iPad charging from 12V DC

Topcat47

Topcat47

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Santa was good to me this year and I have a 128GB 2017 iPad. It is my intention to get Navonics on the device for use on board. I have only 12Vdc on the boat, How do I charge or extend the battery life of the iPad from a 12V power outlet?
 
One solution is to get an in car charger. Don't buy cheap and nasty Chinese Ebay rubbish though. One issue with charging tablets from car chargers is that they can be slow. I made my own by using a DC-DC converter with adjustable volts and amps, charges phones and tablets pretty quickly.
 
Topcat47 said:
Santa was good to me this year and I have a 128GB 2017 iPad. It is my intention to get Navonics on the device for use on board. I have only 12Vdc on the boat, How do I charge or extend the battery life of the iPad from a 12V power outlet?
Click to expand...

Greetings,
you can buy chargers which plug into a cig lighter socket.
Be sure to buy one labelled "2Amps, for Ipads".
The ones for Iphones, Ipods etc don't supply enough current.
The leads are also important, fleabay ones may not pass enough current.
Also the device might not accept full current from an 'unrecognised' lead.

I would recommend buying 2 or 3 fag lighter chargers, and leads, from a reasonable outlet, eg a big Sainsburys, which is a fair compromise between absurd Apple Shop prices and unreliable ebay tat.

England is an easy place to buy stuff like this, be forewarned if you go on an extended cruise..in many countries it's very dear or unobtainable..
 
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Prasutigus said:
Greetings,
you can buy chargers which plug into a cig lighter socket.
Be sure to buy one labelled "2Amps, for Ipads".
The ones for Iphones, Ipods etc don't supply enough current.
The leads are also important, fleabay ones may not pass enough current.
Also the device might not accept full current from an 'unrecognised' lead.

I would recommend buying 2 or 3 fag lighter chargers, and leads, from a reasonable outlet, eg a big Sainsburys, which is a fair compromise between absurd Apple Shop prices and unreliable ebay tat.

England is an easy place to buy stuff like this, be forewarned if you go on an extended cruise..in many countries it's very dear or unobtainable..
Click to expand...

I bought one of these USB devices a couple of years ago, well worth it to check USB chargers. Plenty of similar items on eBay.

https://www.ebay.co.uk/itm/USB-Char...-Battery-Tester-Voltage-UK-Stock/182714215392

I've found several chargers only putting our 0.8A instead of promised 2.1A and some leads reducing output from decent chargers. Paid for itself, though I do have a collection of free low output chargers. Sellers refunded money but didn't want charger back.

I did get a decent 5A 3 output car charger which did manage 1.9A & 1.1A charging 2 devices. Most promising 2.1A output were rubbish.
 
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PaulRainbow said:
One solution is to get an in car charger. Don't buy cheap and nasty Chinese Ebay rubbish though. One issue with charging tablets from car chargers is that they can be slow. I made my own by using a DC-DC converter with adjustable volts and amps, charges phones and tablets pretty quickly.
Click to expand...
I did that. It didn't work. I learnt later that later Apple products don't just require a voltage on the USB pins, they have a signal on the other pins too. I had to buy an IPhone charger socket from eBay designed for the job. Pretty cheap. Bless the Chinese worker.
 
I-pad needs the higher power 2.1 amp 5 volt supply. If you have a 12 volt cigarette lighter type socket the Belkin USB charger like this is OK https://www.amazon.co.uk/Belkin-Uni...306877&sr=8-1&keywords=belkin+usb+car+charger I have this model Belkin two outlet charger which has performed faultlessly, and can just be seen (lit up in blue) in the picture below. There is a substantially cheaper Belkin single outlet model available.
For a more permanent solution you could fit a hard wired USB socket, but would then need to have a switch to turn it off when not in use.

P.S. My I-pad is an old one and it charges from a USB power socket on my computer, which is purely a charging port with no signal on any other conductors. On the boat I have charged it from the Belkin adapter.
This RavPower charger would also be a good choice. https://www.amazon.co.uk/dp/B00Q2GFP4M/ref=psdc_340328031_t1_B00J0NG3Z4
tn_DSCF3764.jpg
 
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nimbusgb said:
Get one of these. Panel Mount 12- 24v in and twin outlets. A much better solution than a cigar lighter plug in device. They rot in a season and are rarely reliable.

https://www.amazon.co.uk/BANDC-Wate...id=1514301804&sr=8-5&keywords=panel+mount+usb
Click to expand...

JohnDL said:
+1. the ones that plug into a 12V socket can also be very difficult to remove.
Click to expand...

Topcat47 said:
Wow that was quick. I’ll try the last solution first.
Click to expand...

Guess my comments about cheap and nasty Chinese crap fell on deaf ears :nonchalance:

Mistroma said:
I bought one of these USB devices a couple of years ago, well worth it to check USB chargers. Plenty of similar items on eBay.

https://www.ebay.co.uk/itm/USB-Char...-Battery-Tester-Voltage-UK-Stock/182714215392

I've found several chargers only putting our 0.8A instead of promised 2.1A and some leads reducing output from decent chargers. Paid for itself, though I do have a collection of free low output chargers. Sellers refunded money but didn't want charger back.

I did get a decent 5A 3 output car charger which did manage 1.9A & 1.1A charging 2 devices. Most promising 2.1A output were rubbish.
Click to expand...

Thanks for helping to make my point :encouragement:

I have one of these too. I once bought three cheap USB double sockets, as above. One output next to nothing, one was reasonable and the other output the full 12v and fried a brand new tablet.
 
Hmm, I hadn’t equated the one I ordered with the comment about cheap Chinese cr@p. I will try it first now. The one you showed would need a waterproof enclosure.

Btw the mains charger supplied with the tablet has no signal wire, only two pins are connected.
 
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Mistroma said:
I've found several chargers only putting our 0.8A instead of promised 2.1A and some leads reducing output from decent chargers.
Click to expand...
My recollection is that the reason for putting out only 0.8A is that it was the standard for USB until a few years ago.

The signalling to tell the device that 2.1A is available (so that it won't overload an 0.8A supply) was developed on an ad-hoc basis, and not all manufacturers did it the same way.

I would imagine that there are a few legacy devices which are incompatible with the average 2.1A charger, and it's not the charger's fault.

As illustrated below, the battery page of my Android phone displays the hours until full "on AC" when connected to a 2.1A supply, and the hours until full "on USB" when getting only 0.8A.

JWJARFj.png
 
PaulRainbow said:
One issue with charging tablets from car chargers is that they can be slow. I made my own by using a DC-DC converter with adjustable volts and amps, charges phones and tablets pretty quickly.
Click to expand...

Zing said:
I did that. It didn't work. I learnt later that later Apple products don't just require a voltage on the USB pins, they have a signal on the other pins too.
Click to expand...

For anyone interested in building their own fast 5v USB charger, there is some information and discussion in this fairly recent thread:

http://www.ybw.com/forums/showthrea...V-or-24V-using-droppers&p=6216878#post6216878
 
Strolls said:
My recollection is that the reason for putting out only 0.8A is that it was the standard for USB until a few years ago.

The signalling to tell the device that 2.1A is available (so that it won't overload an 0.8A supply) was developed on an ad-hoc basis, and not all manufacturers did it the same way.

I would imagine that there are a few legacy devices which are incompatible with the average 2.1A charger, and it's not the charger's fault.

As illustrated below, the battery page of my Android phone displays the hours until full "on AC" when connected to a 2.1A supply, and the hours until full "on USB" when getting only 0.8A.
Click to expand...

Sort of correct. The early USB devices were designed for 0.5A before charging was something to consider. Pretty common to get a limit of around 0.8A. Last time I saw this was when adding an old USB extension to let main charger reach a tablet connected to TV via HDMI. I was expecting it to be a problem but it did extend battery life enough to watch a film. I knew that the old data lead would cause the tablet to drop back to a low charge rate even when supply could provide much more.

However, I was talking about case when you buy a 2.1A charger and connect it to a tablet or similar using a decent lead (usually the original ex. mains charger). If you never get a decent charge rate then the cheapo charger is probably at fault.

The device I mentioned is a very handy diagnostic tool. I had a twin 1/2.1A car charger only putting out 0.8A at best and voltage wasn't great either. In fact, the voltage collapsed completely if 2 devices were connected. Supplier gave a refund when I presented details of the output. Plenty of eBay USB chargers claiming 2.1A output but an awful lot don't get close on either voltage or current.
 
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As an additional suggestion, I am often away on my Sadler 26 for a month at a time and have bought a fairly large battery bank which I charge via the cigar lighter when the engine is running. This bank will charge my I pad twice from nil to ful or my phone five times. I have also bought a transformer to convert 12 volts to 230 and will use this more often for charging things as it is so much faster than just the 12 volts. Hope this helps, Kevin
 
xhurleyman said:
As an additional suggestion, I am often away on my Sadler 26 for a month at a time and have bought a fairly large battery bank which I charge via the cigar lighter when the engine is running. This bank will charge my I pad twice from nil to ful or my phone five times. I have also bought a transformer to convert 12 volts to 230 and will use this more often for charging things as it is so much faster than just the 12 volts. Hope this helps, Kevin
Click to expand...

Yes this battery bank approach is my solution too. It's much more reliable than plugging an iphone or ipad into a cigar lighter socket. I think in the latest ios updateesapple have introduced software that measures voltage into the ipad or iphone and the slightly jiggly (technical term) connection on a cigar socket may not be steady enough so you get the dreaded 'this accessory may not be supported' on the ipad or iphone. A power bank gives a nice steady output, so it may be useful to have one even if your power source ends up being cigar-lighter-socket-to-power-bank then power-bank-to-ipad. I can navigate with the power bank for 48 hours no problem. It's described as 20000 milliamps which doesn't really make sense - is there such a thing as milli-amp hours? £30.
 
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