Solar MintyBoost - iPhone 4

[soccerdude71]

Hello,


I recently put the solar MB kit together and am having some difficulties. When the iPhone is plugged in, it either charges for a few seconds then shows that it is plugged in (but not charging) or just shows that it is plugged in. The device is connected to 2 panels connected in parallel that create 6v ~300mA.

The device shows power and charging LEDs, and I have left it out for 3 days to charge (approx 25 hours of direct Southern CA daylight), yet it still doesn't seem to charge correctly.

Any thoughts?


thanks
George

[adafruit_support_bill]

The device is connected to 2 panels connected in parallel that create 6v ~300mA.

Is that what is advertised, or what you measure under actual conditions under load?
Have you tested the components individually? Make sure that the solar panels charge the LiPo with no phone connected. Then test to see if the phone will charge from the LiPo.

[soccerdude71]

Silly question.... What is the best method for measuring current with the mintyboost/solar setup??

[soccerdude71]

Also, the 'PWR' and 'CHARGING' indicators are on when in part/full sunlight.

[adafruit_support_bill]

You will need to disconnect one of the wires between the battery and charger and insert you meter into the circuit.
http://www.electronics-radio.com/articles/test-methods/meters/how-to-measure-current.php

[soccerdude71]

Hello,

Thanks for the response. Please allow me to clarify my last question. I know How to measure current, but what would be the correct points to measure within the kit?

I just measured the current from the panels directly (not under load) and I got right around 290 mA.

[adafruit_support_bill]

To measure the panel output current, you need to insert you meter between the panel and the charger. To measure the charge current, you insert the meter between the charger and the battery. In either case, disconnect one of the two wires connected to the device and insert the meter there. It doesn't matter which wire, because the current is the same on both.

[soccerdude71]

Hi,


I am not being clear Let me try again. Based on the picture here, what would I use as measure points? I have already measured just the panel's current, but I want to measure it under load.

[adafruit_support_bill]

Please refer to the link posted previously for how to measure the current in a circuit.

I just measured the current from the panels directly (not under load) and I got right around 290 mA.

How did you measure that? If your panel was not under load, then the current would have been zero.

If you just put your meter probes across the panel leads, then your meter WAS the load - in the form of a short circuit. You may have had 290 mA going through your meter, but it was probably not at 6v.

To measure the current of a circuit under load, you need to break the circuit and insert your meter into it.

[soccerdude71]

Thanks for all your help.

With the meter across the leads, I get 255mA and 6.5v

[adafruit_support_bill]

With the meter across the leads, I get 255mA and 6.5v

I guess it is me that is not being clear.
That is a valid way to measure voltage, but not a valid way to measure current.

The load presented by the meter is different in current measuring mode than in voltage measuring mode. If you had two meters connected at the same time, you would see that the voltage is not 6v when you measure current that way. If you really had a 6v voltage drop across your meter when set for current measurement, you would probably see smoke coming out of it (!)

Once again. To measure the current under load.
1) connect everything as for normal operation. (panel, battery, Minty & phone)
2) disconnect one of the wires from the panel.
3) set your meter for current measurement and touch the probes to the disconnected ends of the wire to complete the circuit.

[soccerdude71]

Ok, I have it connected properly for measuring current.... With full load (panel connected to MB, iPhone connected to MB) it shows right around 100 mA.

[adafruit_support_bill]

Ok. That looks good.

100 mA is not going to be enough to charge the iPhone by itself. The phone will want at least 500mA @5v. But it should be enough to charge the LiPo.

When the phone is not connected, your panel should recharge the LiPo.
When the phone is connected, most of the current will be coming from the LiPo (assuming it is charged).

[soccerdude71]

Based on the 100mA input from the panel, about how long should it take to charge the battery? Wouldn't 3 days be enough? (24 solar hours)

[soccerdude71]

Also, I did charge the MB via my laptop USB port and it still does the same thing, which is show charging then quickly switches to just a power indicator.