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| Thread ID: 129296 | 2013-02-15 22:28:00 | Best way to charge 28 tablets without using one 3pin plug for each one. | Newteach (4990) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 1328226 | 2013-02-15 22:28:00 | In a school situation, we have around 28 Android Tablets and we want to charge them up without having to plug in one three pin plug for each one. Have tried one 7usb port hub but it won't charge all 7. Any ideas greatfully appreciated. Have seen a picture of a hub that plugs straight into a 3 pin plug but apparently not NZ available. NT. |
Newteach (4990) | ||
| 1328227 | 2013-02-15 22:53:00 | did that 7 port usb hub you tried have its own (external) power supply or just powered from a computer? | Iantech (16386) | ||
| 1328228 | 2013-02-15 23:07:00 | I thought tablets drew quite a lot of power to charge so a hub would struggle with even one tablet. You might have to find some wall chargers with multiple USB ports that can all give 1A at the same time (assuming they use 1A to charge). Of course, there's no way to charge more than 9 or 10 from one socket as the sockets are only rated for 10A. |
pcuser42 (130) | ||
| 1328229 | 2013-02-16 00:04:00 | I thought tablets drew quite a lot of power to charge so a hub would struggle with even one tablet. You might have to find some wall chargers with multiple USB ports that can all give 1A at the same time (assuming they use 1A to charge). Of course, there's no way to charge more than 9 or 10 from one socket as the sockets are only rated for 10A. Slight error there, 10A sure but at 240V AC. Easier to think of it as 2.4KW or round it to 2KW. USB is 5V to use 2KW would require a 400 amp load, I think one power point can do it. A powered hub is the only thing I can think of but tablets tend to charge very slowy from USB (depending on the tablet in question) due to the 500mA limit on USB 2.0 (in practice you can often draw more). some really don't charge from it at all. I have a transformer TF300 and although the charger has a usb plug the wall charger it plugs into outputs 15V @ 1.2A when connected to the tablet (it supposedly switches to 5V if a normal USB device is plugged into it but I haven't tried) so that's 15W of available power compared to 2.5W on a standard USB port. What type of tablets are they and what voltage does the charger supply ? |
dugimodo (138) | ||
| 1328230 | 2013-02-16 00:30:00 | If each charger drew 1 amp from the mains, and for arguments sake, saying they will be charging at 12 volts, then they'd all be charging their individual tablet at about 20 amps (230 divided by 12)!!! Just get sufficient multiway boards, say 4 x 8's (that is 32 outlets) and use one to supply the other three (leaving 29 sockets free) then plug in the chargers. Your biggest problem would be accommodating all the tablets within convenient cable reach. I wouldn't use cheapie multiway boards though, buy good quality units with a switch, and if charging unattended, possibly an overload cutout in case one charger fails. If you are really worried, use two power outlets (but they'll probably be on the same circuit anyway). Cheers Billy 8-{) |
Billy T (70) | ||
| 1328231 | 2013-02-16 00:50:00 | Slight error there, 10A sure but at 240V AC. Easier to think of it as 2.4KW or round it to 2KW. USB is 5V to use 2KW would require a 400 amp load, I think one power point can do it. Ah whoops. Been a long week... |
pcuser42 (130) | ||
| 1328232 | 2013-02-16 02:24:00 | Also beware the temptation to stack all the tablets on top of each other while they charge, otherwise there might be some undersired thermal issues as well. Sadly, the safest option is to scatter them all around on their own chargers. Messy, time consuming, but safest. |
Paul.Cov (425) | ||
| 1328233 | 2013-02-16 03:49:00 | Maybe Powercrate (www.gizmag.com) - a docking air circulated, programmable, and wheelie portable charger tower - but charges only 25 tablets simultaneously. From X2 computing (www.x2computing.com) in the UK. | kahawai chaser (3545) | ||
| 1328234 | 2013-02-16 04:07:00 | Out of curiosity, what school and what tablets? | Chilling_Silence (9) | ||
| 1328235 | 2013-02-16 04:42:00 | Although it say for iPads, there are lots of options www.pc-security.com |
plod (107) | ||
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