I have an ipad with the external Bad Elf waas capable GPS chip. Works excellent in showing with fairly accurate precision where you are at on your enroute/VFR charts. However, having that chip on and having maximum light output from the iPad display (needed due to the sun and glare) drains my battery very quickly. Therefore, I'd like to use a USB car charger to charge the unit similar to this one ( http://www.amazon.com/Scosche-reVIVE-Dual-Charger-iPad/dp/B003N7NO4Q/ref=cm_cr_pr_product_top ). My question is, can these chargers draw so much power from general aviation aircraft DC receptacles such that they can destroy either the avionics or the iPad? I'm getting about $18,000 in new avionics installed so I'm very cautious...........
The Ipad really doesn't use much current to charge, USB ports normally only supply 500ma to 1amp of power and that is at 5volts so you won't be using very much from a 12v source (or 24v).
Your issue may be finding the right adapter to allow charging at the "voltage" you have available.
Some GA aircraft are 24v and will need a circuit to reduce that to 12v (as most cars have) in order to even plug in a USB charger. An aircraft "DC" receptacle will usually be at the voltage available from the battery/charging system so check to see what that voltage in your airplane may be. Over voltage to the USB charger will burn it out rather quickly. (Like the second they are connected.)
I have been using Fujitsu and other tablets connected to the 12v buss with no issues whatever. Those pull much more power than an IPad. Its not the power available that is the issue in an aircraft, its the voltage that is used when charging a laptop or tablet computer.
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