Step 2: Build the Minty Boost kit

Picture of Build the Minty Boost kit
First build the MIntyBoost kit according to its instructions. It's really easy to assemble- even a complete novice can do it.

Instead of connecting the battery holder in the kit, we're going to solder a JST connector to the MintyBoost PCB. This tiny connector will then allow the MintyBoost circuit to connect to the Lithium Polymer battery charger circuit. Make sure you get the polarity correct!

Test the MintyBoost by connecting the battery pack (make sure the battery pack has a charge) and charger circuit. The MintyBoost connects to the connector marked SYS on the charger board and the lithium polymer battery connects to the connector marked GND.

Now cut a notch in the Altoids tin for the USB port and use some double sided adhesive to mount the PCB to the Altoids tin.
pfricks4 years ago
Keep in mind that the iphone & battery was not made for extreme heat
Honus (author)  pfricks4 years ago
Sorry but I don't understand your comment. Could you please elaborate?
wher is a circuit diagram?
Honus (author)  arvindhimalayan6 years ago
Have a look at the FAQ section- at the bottom of the page there is a link to the LiPo charger and MIntyBoost web pages that have all the data sheets and circuit diagrams.
this is also basically the same jst cable just a different color http://www.sparkfun.com/commerce/product_info.php?products_id=8670
Aeniph6 years ago
I like this post. For two reasons, one, I did the same thing a couple months ago except I got the 6000 mAh battery from Sparkfun, the one with three cells, and I integrated the whole thing into a backpack, and two, it's really really quite well done. Good job :)
arjunface6 years ago
The 2-pin JST jumper cable is out of stock on SparkFun's website. Can I just by a cheap rechargeable battery and just use the wire?
Honus (author)  arjunface6 years ago
Use this cable- just cut off the end you don't need:

Do you know where i can get a MintyBoost kit? or the Lithium battery charger/ battery itself? Other than the Internet i mean. Radio Shack doesnt seem to have even heard of these before. thanks!
IDSKoT6 years ago
Looking at this schematic for the charger, it doesn't say the wattage of any of the resistors or the volts of the capacitors, and I have no clue what SJ1 is supposed to be. Any help?
Honus (author)  IDSKoT6 years ago
For resistor watt values figure that a max input of 7v and max current of 280mA equals 1.96 watts so I'd imagine using 2 watt resistors or higher would be fine. Since the max voltage is 7v, I would think a capacitor rated at 10v would be fine. As for the mysterious SJ1, if you look at the photos of the charger PCB, that looks to be a trace gap jumper- you flow solder across the two pads to join the PCB traces (for what reason I don't know). It looks like it would tie the USB in to the 5v in so that maybe you would use that if you had a USB connection that you wanted to exceed 100mA input current. I'd ask the Sparkfun guys- their tech email is: spark@sparkfun.com The charger board I have is the previous version and it doesn't have that on the PCB.
samkim Honus6 years ago
Hi Friends, I am new to this forum, well I am trying to make a Li-Ion charger using Max 1555, has any one tried out doing this, if so please do tell me, I have been unsuccessful many a times doing this experiment. I am enclosing the circuit used for this experiment.I have done all the circuit connections as shown in the diagram but still when the battery has been charged after being discharged till 3.55V, while charging the LED will be in ON state, when it reaches the maximum(4.15V), the LED has to turn off, but in my case it remain to be ON. Could any one know the exact reason behind this.I am using DC input instead of USB for charging.Is it okay with it.Thank You.
bpappin samkim6 years ago
Battery charges can be hard, even if you have the circuit diagram. The circuit is very important and directly related to the type of battery.
Honus (author)  samkim6 years ago
Do you have a circuit diagram?
i love the idea but i was hoping i could pull off something simaler without having to buy that minty boost thing any ideas?
yep. You can build the kit from scratch, choosing to leave out any of the unnecessary parts.

the minty boost project is based primarily on the LT1302 sample 5V output circuit (with 2 additional pull up resistors for iphone rondoness) schematics for both are available...also some people like to use a female cable adapter instead of just the socket (gives a cleaner cut for the tin)