached)
So you can reduce cycle count of your internal battery significantly if you charge it full, plug in the external when your are using it on the go, and when the external is empty you use the internal. That way you get twice the battery power with only one cycle being added to the internal battery (if you use the internal).
My battery arrived yesterday and the bullet connector the day before.
Sadly my charger has not arrived yet, should be tomorow
I spent the last hour soldering the cables together and testing. Soldering the magsafe cable to the bullet connectors was done in like 5 mins. I then plugged it into my MBP and heard a slight pop, and hiss. I unplugged it quickely and it stopped. The MBP wasn't indicating that it was being charged.
I checked the cable and found that the end, close to the magsafe was broken. I guess that was the reason for the charger to stop working. I didn't pay anything for the charger because it was a friends who wanted to through it out.
Took me 20 mins to fix this. I stripped the wires and reattached them, used special tape to wrap the wires in. The finished product does not look particularly nice but it seems to do the job.
Although I have not received my charger yet I started testing. Luckily there was some juice in the battery.
I plugged the magsafe into my MBP and the light lit up green, MBP indicated not charging, then it turned orange and it indicated that it is charging.
All seems perfect so far. I checked iStatMenues to see how many Watt are going through the DC input. It rose steadily from 35W to 64W and stayed more or less around 64W. Peaked to 68W shortly, and occasionally drops to 55-57W.
This leads me to my first question. What Wattage should the battery be putting out? Would a wattage like this over stress the zippy battery? I have found nothing on the internet about what wattage can be output. I have a 5000mAh, 18.5V, 25C.
Second question: When I unplug the magsafe the charging light remains orange until I disconnect the bullet connectors. Is this normal? or has something gone wrong?
I am more or less happy with the results so far. I just need to iron out the last few things.
I am planning on making an aluminium case for it aswell
(PS. the repair job on the magsafe wire is only provisional, I will purchase a different magsafe and use the wire. I don't trust it the way it is, and it looks crap. The burnt spots on the tape are form shrinking it with heat. I will also put some of the electrical tape where the bullet connectors are attached)
As you are just charging you battery over a different power source. The Computer doesn't run off the external battery unless the the internal battery is fully charged, since then it will use the power that is coming from the external battery.Does using this external battery have any effect on the number of cycles of the original battery ?
I assume if you use this method you cycles will be less - can anyone confirm.
I am currently waiting for the HobbyKing battery and a spare magsafe cable and looking forward to relaxed days not worrying about power whoo too.
So you can reduce cycle count of your internal battery significantly if you charge it full, plug in the external when your are using it on the go, and when the external is empty you use the internal. That way you get twice the battery power with only one cycle being added to the internal battery (if you use the internal).
Attachments
Last edited:
Good afternoon people
My battery arrived yesterday and the bullet connector the day before.
Sadly my charger has not arrived yet, should be tomorow
I spent the last hour soldering the cables together and testing. Soldering the magsafe cable to the bullet connectors was done in like 5 mins. I then plugged it into my MBP and heard a slight pop, and hiss. I unplugged it quickely and it stopped. The MBP wasn't indicating that it was being charged.
I checked the cable and found that the end, close to the magsafe was broken. I guess that was the reason for the charger to stop working. I didn't pay anything for the charger because it was a friends who wanted to through it out.
Took me 20 mins to fix this. I stripped the wires and reattached them, used special tape to wrap the wires in. The finished product does not look particularly nice but it seems to do the job.
Although I have not received my charger yet I started testing. Luckily there was some juice in the battery.
I plugged the magsafe into my MBP and the light lit up green, MBP indicated not charging, then it turned orange and it indicated that it is charging.
All seems perfect so far. I checked iStatMenues to see how many Watt are going through the DC input. It rose steadily from 35W to 64W and stayed more or less around 64W. Peaked to 68W shortly, and occasionally drops to 55-57W.
This leads me to my first question. What Wattage should the battery be putting out? Would a wattage like this over stress the zippy battery? I have found nothing on the internet about what wattage can be output. I have a 5000mAh, 18.5V, 25C.
Second question: When I unplug the magsafe the charging light remains orange until I disconnect the bullet connectors. Is this normal? or has something gone wrong?
I am more or less happy with the results so far. I just need to iron out the last few things.
I am planning on making an aluminium case for it aswell
(PS. the repair job on the magsafe wire is only provisional, I will purchase a different magsafe and use the wire. I don't trust it the way it is, and it looks crap. The burnt spots on the tape are form shrinking it with heat. I will also put some of the electrical tape where the bullet connectors are attached)
As you are just charging you battery over a different power source. The Computer doesn't run off the external battery unless the the internal battery is fully charged, since then it will use the power that is coming from the external battery.
So you can reduce cycle count of your internal battery significantly if you charge it full, plug in the external when your are using it on the go, and when the external is empty you use the internal. That way you get twice the battery power with only one cycle being added to the internal battery (if you use the internal).
Hi, I cant wait to see the runtime for you , i have a 2008 macbook alum. i would love to have a couple spare packs to give me 3-4 hours extra runtime.
please post your results when you get a chance to fully test it.
Thanks!