I made an external battery for my Air

[Monkeyat]

Can you provide a link please and how much was that?

Of course! Here it is : http://www.note-x.com/16-volts/5838-adaptateur-secteur-chargeur-alim-.html

Price : 25 euros in France. All the web site is in French and I don't know if they ship international. But Chipg, if you're really interested and they don't ship to you, I can eventually ship that to your address... no problem

 

[Creek0512]

A lipo cutoff would be ideal. Similar to this: http://www.teamnovak.com/products/lipo_cutoff_module/index.html (would need one appropriate for a 4S voltage pack if that is what people are using).

I don't know that that is really what you would want if your are powering a notebook.

I would suggest a simple low-voltage alarm/buzzer with an audible warning. They can be found for less than $10 online.

Just google "lipo alarm" their are a lot of options, just make sure it will work with the number of cells in the battery you have.

 

[Chipg]

I don't know that that is really what you would want if your are powering a notebook.

I would suggest a simple low-voltage alarm/buzzer with an audible warning. They can be found for less than $10 online.

Just google "lipo alarm" their are a lot of options, just make sure it will work with the number of cells in the battery you have.

Are there any programmers here that could write a simple app to sound an alarm when the voltage gets to low? I know it can be done because iStat Menu shows the battery/input voltage on an Air so it has the voltage sensors.

 

[The-Pro]

First Test!!

Well I have finished running my first test.
Yesterday I plugged in my battery and used it for about 2.5-3 hours, today I was using it for 2 hours and 3 minutes before it died.
What I was doing during all the time yesterday and today when having the battery plugged in was regular browsing and watching videos online during about 80% of the time. My MBP hat a power consumption of 20W +-5W during the entire time.
So it lasted for a good 4.5 hours, mainly watching videos, quite good I reckon. Considering that when I am on the go, mainly word processing and really basic browsing perhabs, the power consumption is under 10W the entire time!! So I should theoretically get 8 hours out of it

Well I had a little crisis here
After the battery died I plugged it into my charger and the charger recognized it as a 4cell battery. I was a bit confused and scared that I had all ready broken the battery or it had a fault. So I plugged the battery into another LiPo charger from an older race car which does not recognize cell numbers or anything, doesn't balance charge either and let it charge the battery (set to 18.5V) for 2 mins. It added 120mAh of charge. Then I plugged the battery into the new charger again and it is recognized as 5cells. Guess the battery really was over discharged so there wasn't any charge at all left in the cell and therefore could not be identified. Its charging again now and despite me setting balance charge and attaching the balance lead 3 cells are at 3.63V, 1 cell at 3.69V and the last cell at 3.70V. Ill see how it goes. I guess it will charge the three lower cells first then do all. Ok it has charged the three lower cells and now all 5 are at the same voltage, All good
I wont discharge it completely again

 

[Chipg]

Well I have finished running my first test.
Yesterday I plugged in my battery and used it for about 2.5-3 hours, today I was using it for 2 hours and 3 minutes before it died.
What I was doing during all the time yesterday and today when having the battery plugged in was regular browsing and watching videos online during about 80% of the time. My MBP hat a power consumption of 20W +-5W during the entire time.
So it lasted for a good 4.5 hours, mainly watching videos, quite good I reckon. Considering that when I am on the go, mainly word processing and really basic browsing perhabs, the power consumption is under 10W the entire time!! So I should theoretically get 8 hours out of it

Well I had a little crisis here
After the battery died I plugged it into my charger and the charger recognized it as a 4cell battery. I was a bit confused and scared that I had all ready broken the battery or it had a fault. So I plugged the battery into another LiPo charger from an older race car which does not recognize cell numbers or anything, doesn't balance charge either and let it charge the battery (set to 18.5V) for 2 mins. It added 120mAh of charge. Then I plugged the battery into the new charger again and it is recognized as 5cells. Guess the battery really was over discharged so there wasn't any charge at all left in the cell and therefore could not be identified. Its charging again now and despite me setting balance charge and attaching the balance lead 3 cells are at 3.63V, 1 cell at 3.69V and the last cell at 3.70V. Ill see how it goes. I guess it will charge the three lower cells first then do all. Ok it has charged the three lower cells and now all 5 are at the same voltage, All good
I wont discharge it completely again

Just so others know, you are using a Macbook Pro not an Air, right? which model is it? a 15"???

 

[wellokthen]

This is THE BEST thread

First, what an amazing discussion this is. I've been goggling off and on for the past year or so for external batteries. All I could find was commercial stuff (Hypermac/juice, bitnix, etc.), some of which is very impressive--all of which is pricey.

Well, commercial products and just plain crazy-people rigs (like twenty car batteries twist-tied to an old APC controller or some crap; scary). Seemed to me there had to be someone out there with the smarts to hunt down the right parts and explain the assembly. Finally, on like the 10th page of hits (AFTER excluding the commercial sites from the search), I found you. Sad that google seems dedicated to driving business to commercial sites, by hook or crook. Sell-outs. Ah well.

One thing I haven't read anything on in this thread is the discharge rate. My understanding (which is very limited) is that the higher the rate the better--an attempt to draw faster than the max/burst discharge rate of a lipo can cause fire. What I don't know is what the rate needs of the 2010 MBA are. I'm leaning toward the 4s1P 4000mAh 40c (about $35US), thinking that the MBA couldn't need more than that. Indeed, my gut tells me that a MBA should not require bursts like a RC device might, so 15-20c might be more than sufficient. Then again, my gut also told me that no one would take Sarah Palin seriously, so ... now I have trust issues with what my gut reports.

Is getting the 40c a waste of money, since I'll only be using this battery for my MBA, iPad, and (rarely, since I use a mophie case) iPhone? I could get the same size battery for less than $35 if I go with, say, a 20c, or a larger capacity for the same $35. Thoughts?

Also, does this look like it would be a good choice? It's higher output, as with the others mentioned here, but has a slightly higher rated USB port (say, for more efficient iPad charging).

Still trying to figure out the alarm issue. Some of the monitors on Hobbyking say that they have alarms, shutoffs, etc., but it's not clear to me whether this is programmed by the RC device or whether it is a stand-alone thing, requiring no code.

I plan to order the parts this weekend and, hopefully, assemble next weekend. I'll post pics and results.

 

[The-Pro]

Just so others know, you are using a Macbook Pro not an Air, right? which model is it? a 15"???

---> Its a 2010 15" 2.66GHz i7 where I am using the battery with so far, it also works flawlessly with a 2009 17" MBP. I will try it out with my older 17" soon, its at a different location <----

 

[Chipg]

First, what an amazing discussion this is. I've been goggling off and on for the past year or so for external batteries. All I could find was commercial stuff (Hypermac/juice, bitnix, etc.), some of which is very impressive--all of which is pricey.

Well, commercial products and just plain crazy-people rigs (like twenty car batteries twist-tied to an old APC controller or some crap; scary). Seemed to me there had to be someone out there with the smarts to hunt down the right parts and explain the assembly. Finally, on like the 10th page of hits (AFTER excluding the commercial sites from the search), I found you. Sad that google seems dedicated to driving business to commercial sites, by hook or crook. Sell-outs. Ah well.

One thing I haven't read anything on in this thread is the discharge rate. My understanding (which is very limited) is that the higher the rate the better--an attempt to draw faster than the max/burst discharge rate of a lipo can cause fire. What I don't know is what the rate needs of the 2010 MBA are. I'm leaning toward the 4s1P 4000mAh 40c (about $35US), thinking that the MBA couldn't need more than that. Indeed, my gut tells me that a MBA should not require bursts like a RC device might, so 15-20c might be more than sufficient. Then again, my gut also told me that no one would take Sarah Palin seriously, so ... now I have trust issues with what my gut reports.

Is getting the 40c a waste of money, since I'll only be using this battery for my MBA, iPad, and (rarely, since I use a mophie case) iPhone? I could get the same size battery for less than $35 if I go with, say, a 20c, or a larger capacity for the same $35. Thoughts?

Also, does this look like it would be a good choice? It's higher output, as with the others mentioned here, but has a slightly higher rated USB port (say, for more efficient iPad charging).

Still trying to figure out the alarm issue. Some of the monitors on Hobbyking say that they have alarms, shutoffs, etc., but it's not clear to me whether this is programmed by the RC device or whether it is a stand-alone thing, requiring no code.

I plan to order the parts this weekend and, hopefully, assemble next weekend. I'll post pics and results.

Thanks man!

It's my understanding that the battery discharge rate listed as 15C, 20C, 25C, 30C, 35C, 40C = 10 times / 15 times / 20 times / 25 times / 30 times / 35 times / 40 times the capacity of the battery.

So a 10C 4400mAh pack can be discharged at a maximum of (4.4x10) = 44 AMPS max discharge. There is NO WAY an Air will require 44 amps under any circumstance so you can save money and get a low C rating like a 10C or 15C, you have to remember these packs are made to power RC helicopters and discharge the full pack 2 or 3 minutes if need be.

I think a 40C battery is a waste of money, I'd use the savings on a larger mAh size and go with a 10C, 15C or 20C battery.

You should be fine with that USB cigarette lighter power adapter, it is 2 amps so that's perfect for an iPad.

Let me know how yours turns out!

 

[The-Pro]

Thanks man!

It's my understanding that the battery discharge rate listed as 15C, 20C, 25C, 30C, 35C, 40C = 10 times / 15 times / 20 times / 25 times / 30 times / 35 times / 40 times the capacity of the battery.

So a 10C 4400mAh pack can be discharged at a maximum of (4.4x10) = 44 AMPS max discharge. There is NO WAY an Air will require 44 amps under any circumstance so you can save money and get a low C rating like a 10C or 15C, you have to remember these packs are made to power RC helicopters and discharge the full pack 2 or 3 minutes if need be.

I think a 40C battery is a waste of money, I'd use the savings on a larger mAh size and go with a 10C, 15C or 20C battery.

You should be fine with that USB cigarette lighter power adapter, it is 2 amps so that's perfect for an iPad.

Let me know how yours turns out!

That is very interesting. good to know how that works. I went with a 25C, cheapest in the hobbyking europe store, didn't want to take 15C although that would probably have been ok too, would've saved me another $15
I wanted to make sure I don't stress the battery if I decide to do some heavy work on the go on my MBP (would use about 45W up to 60W).

 

[icanmac]

quick question

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!

Macmodmachine, Id like to get in contact with you to discuss some things but id rather not do it on this forum

 

[Chipg]

Anyone else get one made yet?

 

[wellokthen]

Prices

All,

A few things. I noticed that if I do a parts search here, the prices I get (even when it links right back to HobbyKing) are a few dollars cheaper--at least with the US warehouse. Also, if you have nothing in your basket at hobbyking and a page open to a product, they will offer a slight discount (around two dollars on a $25-35 battery, $.50 on connectors, etc.).

As a result, I'll be ordering these parts today--unless one of you sages cautions against:

ZIPPY Flightmax 5000mAh 4S1P 20C
$27

Turnigy Accucel-6 50W 6A Balancer/Charger w/ accessories
$23

HXT 4mm Gold Connector w/ Protector (10pcs/set)
$4

I've got a few leads on dead power adapters with the magsafe attachment. On that, am I right that the form factor and the pinouts are the same with both the original magsafe and the "L" mag? So either would work?

Also, weirdly, the size of the bullet connector for the Zippy battery I initially took a shine to isn't listed. Just says "Bullet (Deans Type)." But the hobbyking site pitched me on the 4mm when I put the zippy into my cart--I'm hoping that it knows what I don't. Suppose it doesn't matter much, since I'll prob go with the 5000mAh/20c, and it does list the connector size (4mm).


POSSIBLE ADDITIONS / SUBSTITUTIONS:

(1) Zippy/5000mAh/4S1P/15C

$30​

Can't figure out why these two batteries are priced this way. The only difference I can see between this one and the one I plan on ordering is that this is 15c and the one I'll likely get is 20c. I'm persuaded by Chipg that 15c is fine--except that the 15c is--objectively--a lower rated battery (even if, for our purposes, it doesn't matter), yet it's four dollars more. Is there a DOWN side to ordering the 20c rather than the 15c?

(2) Hobbyking Wireless Battery Tracker w/ Free Battery 869.5Mhz

$30​

The wireless is overkill, I'm sure. Question is, is it sophisticated enough not to need any code to get alarms, shutdowns, etc.?

(3) IMAXB6 - IMAX B6 Charger/Discharger 1-6 Cells [b6AC]

$40​

This is the charger I keep coming back to. But it seems more than I need, yeah? I might make one of these for my wife's MBP is all goes well. (She's not keen on anything hacked touching her mac, so we'll see. )

 

[Chipg]

All,

A few things. I noticed that if I do a parts search here, the prices I get (even when it links right back to HobbyKing) are a few dollars cheaper--at least with the US warehouse. Also, if you have nothing in your basket at hobbyking and a page open to a product, they will offer a slight discount (around two dollars on a $25-35 battery, $.50 on connectors, etc.).

As a result, I'll be ordering these parts today--unless one of you sages cautions against:

ZIPPY Flightmax 5000mAh 4S1P 20C
$27

Turnigy Accucel-6 50W 6A Balancer/Charger w/ accessories
$23

HXT 4mm Gold Connector w/ Protector (10pcs/set)
$4

I've got a few leads on dead power adapters with the magsafe attachment. On that, am I right that the form factor and the pinouts are the same with both the original magsafe and the "L" mag? So either would work?

Also, weirdly, the size of the bullet connector for the Zippy battery I initially took a shine to isn't listed. Just says "Bullet (Deans Type)." But the hobbyking site pitched me on the 4mm when I put the zippy into my cart--I'm hoping that it knows what I don't. Suppose it doesn't matter much, since I'll prob go with the 5000mAh/20c, and it does list the connector size (4mm).


POSSIBLE ADDITIONS / SUBSTITUTIONS:

(1) Zippy/5000mAh/4S1P/15C

$30​

Can't figure out why these two batteries are priced this way. The only difference I can see between this one and the one I plan on ordering is that this is 15c and the one I'll likely get is 20c. I'm persuaded by Chipg that 15c is fine--except that the 15c is--objectively--a lower rated battery (even if, for our purposes, it doesn't matter), yet it's four dollars more. Is there a DOWN side to ordering the 20c rather than the 15c?

(2) Hobbyking Wireless Battery Tracker w/ Free Battery 869.5Mhz

$30​

The wireless is overkill, I'm sure. Question is, is it sophisticated enough not to need any code to get alarms, shutdowns, etc.?

(3) IMAXB6 - IMAX B6 Charger/Discharger 1-6 Cells [b6AC]

$40​

This is the charger I keep coming back to. But it seems more than I need, yeah? I might make one of these for my wife's MBP is all goes well. (She's not keen on anything hacked touching her mac, so we'll see. )

Looks good! Also consider this or a similar one to it to monitor the cell voltage, it sounds an alarm when the voltage drops to a level that you set:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18588

 

[wellokthen]

Argh

What an annoying site Hobbyking is! American flag freakin splashed all over the place, but it wouldn't let me place the order--scolding me for ordering from different warehouses?! Turns out, "global" is a warehouse unto itself. Now, if you are ordering connectors, then when hobbyking says they ship globally, they mean from any of their warehouses; but that's the only time globally means "wherever you are." If you select items from the "global," even if it says "us warehouse," then it won't let you add it to the basket. Global--US is not the same as US. Crazy. And everything in the cart must be from the same warehouse.

A poorly designed site. They bury the search field at the bottom of the page (don't think I've ever seen that at a PARTS DEALER, where, you know, people need to search for parts). And, they made me establish an account (addy, phone, whole nine yards), just to as a question.

To top things off, the US warehouse is out of every, single charger they carry. Seriously, a north american run on lipo chargers?! Really, look at the pic. Mental.


So, until their customer service gets back to me I can't order the items--and I'm not particularly hopeful, since none of their other "customer service" things are operational (spent an hour trying to generate a chat; no email addy). I could order everything from the German site, but then the $57US of parts is $80, which seems like an unreasonable cost hit just because the hobbyking hasn't the first idea how to design or maintain a website. If I have to fork over an extra $20, I'd rather it be to a company that didn't suck 3 hours out of my life with their crap site.

If anyone can recommend a NOT hobbyking site, that would be great. Otherwise, I'll probably be stuck with Amazon or ebay.

 

[Alameda]

What do you expect? Hobby king is an electronics freak with a ton of stuff in his basement. It's not Amazon.com. This thread probably depleted his inventory.

 

[The-Pro]

I talked to customer service and at one point I told them that its a very poorly designed site and they should do something about it. They took it into consideration haha

 

[wellokthen]

Huh?

What do you expect? Hobby king is an electronics freak with a ton of stuff in his basement. It's not Amazon.com. This thread probably depleted his inventory.

What is your evidence for this claim? He is an unusual "electronics freak," since he has warehouses in Germany, the US, Australia, and China. People on this thread have reported ordering from the US and the German warehouses. And a few domain names point to this site (hobbyking and hobbycity, that I know of). So, actually, like Amazon. More over, the stock quantity is not the problem (except regarding the charger I note); the problem is the site's failure to make clear (a) what they have and (b) what combinations are permissible in a single order.

----------

I talked to customer service and at one point I told them that its a very poorly designed site and they should do something about it. They took it into consideration haha

Really maddening to have to scour the entire site for a few really common items.

So you managed telephone support? A us call? Maybe I'll give it a try. Prob a M-F/9-5 sort of thing, though.

 

[CrAkD]

this thread scares the crap out of me. these apple computers are too expensive to chance something like this in my opinion. I left my macbook on a shelf infront of my ac and the ac spit ice into it during a weekend I was away. thing is fried beyond belief. it was 5 years old and i was bummed out i cant imagine how distraught id be if I fried a brand new mba.

 

[wellokthen]

this thread scares the crap out of me. these apple computers are too expensive to chance something like this in my opinion. I left my macbook on a shelf infront of my ac and the ac spit ice into it during a weekend I was away. thing is fried beyond belief. it was 5 years old and i was bummed out i cant imagine how distraught id be if I fried a brand new mba.

Dude, that rots! (Not to kick a guy when he's down--but leaving a laptop near an AC?!) Still, you must have freaked. I would have.

Personally, I think that following your instinct is exactly the right thing to do. If this sort of project makes you anxious, then it's probably a bad idea for you to tinker. But when people do the calculating for me (explaining as they go), and I can verify the results from at least two other sources, I'm less squirrelly about it. (To be truthful, though, I've fried out one or two smaller things.)

How long ago did this happen? Did a mac tech look at it to tell you exactly what is/isn't fried? If it's just the mobo, you might get another on ebay.

 

[CrAkD]

Dude, that rots! (Not to kick a guy when he's down--but leaving a laptop near an AC?!) Still, you must have freaked. I would have.

Personally, I think that following your instinct is exactly the right thing to do. If this sort of project makes you anxious, then it's probably a bad idea for you to tinker. But when people do the calculating for me (explaining as they go), and I can verify the results from at least two other sources, I'm less squirrelly about it. (To be truthful, though, I've fried out one or two smaller things.)

How long ago did this happen? Did a mac tech look at it to tell you exactly what is/isn't fried? If it's just the mobo, you might get another on ebay.

since it was so old I assumed it was pointless. when i plug it in and push the power key the screen turns white. no apple logo no noise just white. I assume the logic board is def toast but since the thing has ALOT of water in it i wouldnt be surprised if the keyboard, ram and HD are gone too. I had just put a new battery in it before so thats prob toast too because i cant get the white screen unless its plugged in.

 

[The-Pro]

2nd Test

Well I did my second battery life test yesterday. I am amazed! I was doing very slight browsing, occasional video (added up maybe 30-45mins) and a little text work in pages. Altogether I used the battery for 8 hours 30min! Power consumption was between 8-14W. MBP fully charged in during the entire process so the battery way only supplying the power the computer needed.

I unplugged the battery after 8h 30mins, as I did not want to fully drain it. I guessed it would be nearly empty so I stopped using it. When I plugged it into my charger it was again only recognized as a 4 cell battery. So i fed a constant charge into it through a different charger for 3 mins, and it was recognized as a five cell again. Can this be a sign that a cell is damaged? As its probably the same one which is discharged more then the others.

 

[Alameda]

What is your evidence for this claim?

None But this is obviously a small business without the resources that a larger company has.

 

[Chipg]

Well I did my second battery life test yesterday. I am amazed! I was doing very slight browsing, occasional video (added up maybe 30-45mins) and a little text work in pages. Altogether I used the battery for 8 hours 30min! Power consumption was between 8-14W. MBP fully charged in during the entire process so the battery way only supplying the power the computer needed.

I unplugged the battery after 8h 30mins, as I did not want to fully drain it. I guessed it would be nearly empty so I stopped using it. When I plugged it into my charger it was again only recognized as a 4 cell battery. So i fed a constant charge into it through a different charger for 3 mins, and it was recognized as a five cell again. Can this be a sign that a cell is damaged? As its probably the same one which is discharged more then the others.

Aren't these battery packs awesome!

I posted a link for a voltage monitor a few posts above this one, they are cheap and will sound a buzzer at a pre determined voltage you set. On the Air's, iStat Menu tells you the voltage of the battery pack.

 

[Brandon0448]

Well I finally got around to putting together my battery. It was quick and easy and works great so far! I have not tested out how long it lasts yet but I will eventually. Here are the picture of it. A little shrink wrap, solder and bullet connectors is all I used to put it all together.





I plan on also using a usb car charger wired to bullet connectors to use to charge my iPad. But I will get to that later.

I also purchased a voltage monitor for the battery but it turns out it doesn't have the power saving mode that it said it had so leaving it connected to the battery at all times is just a waste of juice. I am just using istat menu to get the batteries voltage.

 

[Chipg]

Well I finally got around to putting together my battery. It was quick and easy and works great so far! I have not tested out how long it lasts yet but I will eventually. Here are the picture of it. A little shrink wrap, solder and bullet connectors is all I used to put it all together.

View attachment 346615

View attachment 346616

I plan on also using a usb car charger wired to bullet connectors to use to charge my iPad. But I will get to that later.

I also purchased a voltage monitor for the battery but it turns out it doesn't have the power saving mode that it said it had so leaving it connected to the battery at all times is just a waste of juice. I am just using istat menu to get the batteries voltage.

Nice! What size battery did you end up getting?

EDIT: Sorry, I see in the pic it says 5000 mAh