HOT Minty boost!?

[speedracerbubba]

Did you use 4 alkaline AA batteries with the first kit, or just 2? If you used 4 fresh alkaline batteries, you very well could have hit the poor chip with 6.5V, which is 2V more than it was meant to take.

Sorry for the confusion, I used the kit exactly as it came with 2 batteries.

I do have an update and some advice (which will hint to my update). The space I work in the garage is lit by a single fluorescent tube and not very well lit. After not seeing anything wrong in the garage I took it outside in the bright sun and was able to spot 1 leg of the diode was 1/2 soldered, so I took it back into the garage and after heating up the iron properly soldered it up and it seemed to not go up a degree with no load after minutes went by (with an output voltage of 4.99 using my fully charged eneloops which were both 1.365volts).

The problem with mine was me and my crappy observation skills (at least I still have my numchuck skills). With my blackberry curve plugged in for about 5 minutes the chip didn't even get hot and I think the warmth it had was from me constantly touching it to feel how warm it was. I have absolutely no reservations about putting this into a small container like the altoids tin after seeing how it is supposed to work when done properly.

Great kit and I am glad I bought 2 (kinda wishing I had bought 3; that pcb is nice)

[mcotis]

Hi all.
I just finished making two MintyBoosts...
Great kit!
Unfortunately my first one is misbehaving. The IC gets too hot!
I was worried about making the second one, but decided to make it anyway.
The second one works fine. IC is warm, not hot.

So back to the first one... Any other suggestions beside checking for shorts?
Voltage wise everything checks out: 2.5V in (2x NiMH batteries) and 5V out...

[adafruit]

post clear photos of top and bottom

[mcotis]

Here are some close ups...
http://gallery.me.com/mcotis#100268

[adafruit]

Here are some close ups...
http://gallery.me.com/mcotis#100268

you have many cold solder joints
redo all of them

[adafreak]

my minty boost was soldered all correctly without any joints touching and gets frickin hot when i put batteries in!
I am using two AA Energizer batteries (pile alkaline 1.5v) Whats wrong with it??? posting.php?mode=reply&f=15&t=7620&sid=a8a392748703b9bd94ab3c49b660758d#

[adafruit_support_bill]

Post photos, front & back.

[rj44319]

Chip in backwards?

[Frank39]

Hello,

I´m here with the same problem.
I also orderd a minty 3.0 kit and I have it already soldered. When operating with two NiMh batterys the chip gets really very hot.
Tomorrow I can show you pictures of it.


Greets,
frank

[adafruit_support_bill]

Hi Frank,

How hot is hot? Are you getting the correct voltage outputs?

From the FAQ:

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

Its 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 dont hear a sizzle (of the water boiling away), its 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.

[Frank39]

Hi,

it´s getting really hot. You don´t want to touch the chip because you will burn your finger. I think this should not be normal.
And yes, I get all the correct voltage as shown in your assembly instructions on the minty-boost site.
This evening I will take some photos and show you tomorrow.

Thanks,
Frank

[adafruit_support_bill]

Does it get hot just by itself? Or only when charging a device?

You don´t want to touch the chip because you will burn your finger.

That is not unusual. If it is not hot enough to boil water it is still within spec:

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 dont hear a sizzle (of the water boiling away), its just fine.

[Frank39]

it´s just getting hot when charging, but not that much hot to boil water ...

maybe it´s possible to mount a heat sink ?

[adafruit_support_bill]

t´s just getting hot when charging, but not that much hot to boil water ...

That is normal then.

There are heat-sinks designed to glue on top of IC's with thermal epoxy. It isn't necessary, but certainly would not hurt.

[T-Prime]

I'd first like to say that this is a fantastic product and an ideal first project. Although I am having a heat issue when I charge my phone (LG Optimus One). I didn't have the issue at first (perhaps I just didn't notice) and my multimeter gave good results when I tested it. Anyway, here are some pictures of my circuit for your review. I should also mention that I'm using 2x2000mAh Energizer rechargeable batteries. The batteries are new and fully charged. And finally if the soldering in the pic looks a little dull, it's because of the lighting. I assure you they are smooth and shiny in person.