Lou Stule
3 Argentium

RE: Dell Venue 8 Pro not CHARGING!!!!

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Not clear to me if your tablet is refusing to charge even when indicated charge is under 90% — if so, yeah — that's wrong, but Dell techs may be able to walk you thru a firmware reset which could will prevent a "round-trip to Round Rock." (Sometimes, the firmware can get a bit scrambled after the battery goes completely flat.) Otherwise you can expect to see the charge level drop when connecting a memory stick (or other USB device) since it draws power from the Venue battery while connected via OTG...

Btw — 800 308 3355 — 24/7 

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kcorpetti
1 Copper

RE: Dell Venue 8 Pro not CHARGING!!!!

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Generally, best Li+ battery longevity will occur by keeping charge over 10% and under 90%; but from a practical POV — don't let the battery become fully depleted (flat) & accept the definition of "fully-charged" as when the light goes-out. You might 'tease' a few extra % into it by successively unplugging~replugging the charger or rebooting but that's stressful to both the gear and the guy. Besides, batteries self-gischarge more quickly when fully-charged so those extra few pct-points are quickly lost and just contribute to increased wear. Avoid charging or operating your tablet immediately after it has been exposed to temperature extremes (hot or cold); remove from bag or packaging & allow at least 30 mins to stabilize at room temp before operating. Engineers match a bundled charger to the size of the battery, so the charge will be replentished quickly without overheating the battery; best to avoid chargers with much higher rating than the original — esp. when connecting to a nearly-depleted battery. Most tablets will eventually fully-deplete their batteries if left in "Sleep" (active standby). Whenever you don't anticipate using tab for at least a few hours, better to shut-down manually — esp. when moving it away from its network connection.

So, afer reading all this, I hope you're not sorry you asked! If you're able to follow these guidelines, your battery will want to show its appreciation by lasting 'til the the time when you'll be ready to move-on to more-interesting technology... 

Enjoy!  emoticon.Cool.title

Li+ batteries do not suffer from the memory-effect of Ni-Mh and Ni-Cd, and Li+ BARELY have any self-discharge (about 5%/month). Also, they can well be used from 100% to 0% State of Charge (0% does NOT equal to 0V) without any worries. That's what they're designed for, and thats why everybody's using them. Also, batteries do not "suck in current", they only take what they draw. If you plug in a 50A charger to your Dell, it will only suck in 2A. You cant just "jam" in more than it wants. Thats not how electricity works. If you want to extend the life of your battery, then you should leave it fully charged as long as possible, because Li+ batteries will suffer from a significant loss in capacity after 500 cycles. It is recommended to fully deplete them from time to time, but this is done to avoid any inaccuracies in reading the correct capacity of the battery cell. 

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Lou Stule
3 Argentium

RE: Dell Venue 8 Pro not CHARGING!!!!

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@KCORPETTI: I can see right-off, how fond you are of your own opinions, so I won't waste any effort by attempting to pry you loose from them. However, Jeff (and others) can easily sort-out the science from voodoo in only a few minutes of googling...

"best practices for lithium battery charging?"

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kcorpetti
1 Copper

RE: Dell Venue 8 Pro not CHARGING!!!!

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I see what you're trying to do, but I'm gonna have to ask you to point out what is it that I said that you don't agree with. I agree that I may have come off a little too inappropriate, but everything I read from your google search confirms what I said. 

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swaaye
1 Copper

RE: Dell Venue 8 Pro not CHARGING!!!!

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Also, lectures about battery chemistry and charging practices have little to do with the problem of people being unable to get the Venue 8 Pro to charge.

kcorpetti
1 Copper

RE: Dell Venue 8 Pro not CHARGING!!!!

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True. I apologize for that, but as an engineer is part of my social responsability to correct any misinformation. With that said, it doesnt mean Im always right.

Getting back on subject, I did notice something interesting: my Dell Venue 8 Pro would charge whenever I plug it into my laptop's USB port whenever it's off. It is a relatively new Toshiba laptop with USB Sleep and Charge (USB ports are powered even when computer is off to allow charging USB devices). It is an 3.0 USB port, and the interesting part is that if I turned my laptop on, it would stop charging. When I turned it back off, i'll continue charging. 

I have to add that my Venue 8 Pro accept charge from my laptoo (when turned on) about 25% of the time. This might meen that the USB port signal is significantly different when turned off, even though it still provides 5V on both occasions.  I wonder if there's a way we could force a USB Port to act as "Sleep and Charge" any time while the computer is on...

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dietmd123
1 Copper

RE: Dell Venue 8 Pro not CHARGING!!!!

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This whole charging thing is ridiculous!! I am waiting for the ice to melt here in Atlanta so that I can send my non-chargeable Venue 8 back RMA to the Houston repair center. The block in the charging port is loose and moving all over. Can't charge it at all!!

Got this device Black Friday -- It's been a Black Experience since the first time I tried to charge it!!! Not to mention the Stylus issue. Which is still not resolved!!!

Product was clearly not ready for prime time!!! emoticon.Crying.title

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Lou Stule
3 Argentium

RE: Dell Venue 8 Pro not CHARGING!!!!

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As an engineer, you understand that designing battery powered devices can involve many tradeoffs? Before attempting to "force" a tablet or laptop to do something it wasn't designed to do, perhaps, investigate why it doesn't. In my experience, answer is often more complicated than just because some other engineer was too busy or stupid. Then, if you still choose to apply "force" you'll be less likely to cause harm. Some solutions I have seen posted in forums are downright scary.

(Oh, cr@p! I just typed my 1st post on a Venue 8 tablet, then noticed I had been stabbed-in-the-back by auto-complete — but I then had to go to another computer to access "edit" option for my own post... Now, that IS stupid!)  emoticon.Wink.title

Btw, afaik, none of the Dell employees we "see" 'round here are showing up as part of their day job; it's just a hobby — because they LOVE their company (or, their families are being held hostage). Either way, let's be gentle on 'em... emoticon.Cool.title

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Jeff Leites
3 Zinc

RE: Dell Venue 8 Pro not CHARGING!!!!

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 Also, batteries do not "suck in current", they only take what they draw. If you plug in a 50A charger to your Dell, it will only suck in 2A. You cant just "jam" in more than it wants. Thats not how electricity works.

I don't believe this is entirely correct.   I'm not an expert, just a hobbyist, but I'm sure a resistor will draw a fixed amount of current based on Ohm's law no matter how much current is available.  When it comes to batteries, I think that's a different story (maybe due to the resistance changing during the charge cycle?).   I know very little about LI-ion batteries, but back in the old days, I'd built a few Ni-Cad chargers.  The batteries were labeled with recommended charge rates, usually 1/10 of the current capacity of the battery.  The chargers I made were either constant current chargers, or they had circuitry to drop a higher current rating down to a trickle charge when once the battery reached a certain voltage level.

I'd say that the 2A rating of the Dell charger is the amount of current that can safely be drawn from it without over heating.  The amount of current actually drawn is controlled by the charger.   Just an educated guess.

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JordanMills
2 Bronze

RE: Dell Venue 8 Pro not CHARGING!!!!

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 [quote user="kcorpetti"]

 Also, batteries do not "suck in current", they only take what they draw. If you plug in a 50A charger to your Dell, it will only suck in 2A. You cant just "jam" in more than it wants. Thats not how electricity works.

I don't believe this is entirely correct.   I'm not an expert, just a hobbyist, but I'm sure a resistor will draw a fixed amount of current based on Ohm's law no matter how much current is available.  When it comes to batteries, I think that's a different story (maybe due to the resistance changing during the charge cycle?).   I know very little about LI-ion batteries, but back in the old days, I'd built a few Ni-Cad chargers.  The batteries were labeled with recommended charge rates, usually 1/10 of the current capacity of the battery.  The chargers I made were either constant current chargers, or they had circuitry to drop a higher current rating down to a trickle charge when once the battery reached a certain voltage level.

I'd say that the 2A rating of the Dell charger is the amount of current that can safely be drawn from it without over heating.  The amount of current actually drawn is controlled by the charger.   Just an educated guess.

[/quote]

That's consistent with what some experimenting has shown.  It looks like the charge controller can handle up to 0.8 A at 5.0 V, and won't take any more no matter what load is on the device or how low the battery is.

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