MintyBoost v3 and 808 #16 camera: problems

[mcc]

Hi,

From the distributor Watterott electronics, germany I ordered a
MintyBoost v3. I built it successfully. It outputs exactly 5.00 Volts.

I want to use it with my 808 #16 camera (which I use for bird watching, escpecially
crows). If you dont know these cameras, here are some informationally links:
http://www.rcgroups.com/forums/showthread.php?t=1556994
http://www.chucklohr.com/808/

The USB cable I used was the one I normally use to charge the camera when
connected to a PC.

But unfortunately...nothing happens. The voltage remains 5.00 Volts but the camera
does not go into charge mode.

I tried the normal setup and the setup with shortened data lines. No success....

What can I try else to get the camera charged with MintyBoost?

Thank you very much in advance for any help!
Best regards,
mcc

[adafruit_support_bill]

I built it successfully. It outputs exactly 5.00 Volts.

Do you get ~2v on D1 and D2 also? Do you have another cable to try? Due to manufacturing variations and wear, some plug/socket combinations mate better than others.

[mcc]

Hi adafruit_support,

D2? Where is D2?
On the page http://www.ladyada.net/make/mintyboost/parts.html there
is only one D1 for MintyBoost v3 mentioned...
Where do I have to measure

-| angainst ground or
-|> against ground ?

Thank you very much in advance for any help?

Best regards,
mcc

EDIT: OOps sorry...you meant the datalines...not the Diode...
D1: 1.967 Volts
D2: 1.967 Volts
seems to be ok...
It works with another cable YEAH! Thanks a lot...
Remains the question, why the cable, which I use
to charge via PC works with the PC but not with MintyBoost...?

[adafruit_support_bill]

Remains the questons, why the cable, which I use
to carge via PC works with the PC but not with MintyBoost...?

Some plug/socket combinations just mate better than others. Sometimes you can 'fix' a bad combination my gently bending the contacts. But it is usually easier just to use a different cable.

[mcc]

Hi,

still haveing problems...

For a moment I thought that changing the cable does help. It does not. The chargeing process stops after two or three minutes,
if the LiPo is completly emptied. Nominal chargeing time is about 2.5 hours when charged via a PC.
If the LiPo is half filled, the chargeing process will not start.

Voltage levels at data1, data2, and (+) are in the range given in the instructions.

As I understand the battery guide it is possible to add three freshly charged Eneloops AA accumulators without
problems (3x1.4V= 4.2V) to MintyBoost. In hope things would change than, I did this. After a very short
time it smells like "fried PCB" and I removed one battery instantly from the battery holder: The MintyBoost was damn HOT.

After a period I checked it with two Eneloops...well, MintyBoost was still alive and well...lucky me.

But the problem describe above remains.

As described I shortened data1 and data2...it does not work.

The cable works well when used with the PC.

What can I try else?

Best regards and thank you very much in advance for any help!
Best regards,
mcc

[adafruit_support_bill]

Sounds like the camera is trying to pull too much current from the Mintyboost.
Does the Mintyboost voltage drop significantly when you connect the camera?

[mcc]

Hi,

thank you very much for the quick reply to my question!

The overheating problem seems to be fixed: I re-soldered all points and
VOILA! Inserting 3 AA Eneloops works fine without "fried PCB".

The situation itself has not changed unfortunately: The camera does not
recognize the charger. Or in other words: The camera does not switch into
"charge mode" green led on). Therefore no current is pulled -- MinityBoosts voltage
is rock stable at 5Volts.

When switching the camera into "recording mode" and power it by MintyBoost,
the voltage drops to ~4.97Volts.

The internal LiPo of the camera lasts for 40 minutes and has a capacity of about 250mAh.
When completly flat it will take about 2.5hours to fully charge it. I am be far no
LiPo expert, but may be the chargeing current can be estimated on base of these values?
The camera has an internal LiPo chargeing controller...

Thank you very much in advance for any help!
Best regards,
mcc

[adafruit_support_bill]

250mAh is a relatively small battery. That is quite a bit smaller than a typical cell phone battery and the Mintyboost should have no trouble with it.

If you post photos of the front & back of your board, we can take a look for any build issues.

[mcc]

Hi,

it may be that I finally found the reason for the problems I described in my previous posts:
I cut any connection between data1 and data2 to the rest of the PCB and shortened both.
Now the camera goes into charge mode for a short while.
Today I will buy fresh ENELOOPS and will see, whether I can perform a full charge of my camera
then.

In this context one thing came into my mind:
ENELOOPS have a relative stable voltage reading under high load, which implies a relative
low internal resistance. On the other hand -- compared to alkalines, they have a lower overall
voltage of 1.3V in opposite to 1.5V.

The FAQ/Battery Guide does not answer my question....
Using two ENELOOPS gives me the benefit of a low internal resistance with the drawback of a lower
overall voltage compared to using three ENELOOPS with a higher overall voltage and the drawback
of an internal resistance increase by 33% compared to using two ENELOOP cells.
What shall I do?

By the way: I read (in the FAQ or the Battery Guide) that the input voltage to the MintyBoost
should not exceed 5Volts. Furthermore I read that one is allowed to use 4 cells in serial as long
as they are NiMHs and no Alkalines. Freshly charged NiMH often have a voltage of 1.3 or more.
4 x 1.3 exceeds 5Volts. Does that harm?

Thank you very much in advance for any help!
Best regards,
mcc

[adafruit_support_bill]

It is not possible to give a definitive answer. Battery discharge curves will be different at different discharge rates and ambient temperatures. Alkalines designed for high-drain use have lower internal resistance than standard alkalines. But they are pretty expensive when you consider that they are not rechargeable.

Freshly charged NiMH often have a voltage of 1.3 or more.
4 x 1.3 exceeds 5Volts. Does that harm?

Unless you are using C or D-sized NiMH cells, the voltage quickly drops to a safe level under load.