Frequently Asked Questions

It works! But then the iPod/iPhone/device gets drained...what's up?

This is a common problem with iPods/iPhone/iTouch. These devices have very large batteries and they have an annoying bug that if they -think- they're being charged they'll stay on and not 'go to sleep' conserving power. That means that if the AA batteries die before the device is done charging, the device will stay on at full power because it thinks it is plugged into the wall. This can cause it to drain the battery. The best suggestion is to use fresh/charged batteries and don't leave it plugged in overnight.

This is especially true of iPhones, as they suck out all the battery power in a little less than an hour in order to 'quick charge'. This reduces the capacity of the batteries, but means that your phone will be up and running faster.

Once you see the charging icon change from a plug, the mintyboost is 'dead' and you must unplug it. For more information, see the user manual.

How come my iPhone/iTouch doesn't completely charge?

iPhone/iTouch's have batteries that are so large there is no way to fully charge them on 2 AA's. You can only charge 1/2 of a battery because the AA's will die before finishing. You should use the Mintyboost to 'boost' it, but not as a way to fill the whole battery to full.

Will the MintyBoost charge my device?

Very likely! Check out our compatibility lists for more information about your favvy gadget. If you find a new device that it does/doesn't work with, please post on the forum or contact us (thanks!)
Nearly all USB-charging devices and any device that charges with 5V power (up to 500mA+ with v2 or v3 of the kit) can be used.

If you are having problems with your device, see the other FAQ's below.

ARRGH! It doesn't work!

Don't panic! Post to the forum (don't send email) about your problem.

A high resolution photo of the top and bottom of your kit will be extremely helpful in debugging your problem.

I get the right voltages but it doesn't charge my favorite gadget! Is the kit a "USB Specification" Charger? If not, how can I make it into one?

Some devices will only charge from 'dedicated USB spec' charger. You may want to convert your Mintyboost to a 'USB spec' charger, which is very simple to do, follow the instructions here on how to do it. This mod will work on any MintyBoost version (v1 v2 or v3) Then try again!

Can I buy a pre-made/pre-built MintyBoost?

We don't sell assembled MintyBoosts, only kits. However, if you post on the forum, people sometimes offer to sell manufactured kits at low cost.

What does the MintyBoost kit come with?

The kit comes with a PCB and all components necessary to build the kit. It does not come with an altoids tin or tools or batteries. The tin isn't necessary but MintyBoost is designed to be placed in one for protection and aesthetics.

How many charges/hours of use can I get out of a MintyBoost?

This question is hard to judge because every device has different power usage. However, a simple way to calculate approximate run-time is: take the size of the internal Lithium-Ion battery (for example, many iPods have 750mAh batteries) and divide 1000 by that number.
So for a 750mA battery, 1000/750 = 1.3
The MintyBoost will fully charge the device about 1.3 times, as a best case.

Remember, this is only an approximation and has a lot to do with the quality of the batteries you use (expensive alkalines v. cheap rechargables) and the internal circuitry of the device for recharging the battery.

For a detailed mathematical analysis, check the user manual under "How many recharges will I get?"

I want better performance, should I attach 3 or 4 AA batteries? How about a 9V?

Check out our detailed battery power tutorial!

OK but what if I want 4 AA's, 2 sets of 2 in parallel?

Check out our detailed battery power tutorial!

When I use the kit, the chip/batteries seems warm or hot...Is this OK?

It's normal for the chip and batteries to be warm or hot, especially when charging a device that is nearly drained. The chip should not get hot or very warm when nothing is plugged in.

The maximum temperature for the mintyboost chip is over 100 degrees C, that is hotter than boiling water. If you are worried, lick your finger (a little) and touch the tip of your finger to the top of the LT1302 chip. If you don't hear a sizzle (of the water boiling away), it's just fine.

However, if the batteries are so hot that its painful to touch, start to smoke, burn or melt or leak fluid....something is wrong! Unplug it immediately and remove the batteries if it is safe to do so.

But it's really hot and I'm worried!

Yes, this is normal. When the chip is working to charge your gadget, it's going to get hot. Normally you never get to see or touch the chips in your chargers so you don't realize how hot electronics get.

Really, it's normal for the Mintyboost to get hot!

If you're concerned, you can always do the finger test above. If it's too hot, it will sizzle, otherwise, it's OK.

When I plug in a device, sometimes theres a 'hum', 'hiss', 'squeak', 'whine', etc this normal?

Yes, sometimes the inductor resonates with the boost converter and that resonance leaks into the audible range. While it's not good for it to always vibrate, it does happen occasionally and is not harmful to the charging device. you can try moving the inductor a little with your finger but the noise is electrical in nature so it's hard to stop completely.

Another thing is that it depends on how much power the device is drawing and what kind of batteries are inside.

If this is a charger, why are the data (D+ and D-) lines used? Why doesn't the 3Gs work with the Mintyboost v2, but the older iPhone does? What are the pullup/down resistors used for, and which should I use?

We have a full tutorial all about Apple gadget charging, check it out!

Does the v1.x work with iPhone/iTouch? Does the v2.0?

Version 2.0 pretty much works with iPhones/iTouch devices but the v1.0 cannot because it is not powerful enough. To get it working you will need the LT1302-5 which can provide 500mA (compared to 200mA from the MAX756).

We have a full tutorial all about Apple gadget charging, check it out!

Can I convert a v1.x kit to a v2.x? Can I use a MAX756 in a v2.x or a LT1302-5 in a v1.x?

No, they are completely different designs requiring new PCBs are components, they are not drop-in replaceable at all.

Why doesn't the v1.2 kit come with R1-R3 and LED1

These parts are optional: they are for the low battery indicator. There wasn't enough space to add them to the PCB using through hole parts so they are surfacemount and on the bottom. They're an 'extra' capability which you may add if you feel experienced with SMT soldering.

I'm trying to make/breadboard this kit on my own and it's not working! HELP ME!

It is pretty much impossible to get good ouput from the kit if it is breadboarded. A custom PCB or proper perf-board is essential. Most components cannot be swapped, and must be used as indicated, even if they're difficult to find in your area. All documentation is on the site.

I can't provide any support or help to 'DIYer's because of the time and difficulty in debugging these projects. Please endeavor to work out your project on your own.

Do you have any high rez photos?


Mintyboost® is a registered trademark of Adafruit Industries

This guide was first published on Jun 11, 2013. It was last updated on May 07, 2024.

This page (F.A.Q.) was last updated on Mar 11, 2013.

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