Running Tablet on AC only

Feb 22, 2014
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I Have an Android 4.1.1 Sensis N78 tablet that have a very bad (well that is what I been told in a previous thread in this forum) battery. It keeps tuning off the tablet 5 minutes after I turn it on.

The solution, again as I been told, is to replace the battery.

In the meantime I am wondering if I can run the tablet off the AC adapter without doing any more damage to the tablet?

The reason I ask is that when the tablet is plug into AC it also charges the battery, and I just want to know what harm (if any) it can do to the rest of the tablet?

Plus, I have found that if the recharge cable is not laying 'just right' the connection between the AC and the tablet is lost.

And BTW does any possible problems also apply when I connect to my car via the lighter?
 

leeshor

Senior Member
Dec 27, 2011
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It's hard to say if it will do any damage long term but my guess is no. The cable issue though, is disturbing. Is it the cable or the connector? If the connector I suspect that it will fail and may be a part of the reason it's failing in the first place.
 
Last edited:

Spider

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Mar 24, 2011
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If your tablet really was used/stored/recharged in below freezing (20F) weather as you mentioned in a previous thread, that's most likely why the battery failed so soon. If/when you replace the battery, don't do that again or you'll be right back to where you are now. Extreme cold/heat is very bad for a battery.

In the meantime, there shouldn't be any problem using the tablet while it's connected to the charger. Likewise, assuming you have a car charger that's designed for use with that tablet, connecting to your car via the lighter shouldn't be a problem either.

As Lee pointed out, the cable or connector problem is something you should investigate and correct if possible. If that problem doesn't exist when you use the car charger, it's probably just the cable or the AC charger you'll need to replace.
 

cal67

Senior Member
Aug 4, 2011
180
15
For the cable, are you charging off a usb cable connected to your computer or a usb cable that attaches to a small AC adapter? I had one that did the same "charge on and off" depending on cable position or so I thought. When I connected the cable to my computer, it worked fine. Turned out to be the AC adapter cycling on and off. The connection when I moved the cable was just coincidence.
 
Feb 22, 2014
15
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Extreme cold/heat is very bad for a battery

I had no choice in where the tablet was stored when not in use, but, next winter I should have more leeway to be able to have it kept in a warmer place.

However, all my other battery power devices, also kept in under 20F degrees, did not suffer the same fate.

usb cable connected to your computer or a usb cable that attaches to a small AC adapter

I use both methods and you might be onto something.

I have the tablet connected to the USB port of this computer right now, and while it still "disconnects" if the cable is moved/bent, it "reconnects" right away. Unlike when it connected to the ac or dc adapters when you can twist, bend, or drape the cable in any direction and get (or not) get a connection


the cable or connector problem is something you should investigate

While the cable is the one that came with the tablet, the adapters are not.

The AC adapter is from Wal-Mart and seems to be equal to the Chinese Male Prong adapter that was sent with the tablet (Output 5.0V 1000mA)

The DC adapter is from the Dollar Store and worked with no problem.

In fact the connection problem began when battery issue first popped up.

Besides, I just might get another cable to see if it is a cable or connection problem. If its the former then OK, if it is the latter then getting a new battery that can't be charged is moot.

But, in the end, it was in all likelihood that the colder then usual winter that the U.S. has been having this season took a toll on the battery.


My bad:(

I
 
Feb 22, 2014
15
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After some testing it seems that my cable problem is really an adapter one.

But, that will have to be put on hold till I get the battery replaced.

Which leads me to ask 2 last (for now!) questions.

First, where do I get a battery?:confused:

I have tried google, but after wadeing through page after page all I can find is onw site that offers "an excat replacement" battery. But, while the votage and apperence is the same as the orginal (see photos) the amps are not. The "replacement" puts out 2700mA while accourding to the Sanei N78 feature page the battery should put out 3500mA. Does 800mA make that much a difference?

$P0000006.JPG
$P0000005.JPG

Second, how do I install it?:confused:

The battery seems to be glued to a metal panel, and I am worried that if I pull on it too hard, or use heat/slovent on the glue the screen or some other part of the tablet will become ruin.

And that would spell the end of this tablet.

Any help would be appreated.
 
Last edited:

Spider

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Mar 24, 2011
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The "replacement" puts out 2700mA while according to the Sanei N78 feature page the battery should put out 3500mA.

There's no danger of damaging anything with a lower mA rated battery. The only problem is it would only last roughly ¾ as long between charges. (2700/3500=0.77 or 77% the capacity of the original battery.)

Second, how do I install it?:confused: The battery seems to be glued to a metal panel, and I am worried that if I pull on it too hard, or use heat/slovent on the glue the screen or some other part of the tablet will become ruin.

That's trickier, no way to tell what they used to paste it down. As you already know, proceed carefully whatever you try. It doesn't appear to be attached to the circuit board, I'd try prying first. Good luck!
 
Feb 22, 2014
15
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Thanks for the advice, but, I just wonder why when I do see a "replacement" battery for this Tablet the output is always lower then what the company states the battery should be.

I never have seen a replacement battery whos output equals what the company say what the battery output is given as.
 

Spider

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Mar 24, 2011
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My guess is, the companies selling "replacement" batteries make as few batteries as possible to replace all the batteries out there. If it's the correct voltage and will fit in your device, it's the replacement for your battery.
 
Feb 22, 2014
15
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Before I deleated it, this message was going to be if could use a battery with a bigger mA then what in the tablet now.
But, after I was able to remove tha battery form the tablet (using a dinner knive!) I was shocked to see that instead of the factory stated 3500mA battey I had a 2700mA battery.

So, it seems that Sensis lies about what kind of battery thay use. :mad:

But, it does answer the question of why after stateing the tablet will work for 4 hours using Wi-Fi, it lost power at the 1 hour mark.

I am going to try to see if I can get a 3500mA battery (in the right physical size) or if I am stuck going back to a 2700mA battery.

However, this episode does make me wonder how many other of the "cheap" tablet makers do the same?
 
Last edited:

Spider

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Mar 24, 2011
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The new battery must be a 3.7V. The higher the [FONT=arial,helvetica][SIZE=-1]mAh, the longer it will last per charge, so get a larger one if possible. Just be sure it will fit into the case of your tablet.[/SIZE][/FONT]
 
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