[Aug 7th] Investigation of battery capacity claims. EVO AMZER serious ripoff everyone

anit77 · Nov 19, 2009

Telek said:
3.7V (not 4.7) is what is written on my battery, which is open-circuit full-charge voltage. Operating voltage should be 3.6V for 85-90% of the capacity of the battery.

4.2v is the full charge capacity for a 3.7v cell and 2.9~3.1 is the safe discharge level.

More info can be found here.

When using the phone to charge will this won't matter. I have found several smart chargers online that can be wired to the cheap charger that houses this cell. (most of them are around $20-30) a molex connectors could be used to switch between charging & discharging.

I will have the voltage that the phone cuts off at when I get home tonight.

Edit: The phone did indeed cut off at 3.5v. That leaves quite a bit of power left in the battery. I have read that it's best not to run Li-ion batteries down all the way very often but I figured they'd leave that up to the user.

I'll post the full charge voltage later.

Edit2: Full charge through phone is 4.15v.

d0ugie · Nov 20, 2009

How did you measure that? With the software I get about 4.15 tops on 100% and death by 3.60.

My stuff still hasn't arrived, hopefully soon, itching to start this mission.

By the way regarding whether or not these guys refer to the maximum usable mah number or a wider range, if discharging or charging the battery too far outside this range would damage the thing, then no one could call such a measurement's parameters legit. People are only interested in the usable range and if they are trying to get away with some other range then that, I look forward to exposing those guys.

anit77 · Nov 21, 2009

d0ugie said:
How did you measure that? With the software I get about 4.15 tops on 100% and death by 3.60.

My stuff still hasn't arrived, hopefully soon, itching to start this mission.

By the way regarding whether or not these guys refer to the maximum usable mah number or a wider range, if discharging or charging the battery too far outside this range would damage the thing, then no one could call such a measurement's parameters legit. People are only interested in the usable range and if they are trying to get away with some other range then that, I look forward to exposing those guys.

I used a digital multimeter to see the voltage levels. At phone cutoff I let the phone shut down & took the voltage, after that I put the battery back in and started the phone and verified shut down then took the voltage again. At full charge I basically did the the same & came up with the same as you. Their keeping the the full charge max voltage in a safe range for safety reasons.

All batteries are rated at full usable mah (or AH) unfortunately we don't get the full usable mah from the battery due to HTC's set point. Your test will give us the ability to not only see the full usable charge but if you record the time it take to get to 3.5v along with the time at 3v we will have both sets of numbers to work with.

Telek · Nov 21, 2009

Note that to really get the true cutoff point we need to have leads attached to the battery while the phone is in operation at the point in time when it decides to shut down. Measuring the voltage after the phone has shut down won't tell us the true story.

anit77 · Nov 21, 2009

Telek said:
Note that to really get the true cutoff point we need to have leads attached to the battery while the phone is in operation at the point in time when it decides to shut down. Measuring the voltage after the phone has shut down won't tell us the true story.

Very true. It may be possible to do so but there is not much clearance in there to run leads. That and there is a much greater chance of causing a short if not done correctly. If I were going to do it I wouldn't try it in the phone but in a rig. What do you think?

I am going on the assumption that HTC uses a round number for the cutoff, ie 3.5 and not 3.47.

When I took the 1st voltage it was off for 20sec or more before I got a reading and the cell was already rebounding from being off load. The voltage was 3.54 and I watched it go up to 3.58. After I put the cell back in and restarted it cutoff in under 1 minute and I read the voltage in under 5sec. It was at 3.48 and rebound to over 3.5.

Telek · Nov 21, 2009

anit77 said:
It may be possible to do so but there is not much clearance in there to run leads. That and there is a much greater chance of causing a short if not done correctly. If I were going to do it I wouldn't try it in the phone but in a rig. What do you think?

If you use really fine gauge wire (like 24 or 28) you should be able to wrap the wire around the battery tabs in the phone pretty tightly without any risk of shorting to the next tab.

anit77 said:
I am going on the assumption that HTC uses a round number for the cutoff, ie 3.5 and not 3.47.

We also shouldn't be assuming that HTC uses a voltage at all - they could be going strictly off of % remaining as reported by the battery (like laptops do).

anit77 said:
When I took the 1st voltage it was off for 20sec or more before I got a reading and the cell was already rebounding from being off load. The voltage was 3.54 and I watched it go up to 3.58. After I put the cell back in and restarted it cutoff in under 1 minute and I read the voltage in under 5sec. It was at 3.48 and rebound to over 3.5.

As soon as the load is removed the voltage will jump significantly. Even testing it within a second of removing it will give you a very different voltage than it was at when it decided to turn off. We really need to be monitoring the voltage while the phone is running to know at what point it decides to turn off, but as I mentioned that may not really tell us anything since it may not be a voltage cutoff at all. It'll give us a good enough point though that we can do consistent testing on the battery rig.

anit77 · Nov 22, 2009

Telek said:
If you use really fine gauge wire (like 24 or 28) you should be able to wrap the wire around the battery tabs in the phone pretty tightly without any risk of shorting to the next tab.

I have some battery tabs I'm going to cut up into thin strips. My problem is the multimeter I have just has pointers... If the tabs fit I'll solder leads to them then I can wrap the leads around the pointers.

I'm not sure when I'll get a chance to let the battery run down though. My cable is out here and I'm tethering now, so it's charging...

Edit: I forgot I could change the charge settings.

I should have numbers tonight

Telek · Nov 22, 2009

Better make sure you're on the latest ROM then if you're tethering

anit77 · Nov 22, 2009

Telek said:
Better make sure you're on the latest ROM then if you're tethering

Yup, using aruppenthal's beta2.

Eagerly awaiting beta3.

d0ugie · Nov 23, 2009

All right, got three out of four resistors in the mail, 5, 10 and 15 ohm with a 20 on the way -- along with hopefully the cheap charger and the flowmeter.

I was thinking, if the amp drain goes down as the ohm number goes up, were I to add a second resistor to the circuit, for instance two 10 ohm resistors right next to each other, would the two resistors combined behave as a 5 ohm or a 20 or something else? Afraid even the 20 ohm will be too heavy on the batteries to yield fair results but don't want to spend more money ...

Telek · Nov 23, 2009

d0ugie said:
If the amp drain goes down as the ohm number goes up, were I to add a second resistor to the circuit, for instance two 10 ohm resistors right next to each other, would the two resistors combined behave as a 5 ohm or a 20 or something else?

Running resistors in series will increase the overall resistance (simple addition) and decrease the overall current being drawn by the circuit.

Running resistors in parallel will decrease the overall resistance (R1*R2/R1+R2) and increase the current drawn by the circuit.

So for example 2x10ohm in parallel will give 100/20 or 5 ohm resistance. The 5 and the 10 will give 3.333ohm, the 10 and the 15 will give 6 ohm, etc.

With 4 different resistors you can create dozens of different resistance combinations.

Afraid even the 20 ohm will be too heavy on the batteries to yield fair results but don't want to spend more money ...

As it stands the 20 ohm resistor will draw between 175-200mA and take about 8 hours to discharge. That is perfectly fine and I don't think qualifies as too heavy. Even the 10 ohm will be fine. By running the tests with the 5, 10, 15 and 20 ohm resistors you will be able to get a very good idea of the increase in mAh with decrease in load and extrapolate what different loads will offer.

anit77 · Nov 23, 2009

It cutoff at 3.52 on my multimeter and went up to 3.53 and stayed there. I restarted and it cutoff at 3.49 and after rebounded to 3.52 and stayed there, not till after removing the cell did it go higher. Based on the margin of error of the meter 3.5 is within a reasonable range.

It was interesting watching the voltage react to different loads. Of all the different things I tried Google maps put the most drain on the cell. It would drop .05 a volt using it. With opera the load would bounce back and forth based on downloading or not.

d0ugie · Nov 24, 2009

Yay I got the flowmeter. But still no battery charger thing to wire this up.

Hmm.

I wish Macgyver were here, I want to fire this sucker up. Argh.

Now I have to sit through (Jon and) Kate+8 and some pre-finale interview with a Kate sympathizer in exchange for dinner so I'm extra frustrated. C'mon ebay, deliver.

d0ugie · Dec 2, 2009

Game on.

Hey now. Got the final piece, the charger to help me complete circuits. So I've got that, the Flowmeter and four resistors, 5, 10, 15 and 20 ohms on top of course of the OEM battery and the third party battery I bought which puts me in business for this operation.

A little tired to get this rolling tonight but will advise when I have results or questions.

Doug

d0ugie · Dec 2, 2009

Good or bad?

Before I clip off the tips of the ends of the wires of the flowmeter, in the interests of doing this right and not shorting the battery, could one of you please confirm that this is more or less how I want to wire this thing up? The rest of the procedure has been covered, just need help or affirmation about the wiring. Can't see it on the picture but on the flowmeter it has Connect to battery on the left and Connect to charger on the right. I don't know if that makes any difference but I'm guessing that I want the battery side to go to the battery and the charger to the resistor. Also guessing that I want the pair of wires on that side to go to either prong of the battery charger (guessing polarity doesn't matter, red or black) and on the charger side the pair going to either end of the resistor. Like this:

Shall I proceed?

And have we agreed on voltages yet or do I need to test that too?

Doug

Telek · Dec 2, 2009

Ok for the flowmeter "charger side" is the source of the power - "battery side" is the drain of the power. So for our tests you want the "charger side" to be the battery, and the "battery side" to be the resistor.

Second polarity absolutely matters. You need to take apart the battery charger and gut the insides - all you want to keep is the top half of the charger (the plastic) with the 2 battery prongs. Make sure that any circuit board or circutry inside the charger has been removed. You'll then need to determine which is +ve and which is -ve and attach the red to +ve and black to -ve. Reversing this could fry the flowmeter!

If you want wire it up and take detailed pictures and we'll confirm before you plug it in and make it live

d0ugie · Dec 2, 2009

how's this?

anit77 · Dec 3, 2009

Looking at your last pic I can't tell the colors of the wires. What you want to do is connect the +pos to the outer terminal (The right one in the pic) and the -neg to the inner. You can discard the other half of the charger, it doesn't look like the half with the prongs is needed. I would solder your wires & heat shrink or tape up any splices. Also put some tape over the terminals on the housing.

That should be it, you're good to go. On brand new batteries run through 4 or 5 complete charge & discharge cycles before taking any real readings. As far as cutoff voltage goes I feel 3.5v is the number to use. You are going to need to write the numbers from the flowmeter before you disconnect the battery, as soon as you remove it the lcd screen will go blank.

anit77 · Dec 7, 2009

How is it coming along? Have you managed to get any testing done?

d0ugie · Dec 7, 2009

anit77 said:
How is it coming along? Have you managed to get any testing done?

Device was or became defective, never having shown a sign of life either with our testing setup or testing a nine volt (manufacturer said has to be ≥5v). I'm willing to get the fancy thing though I'd like a few bucks shaved off the price so I contacted the seller with this but no response yet:

[SIZE=-1][FONT=Helvetica, Arial, sans-serif]Dear Radical RC,

I bought a Flowmeter II from you to help in a group effort I'm leading to test cell phone batteries made by third party companies claiming dubious capacities for cheaper prices than that of the OEM. Important information to a lot of people and because I may spread negative word about some companies I have to do this testing in an accurate way. In this discussion thread -- http://xdaforums.com/showthread.php?t=583927 -- we came to the conclusion that buying some resistors and your Flowmeter II would be sufficient to clock battery performance. Between that device, some resistors, shipping and handling for everything and a battery charger I bought to gut apart in order to get the Flowmeter hooked up to the battery without shorting anything, I'm out sixty bucks.

Yesterday I started to set up a test, carefully, and to my dismay the Flowmeter never showed any sign of life. We contacted the manufacturer who told us that the Flowmeter has a 5 volt minimum when on your site the description reads that it can be used with a battery "of any voltage" up to 16V and the phone's batteries are 4.2V so if the manufacturer's correct I wouldn't have bought this if you mentioned that on your site.

Instead of asking you for a refund and giving up on this, I would prefer to buy the CBA II from you if you'd kindly give me a discount of what I paid for this Flowmeter II, $32.95, against what you'd otherwise charge for the CBA II, $119. So I'd pay $86.05. I think that's a reasonable request and I hope you agree because this device would be excellent for our purposes. In addition to paying you for most of it, I would also plug your website and this product both on the XDA thread which will get a lot of traffic in addition to my two websites, blownfuze.org and tilt2.blownfuze.org, which get about a thousand uniques a day from people who want better battery life, hobbyists like your customers, and are willing to spend money on these ebay batteries but fear that these companies lie about the performance. It could lead to more sales for you, either for the CBA or some RC saleplanes, whatever, and the device would be used for good.

Would you be willing to do that?

Doug Simmons[/FONT][/SIZE]

[Aug 7th] Investigation of battery capacity claims. EVO AMZER serious ripoff everyone

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