Droid running without battery!

[freezyfreaky]

So last night I put my Droid X on the stock OEM charger left it attached overnight. This morning my battery voltage was at 4256 mV while still attached to the charger.

After rereading Charging lithium-ion batteries more carefully, I noted the following paragraphs:

Li-ion cannot absorb overcharge, and when fully charged the charge current must be cut off. A continuous trickle charge would cause plating of metallic lithium, and this could compromise safety. To minimize stress, keep the lithium-ion battery at the 4.20V/cell peak voltage as short a time as possible.

Once the charge is terminated, the battery voltage begins to drop, and this eases the voltage stress. Over time, the open-circuit voltage will settle to between 3.60 and 3.90V/cell. Note that a Li-ion battery that received a fully saturated charge will keep the higher voltage longer than one that was fast-charged and terminated at the voltage threshold without a saturation charge.
If a lithium-ion battery must be left in the charger for operational readiness, some chargers apply a brief topping charge to compensate for the small self-discharge the battery and its protective circuit consume. The charger may kick in when the open-circuit voltage drops to 4.05V/cell and turn off again at a high 4.20V/cell. Chargers made for operational readiness, or standby mode, often let the battery voltage drop to 4.00V/cell and recharge to only 4.05V/cell instead of the full 4.20V/cell. This reduces voltage-related stress and prolongs battery life.

Some portable devices sit in a charge cradle in the on position. The current drawn through the device is called the parasitic load and can distort the charge cycle. Battery manufacturers advise against parasitic load because it induces mini-cycles. The battery is continuously being discharged to 4.20V/cell and then charged by the device. The stress level on the battery is especially high because the cycles occur at the 4.20V/cell threshold.

Looks like Verizon, for my phone at least, is going for maximum runtime with full saturation and topping it off to keep the voltage around 4.20V. For me, I'm going to try to take my phone off the charger when it's fully charged even though that is not always convenient.

Wondering what voltages other phones/chargers are getting when their batteries are fully charged?

 

[Skull One]

So last night I put my Droid X on the stock OEM charger left it attached overnight. This morning my battery voltage was at 4256 mV while still attached to the charger.

I am really shocked that you are seeing a reading that high. I wonder if the Droid X has a better temp sensor that allows it to see if the heat level needs to turn off the topping charge sooner.

Just for fun, check your batteries ambient temp when it reaches that level again on the charger. I am going to guess it is sub 85F.

My original Droid 1 cut out at 4120 mV like clock work. I haven't checked my refurb I am using now. Guess it is time to check.

 

[freezyfreaky]

So last night I put my Droid X on the stock OEM charger left it attached overnight. This morning my battery voltage was at 4256 mV while still attached to the charger.

I am really shocked that you are seeing a reading that high. I wonder if the Droid X has a better temp sensor that allows it to see if the heat level needs to turn off the topping charge sooner.

Just for fun, check your batteries ambient temp when it reaches that level again on the charger. I am going to guess it is sub 85F.

My original Droid 1 cut out at 4120 mV like clock work. I haven't checked my refurb I am using now. Guess it is time to check.

I will charge my phone overnight and check the temp and voltage tomorrow. Don't believe my phone felt hot when I took off the charger this morning.

Wondering if my phone is an anomaly or other Droid X's are reporting the same voltage on full charge.

Would love to see other people report their findings to see if this is common among all phones/manufacturers.

 

[Skull One]

I will charge my phone overnight and check the temp and voltage tomorrow. Don't believe my phone felt hot when I took off the charger this morning.

Wondering if my phone is an anomaly or other Droid X's are reporting the same voltage on full charge.

Would love to see other people report their findings to see if this is common among all phones/manufacturers.

My wife's Droid X tops out at 4227mv while at 75F. Utterly amazed that Motorola would let it cross the 4.2V threshold.

 

[XanRules]

My D2 gets hot as hell very quickly, FWIW.

Sent from my Droid2 using my thumbs

 

[Skull One]

My second Droid 1 hits 4192mv at 82F.

 

[freezyfreaky]

My second Droid 1 hits 4192mv at 82F.

Your refurb came with a new charger and/or new battery? Curious because you said your old OG Droid didn't come close to 4200mV.

This morning I got 4236mV at 85F. As soon as I unplug the charger, battery immediately drops to 4205mV. Maybe the difference there is the topping charge applied to the battery at the time??

 

[Skull One]

My second Droid 1 hits 4192mv at 82F.

Your refurb came with a new charger and/or new battery? Curious because you said your old OG Droid didn't come close to 4200mV.

This morning I got 4236mV at 85F. As soon as I unplug the charger, battery immediately drops to 4205mV. Maybe the difference there is the topping charge applied to the battery at the time??

I have three motorola chargers in the house. So that is the same. Battery is different from original. In fact the batteries act different in the discharge rate. My old battery would have a near straight line discharge over 18 hours. My current one is closer to a curve that stays top heavy and then suddenly drops off at 50% down to 15%. Even though I get the same 18 hour run.

 

[freezyfreaky]

My second Droid 1 hits 4192mv at 82F.

Your refurb came with a new charger and/or new battery? Curious because you said your old OG Droid didn't come close to 4200mV.

This morning I got 4236mV at 85F. As soon as I unplug the charger, battery immediately drops to 4205mV. Maybe the difference there is the topping charge applied to the battery at the time??

I have three motorola chargers in the house. So that is the same. Battery is different from original. In fact the batteries act different in the discharge rate. My old battery would have a near straight line discharge over 18 hours. My current one is closer to a curve that stays top heavy and then suddenly drops off at 50% down to 15%. Even though I get the same 18 hour run.

Sounds like Verizon or Motorola definitely changed something with their newer batteries. Still curious what other manufacturer's settings are.