Discussion in 'Asus TF201 Forum' started by graye, Dec 28, 2011.
I've noticed that the AC adapter gets rather warm... is that normal?
Welcome to the forum.
Yes, it is normal. It does have thermal protection circuitry. Sometimes when this is triggered the charger quits working and the fix is to put it in a ziploc bag, place it in the freezer for 20 minutes and it will reset. Happens rarely, but it can happen.
Early versions (pre-July) got extremely hot, too hot to touch. Since then they have been redesigned to be cooler, but still quite warm to the touch.
Great advice, but I'm pretty sure the OP was talking about the Transformer Prime, as mentioned in the thread title.
As for the hot charger - I'm pretty sure this is normal. As Frederuco brought out, this happened with the original Transformer as well. The Prime (and original Transformer) does charge very fast when compared to most other tablets; there's a lot of current flowing through there, and hence more heat than usual.
However, there's no way to be sure as the Prime hasn't really been out for too long. We can only go by the example of the original Transformer until others comment on the issue who actually own the Prime.
Although I did miss the Prime in the title, the TF101 (OG TF) and the TF201 (Prime) use the exact same charger. The Prime may draw a bit more power as it has a bigger battery.
OK, I am jumping in a bit late here and with a slight twist.
Will a Prime charge from a normal 5 volt USB socket or does it have to be a 12 volt power supply?
It would need to be a USB 3.0 port to charge as that is what the Prime's charger is based off of (AFAIK).
Is USB 3.0 12 volts instead of 5 Volts?
I can't confirm for sure but 5V is the de facto standard and I would be really surprised if it required 12V.
I have seen car charges with USB output with 12v instead of 5. One place I saw was selling a Car Charger with a 12Volt USB, labled specifically for the TF201 as he said it needed the 12V and that "5 Volts on the Prime just doesn't cut it" (his words).
When I look at the 110 volt Asus charger it does say it has both 5 volt and 12 volt output.
The Prime (and the other ASUS Eee Pad tablets) will charge from a 5 VDC USB socket or wall charger. The tablet will not show charging. It will only charge with the screen off. I ran some tests on the OG TF (Tablet only). I could not get the dock to charge with a 5VDC charger.
ASUS Wall Wart (15 VDC @ 1.2 Amps) - Charges about 35% per hour with the screen off. Will continue charging (slower) with the screen on.
iPad2 Wall Wart (5 VDC @ 2.0 Amps) - Charges about 10% per hour with the screen off. Will not continue charging with the screen on.
iPhone Wall Wart/PC USB (5 VDC @ 0.5 Amps) - Charges about 3% per hour with the screen off. WIll not continue charging with the screen on.
Also, the ASUS wall wart will detect if it is an Eee Pad connected. If it is not detected it will output 5 VDC @ 2.0 Amps so you can use it to charge your other USB devices.
I noticed that initially the charger got warm, but not alarmingly so. It is normal for the charger to get warm, an indication that it is doing its job. The level of heat is determine by how hard it has to work to charge the battery. Once the battery develops a charged reserve, it will cool down some what.
Perfect answer. Just what I needed.
Sent from my Transformer Prime TF201 using Android Tablet Forum
Invest in the Dynex Universal camera/ camcorder universal adapter. Using the ASUS charging cable, plug into Dynex and you got the best charger for the ASUS possible
You can purchase at Best Buy for $30 or amazon/ebay for $7 or so
I have 2 one for work and 1 for home/no more over heating, nice solid charge, long cord, easy and frustration free
This has been explained, in detail; elsewhere. You need to look at current (amperage) as well as voltage to determine the value of a charger/inverter
I can confirm that this charger will work in the car for Prime (Not just TF201 as listed) Since I had a TF101 and knew that the charger is pretty much identical in output, I figured it was worth a try. I grabbed one because the number of avalable mobile charghers that provide enough power for the Prime are very few indeed...
Note that the first time I used it, I had it attached to the prime, and turned ignition on (My car requires IGN on for lighter socket to be powered.) Nothing... I was about to get pissed off, but decided to try it another way (I do not like the idea of plugging the socket in while cabled, since I want it to be a distinct "Off/On" not a series of on..off...on... as happens when you get a poor connection with an accessory socket. Instead, I kept the socket inserted (it actually has a very solid, strong spring type connection, one of the best, and this the little handle to pull it out with) and just plugges the cable into the socket or into the Prime, I forget which.
Worked fine, and has worked ever since. Note that this is a 12 Volt-2 Amp charger. The stock Asus charger runs two ways 5v-2a or 15v-1.2 amp (not sure what the conditions are, whether driven ny the state of charge of the battery, power on or powered off, or even input voltage... since it is an international charger with separate plug modules.
Bottom line is, that while the pictured charger works, it does charge somewhat faster that the stock provided unit, and faster charging CAN decrease the lifespan of lithium batteries. I think that statement is more geared to VERY rapid charging, not the +50% boosted charging we are seeing here. If you compare 15v-1.2 with 12v-2amp a crude method of multiplication yields 5*2 = 10 (the slower of the supplied chargers methods), 15*1.2 = 18 (The faster for supplied charger) and 12*2 = 24 (the aftermarket car charger) so it's up to you if you are comfortable with charging at 150% of norm. Most modern devices are quite adaptable to varying charge rates, witness the phones in my house that share chargers simply based on connector type (Got a micro USB charger, Dad?) Notice it wasn't "Got a 15 volt, 1.2 amp charger Dad?" LOL!
Again it's all about how precise you like to be, and how much care and attention you want to provide the battery. After my experiment with the 12 Volt car charger, I decided I will probably not use it, even if it works. Knowing that my Prime has a sealed battery, as most Tablets do, I prefer to use a good quality DC-AC inverter and stick with the stock charger. I have 2 converters, one a tiny 150 Watt Belkin, the other a decent 1000 watt (1500 watt peak) that I can use when on the road. But then again, WHY take a Prime on the road? It sure won't be for navigation that's for sure, LOL! Actually I have a TomTom Bluetooth GPS transceiver I got on Amazon for $15, and I tether to my rooted android phone for Wifi, so it's all good.
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