Battery full?

First posted
Monday December 9, 2013 05:52
Friday January 10, 2014 09:50

How do they know?

Investigation in progress to let you know how they think they know.

And what is really happening and how to measure it.

Battery empty? And what does charger do? Burned rug prompted this investigation.

Friday January 10, 2014 09:50

Tracfone LG840G display one bar with Onite 1500 mAh battery.

Continued use of phone necessitated replacing the Onite with the 1000 mAh Li-ion battery
which came with the phone.

Battery seen clamped to 9V secured for INNOVA 3320 voltage test.

Initial 4.14V was reduced to 4.12V after a day use.


Onite 1500 mAh charged with Adreama $.99 mobile charger using the Werker 12V 9Ah AGM battery.

Battery Full message display on LG840G caused Patty to unplug cell phone from Adreama.

First case where Battery Full message display with USB charge of LG840G.

Battery died in Patty's Tracfone LG840G so

Video 1.
Video 2.

Sunday January 5, 2014 07:55

Researchers developed an off-vehicle solar concentrator that uses a special Fresnel lens to direct sunlight to the solar cells while boosting the impact of the sunlight by a factor of eight. Fresnel is a compact lens originally developed for use in lighthouses. Similar in concept to a magnifying glass, the patent-pending system tracks the sun as it moves from east to west, drawing enough power from the sun through the concentrator each day to equal a four-hour battery charge (8 kilowatts). 

[Those dead­beat liberal-arts students]

Saturday January 4, 2014 18:51

Holding battery steady while trying to measure voltage technique improved by purchase of Harbor Freight spring clamps one of which is used to secure LG840G battery to 9V battery for stablity.

Transition from 3 bars to 2 voltage measurement of Onite 3.7V 1500mAh battery.

Battery full charge is over 4V.

Three bar Onite charged to battery full voltages.

LG840G 1000 mAh amp retrieved from garage
was cold. Voltage measured.

Allowed to warm to room temperature. Voltage remained the same.

Thna charged to 'battery full' message with wall charger.


Friday December 20, 2013 07:59

Onite 1500 Ah 3.7V battery finally on one bar in Tracfone LG850G..

Voltage 3.66 measured with INNOVA 3220.

Video. Correction: Gray Beans not Onite.

3.7 is nominal voltage.

Second full charge measured 4.21V.

LG840G three beeps at 07:58 indicates battery about dead.

Battery empty warning beep voltage = ?

Thursday December 19, 2013 13:14

Digital timer for 9V NiMH and NiCd charge durations.

Note another free digital multimeter. :)

Timer video.

Correction 9 schedules. 1-9.

Windows 7 Lenovo G560 running xp charging video.

Wind generation of electricity social media script under construction at American Toyota.

G560 power fluctuating between 23-30W at 13:08.


Thursday December 19, 2013 06:37

Battery charge specs:


Harbor Freight free digital multimeter.

This little meter is outstanding! I own a Fluke DMM 179 and of course that meter is top of the line. But would you believe this Equus 3320 is 99% spot on with it's readings when compared to a recently calibrated Fluke 179!! ...

The battery test function (which my Fluke 179 does not have) is the main reason I purchased this meter. The battery test goes beyond just measuring the voltage of the battery any cheap meter can do that all day long. The battery test function in the 3320 puts the battery under a current load (10 Milli amps for both 1.5v and 9v batteries) and then measures the voltage. This gives you a much better idea of if the battery is really good or not and will really perform in your devices. Some batteries on a bare voltage test show good voltage, but that good voltage will quickly drop to unusable levels once the battery is put under load. So testing batteries with a meter that has a battery test function is far superior to just checking it's voltage. This feature alone makes the $19 price for this meter well worth it!
Arrived Tuesday December 17, 2013 by FedEx. Not drone.

Wednesday December 18, 2013 12:59

Battery voltages mesured with inexpensive digital multimeters compels us question

Resistor measurement video first.

4 Band Resistor Color Code Calculator.

4 ? ? ? high precsion resistor.

Voltage accuracy video.

Innacurate meter reason?

Bad battery.

Internet chat, garbage phone call and malware.

Black Op radio and Anita Langley.

Monday December 16, 2013 06:38

Shrink wrap technology replaces black electrical tape and Gorilla tape for USB power breakout devices.

Heat shrink. Amazon.

Heat shrink tubes below have adheasive on the inside. Labelled 'marine' heat shrink.

USB cable wiggled when secured with Gorilla tap. No longer.

Heat Shrink connector cover for DSO Nano 1, 10X probe video.

Heat gun video.

Harbor Frieght heat guns. Amazon.

Almost got montebanked by Electronic Parts salesman to buy expensive heat gun.

BS smelled.[no way to link to odors yet.]

PC boards need to be cleaned after assembly.

Expensive cleaning machines available.

Cognocente advised that home dish washer work as well.

Monday December 16, 2013 11:03

Lead-acid batteries: Monitoring state-of-charge and health.
About the Author Rajakrishnan (Raj) Radjassamy is the Business Development Manager for TI’s Battery Management Solutions where he supports battery monitors, gas gauges and protectors. Raj received his Ph.D in Computer Engineering from the University of Arizona, Tucson. With nearly two decades of engineering experience, he has been awarded nine patents, with another six in review. Raj can be reached at

1 Agressive automotive discharge.
2 Battery full voltage likely indicates automotive battery.

But measuring points are same here.

Was 13.35 at end of charge.

Friday December 13, 2013 14:02

Charging Tracfone LG420G with car charger progress.

Temperature probe attached to 3.7V 900 mAh battery.

1 Start of charge video.

Werker battery voltage minus the car charger voltage times the current flowing into the cell phone battery is the power, measured in watts that the car charger must dissipate.

1kWh = 3412.14163 BTU. Very important number.

Total heat the charge charger must disspate while the battery is charging can be roughly computed.

Thermal coal. "This is an average of 18.8 million BTU per short ton."

Care required when charging batteries to avoid smoke, fire, equipment failure, ... .

"A typical coal-fired power plant works at 10,500 BTU/kW·h, an efficiency of 32–33%."

3412/10500 = 32.495.

2 .41A continue to go into battery.

3 Declined to .26A.

4 Battery full.

5 4.21V at full charge.

Charge circuits cuts-off current to battery when full.
On this phone.

This may not be true for other phones or even different series of the above phone.

Testing a phone is required to make fairly sure. Not absolutely sure, of course.

KillAWatt meter used on this page design was changed because early series where destroyed by modified sine wave input.

Friday December 13, 2013 08:11

Beeps from Tracfone LG840G alerted that Onite required charge Thursday afternoon.

LG840G left on charger over night.

Friday morning

Does this mean that current continued to flow into battery even though it was 'full'?

Request is to unplug charger, not phone.

Battery removed from LG840G. 4.21V measured. 4.21 = 3.7 X. About a 14% overcharge?

Discharged battery storage not a good idea we read.

Harbor Freight about $20 charger set on 2A used to charge Werker.

1 Preparation for charge video.

2 Power on 13.89V.

3 14.34 charge progress.

4 14.45V charge voltage.

5 Charge complete.

Friday December 13, 2013 06:03

Battery full? How does the Tracfone LG420G know?

Battery removed and measured 3.43V.

Importance of paper clip in experiment.


Ready to test.

Thursday December 12, 2013 14:19

USB car charger from Harbor Freight exceed USB specification voltage limits.

$14.88 Tracfone LG420G comes with a car charger so we tested using using 12V 9Ah Werker battery.

0V out. ?

Second charger tested. 0V out.

Hmm. Honda CR-V charger video.

Charger now working powered by Werker video.

5.70V exceeds USB specification limits too.

LG840G 1000 mAh above 900 mAh LG420G battery.

Breakout cable for the LG420G required to test battery charging.

USB cable Materials video.

Magnifying glass required.


Kester #2331-ZX solder flux used. Best flux we found through experimentation.

Black electrical tape was used in the past.

Heat shrink technology used by Jake at Hallmark to cover DSO Nana V3 1X 10X probe was used.

Ground lead shorter than power so that test clips don't short ... easily.

Solar battery charging was initial reason for our investigations.

At about 14.8oF solar water pump panel

We do tend to think that solar panels are going to work very well on a blistering hot summer day. Surprisingly this is actually not the case. Solar panels will lose efficiency in temperatures above 30 degrees. The cooler weather actually suits them better.
Summer max is around 8+V.

Recharged NiMH or NiCd 9V battery powers meter.

Plastic stickem on back of meter contains date and perhaps voltage of battery.

Primary function of meter is to discharge battery so that it can be recharged.
Terk Technology HDTVi VHF/UHF HDTV Indoor Antenna rabbit ear broken. But still worked well.

PBS Channel 5 sometimes does work properly.

Terk FDTV1A Flat Digital Omni Directional Amplified Indoor Antenna-Black arrived from Amazon.

Installed morning of LG402G charger experiments.

Installed with and without amplifier. Marginal, if any, performance improvement over old terk.

Channel 5 problems persisted until antenna properly positioned.

Works better than previous Terk.


And what can go wrong. :(

Charging advice for Onite 3.7V 1500 mAh Li-ion battery.

Readers: Not clear if a mobile device stops charging once it determines the battery is 'full'.

Below videos show that the Harbor Freight charger illuminates green LED and stop current from flowing into charged battery.

Seeed Studio DSO Nano is reported to only have a resistor between USB 5.0 and a 3.7V Li-ion battery.

Monday December 9, 2013 08:36

New charger likley has recent battery charging ICs?

Charging Harbor Freight 12V 35Ah AGM with 2-6 A 120V charger video 1.

Charged video 2.

Charging Werker 12V 9Ah AGM with 2-6 A 120V charger video 3.

Charged video 4.

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