How to charge a tablet from dc power supply?

[Gueyog8a7]

I know that the tablet charges via dc but it is with an ac to dc adaptor. How to charge direct from dc source in van?

Can usb be used as I have 2 ports? If so how? I am not sure what connections are needed.

I looked at the ac adaptor last night and it stated, from memory, 1.5a input and 1000ma output. Might have to check that but that is what I remember from looking yesterday.

Usb would be the easiest I guess but if not how to rig it to charge from blade fuse block?

 

[Danke]

 

[robby]

There are dozens of these things on Amazon.

 

[Texas-Mark]

I know that the tablet charges via dc but it is with an ac to dc adaptor. How to charge direct from dc source in van?

.....

Usb would be the easiest I guess but if not how to rig it to charge from blade fuse block?

The big question is - does the tablet charge with a USB adapter (5v) or use some other DC voltage adapter?

 

[TacomaJoe]

You need to take another look at the transformer to read the output voltage. That will determine your charging needs along with the current requirements.

 

[Gueyog8a7]

The big question is - does the tablet charge with a USB adapter (5v) or use some other DC voltage adapter?

If there was already a usb adaptor then why would I have to ask? You think I wouldn't be able to figure to plug usb connector to usb socket?

It has a 3 pin (uk) dc adaptor pictured below.

 

[Gueyog8a7]

You need to take another look at the transformer to read the output voltage. That will determine your charging needs along with the current requirements.

Something like this seems to be what I am after though not sure which barrell size to get or if it will work right to power it given charge requirements? I read a bit online and some post said it could break the tablet if it was the wrong type so want to make sure all will be ok before trying. Also these are the usb ports I have installed.

 

[theoldwizard1]

I know that the tablet charges via dc but it is with an ac to dc adaptor. How to charge direct from dc source in van?

Can usb be used as I have 2 ports? If so how? I am not sure what connections are needed.

I looked at the ac adaptor last night and it stated, from memory, 1.5a input and 1000ma output. Might have to check that but that is what I remember from looking yesterday.

Those specs on that charger do NOT make sense !

The short answer is, you can not do it with a "typical" USB adapter. The simplest solution, done by most "road warriors" is buy a 120V pure sine wave inverter, around 500W.

A DIY setup could be done (more efficient) but it would require a direct (via a fuse) battery connection.

 

[TacomaJoe]

USB won't work for the laptop. Your adapter is making 12VDC at 3A. Your van battery is 12V but is not exact, varies with charging to over 14V, depending on the alternator. Check your laptop to see if a car adapter is available.

 

[mikefitz]

could break the tablet if it was the wrong type

Yes.
12 volts at 3 amps is somewhat unusual for a tablet or laptop.
Options.
Buy the manufactures 'car charger' and plug into a 12v 'cig lighter ' socket,

Panel Mount Cigar Lighter Power Socket - 12V/24V 20A max.

Panel mounted cigar lighter style power socket with max. current rating of 20A. Suitable for 12V & 24V systems. Optional panel & pod mounts available.

www.12voltplanet.co.uk

Plug the existing charger module in to a small inverter connected to your 12v battery,

Victron Phoenix Pure Sine Wave Inverter - 12V 250VA (VE.Direct-enabled)

Victron Energy 12V 250VA professional, high efficiency, pure sine wave inverter with VE.Direct interface. For caravans, motorhomes, campervans, boats.

www.12voltplanet.co.uk

Make up a lead for a 12v stabilised power supply,

Victron Energy Orion-Tr DC-DC Converter 12V-12V 9A (110W) - Isolated

Victron Energy Orion-Tr 12V-12V 9A isolated DC-DC converter. A compact & fully-featured voltage converter for stabilising a 12V output from 12V battery systems.

www.12voltplanet.co.uk

https://www.sunshinesolar.co.uk/Item/EB-12VREG3A

Make up a lead and run direct off your battery.

DC5521 to Screw Terminal Connector DC Power Jack 5.5mm x 2.1mm | eBay

It features a screw fastening and free soldering, and is designed to fit a 5.5x2.1mm size. This connector is perfect for a variety of applications, from DC power to LED lighting. It is easy to install and provides a secure connection.

www.ebay.co.uk

Buy a tablet that charges off a USB port, most have this charging method.

 

[Texas-Mark]

Those specs on that charger do NOT make sense !

Why do you say that? I have plenty of wall warts with similar specs (wide input voltage range like that)

Yes.
12 volts at 3 amps is somewhat unusual for a tablet or laptop.

I have at least two tablets that take 12V. Just because the adapter is capable of 3A does not mean the tablet will charge at that rate.

Buy a tablet that charges off a USB port, most have this charging method.

Why? I assume his van is already 12V, so he could probably get by without any adapter. I've never seen a laptop or tablet (unless it was 5V USB powered) go up in smoke over a volt or two.

 

[SparkyGage]

I'm on team Danke/Texas-Mark

Question: Is this a tablet like an iPad or Galaxy or is this a Tablet PC?

• If it is a standard "tablet" like and iPad or Galaxy, it charges off of 5v with a minimum amperage 2a or more usually.
• If it is a Tablet PC running windows, you will need to buy the 12 adapter that is mainly a cord with a cigarette plug on one end, a fuse, a regulator (hopefully, but not always) and the correct PC plug on the other end.

Observation1: If you will post the make and model of your device, we can give you better information.

Observation 2: If the port that you charge the tablet from can be connected with a USB plug on the other end and charge from a computer, than the adapters shown above will work fine (assuming they aren't cheap junk, in which case they will fry whatever is plugged into them - but its a pretty simple circuit.)

Voltage: Ideally you want as close to needed voltage as possible, but +/- 5% is rarely an issue with these devices and they will not charge if the voltage is out of spec - the charge controller is ON THE DEVICE.

What IS critical is that the charge source can SUPPLY the MINIMUM amperage. Note, the source is NOT PUSHING the power, it is supplying the power the device is PULLING and the device decides what it will try to pull. So a 1a source can burn up a 2a device's charge circuit (strange but true) , but a 5a source will only supply what the device asks. I charge 2a and less devices on a 4a source (ie "charger") regularly.

(My credentials: I've worked in Healthcare IT the past 20+ years and currently have about 40 such devices, not counting my kids, that I am responsible for. )

 

[Supervstech]

Why do you say that? I have plenty of wall warts with similar specs (wide input voltage range like that)

Likelybecause it specifies 1.5A input, and 3000W output...

 

[wholybee]

Any newer tablet charges via the PD or QC charging standard. These standards use a USB connector but there is a 2 way data communication between the tablet and charger, and they negotiate a voltage up to 48 volts(not that high for a tablet, but the standard supports it). This allows higher wattage and faster charge rates with low current and the thin wires. I think a tablet would use up to 20V.

Note there are 2 standards, and different devices might use one or the other. So it is best to get a USB socket that supports both QC and PD, unless you know exactly which you need.

You can technically charge with a normal 5V 1.2A or 3A USB charger, but possibly the tablet will run the battery down faster than it can charge, and it might take a couple days to achieve a full charge. Unless the tablet is really old and not very powerful, you really *NEED* a charger that is PD and QC compliant.

Understanding that every suggestion so far will either not work, or result in very slow charging. Amazon sells USB sockets similar to those posted previously, but be sure to include PD and QC in the search terms. They are cheap, and made exactly for what you want to do.

There was also a few posts about laptops. The better laptops now do support powering the laptop via PD and a USBC or thunderbolt port. This is great if you have a USB port with PD in a vehicle, you don't need any special power supply, just use a USB cord to plug in the laptop. It you have a laptop without PD, then you can buy 12V laptop adapters.

A sample of a QC/PD USB socket:

https://www.amazon.com/Charger-Socket-Type-C-Waterproof-Motorcycle/dp/B0C596Y4SV/ref=sr_1_3?th=1

 

[Texas-Mark]

Likelybecause it specifies 1.5A input, and 3000W output...

It says 3000mA output not 3000W. As for the input current rating, no idea. I never pay any attention to that as all that is really relevant is the output voltage and output current capability.
The bottom line is we know the tablet is looking for a 12V input, and that is all that really matters.

 

[Gueyog8a7]

Those specs on that charger do NOT make sense !

The short answer is, you can not do it with a "typical" USB adapter. The simplest solution, done by most "road warriors" is buy a 120V pure sine wave inverter, around 500W.

A DIY setup could be done (more efficient) but it would require a direct (via a fuse) battery connection.

The inverter method is silly to me. Why would you go to ac and back to dc when it is already dc.

So how would the DIY setup work? Is it just a case of getting the right size barrel connector to plug to the laptop and stripping the wires and adding terminal connectors and connecting to the fuse block, with fuse?

 

[Gueyog8a7]

I'm on team Danke/Texas-Mark

Question: Is this a tablet like an iPad or Galaxy or is this a Tablet PC?

• If it is a standard "tablet" like and iPad or Galaxy, it charges off of 5v with a minimum amperage 2a or more usually.
• If it is a Tablet PC running windows, you will need to buy the 12 adapter that is mainly a cord with a cigarette plug on one end, a fuse, a regulator (hopefully, but not always) and the correct PC plug on the other end.

Observation1: If you will post the make and model of your device, we can give you better information.

Observation 2: If the port that you charge the tablet from can be connected with a USB plug on the other end and charge from a computer, than the adapters shown above will work fine (assuming they aren't cheap junk, in which case they will fry whatever is plugged into them - but its a pretty simple circuit.)

Voltage: Ideally you want as close to needed voltage as possible, but +/- 5% is rarely an issue with these devices and they will not charge if the voltage is out of spec - the charge controller is ON THE DEVICE.

What IS critical is that the charge source can SUPPLY the MINIMUM amperage. Note, the source is NOT PUSHING the power, it is supplying the power the device is PULLING and the device decides what it will try to pull. So a 1a source can burn up a 2a device's charge circuit (strange but true) , but a 5a source will only supply what the device asks. I charge 2a and less devices on a 4a source (ie "charger") regularly.

(My credentials: I've worked in Healthcare IT the past 20+ years and currently have about 40 such devices, not counting my kids, that I am responsible for. )

I am not sure if this is the exact model but here is a link. I think that is it. It says 7volts. I will have to ask my mum later for the specific model since she is good at keeping receipts so will most likely have the details. That is the closest one I have seen but there are loads of similar models by that company so not 100%.

 

[Gueyog8a7]

It says 3000mA output not 3000W. As for the input current rating, no idea. I never pay any attention to that as all that is really relevant is the output voltage and output current capability.
The bottom line is we know the tablet is looking for a 12V input, and that is all that really matters.

So just connect the wires direct to the fuse block? What fuse would it take? Link above for what I think it is though will get confirmation later.

 

[Gueyog8a7]

Any newer tablet charges via the PD or QC charging standard. These standards use a USB connector but there is a 2 way data communication between the tablet and charger, and they negotiate a voltage up to 48 volts(not that high for a tablet, but the standard supports it). This allows higher wattage and faster charge rates with low current and the thin wires. I think a tablet would use up to 20V.

Note there are 2 standards, and different devices might use one or the other. So it is best to get a USB socket that supports both QC and PD, unless you know exactly which you need.

You can technically charge with a normal 5V 1.2A or 3A USB charger, but possibly the tablet will run the battery down faster than it can charge, and it might take a couple days to achieve a full charge. Unless the tablet is really old and not very powerful, you really *NEED* a charger that is PD and QC compliant.

Understanding that every suggestion so far will either not work, or result in very slow charging. Amazon sells USB sockets similar to those posted previously, but be sure to include PD and QC in the search terms. They are cheap, and made exactly for what you want to do.

There was also a few posts about laptops. The better laptops now do support powering the laptop via PD and a USBC or thunderbolt port. This is great if you have a USB port with PD in a vehicle, you don't need any special power supply, just use a USB cord to plug in the laptop. It you have a laptop without PD, then you can buy 12V laptop adapters.

A sample of a QC/PD USB socket:

https://www.amazon.com/Charger-Socket-Type-C-Waterproof-Motorcycle/dp/B0C596Y4SV/ref=sr_1_3?th=1

This one is not new, depending how many years old you define as new. It is about 5-6 years old.

It doesn't charge by usb that I can tell. There is only the 3 pin plug linked earler. I tried plugging usb to some smaller thin one on the device but didn't do anything so I guess that port is just an output.

 

[Gueyog8a7]

Understanding that every suggestion so far will either not work, or result in very slow charging. Amazon sells USB sockets similar to those posted previously, but be sure to include PD and QC in the search terms. They are cheap, and made exactly for what you want to do.

Why would direct to battery via fuse block result in slower charging? I thought that would be the most efficient.