Written by Cambrionix

In this day and age of USB charging it is important, as a customer, to understand why ‘Amps’ matter. It’s beyond the scope of this document to explain what ‘Amps’ are but we will explain why you need to take notice when they are mentioned on charge/sync cart/case specification sheets.

Would you charge your iPad using a Nokia charger? If not, why? Why does it matter?

Cambrionix Ltd, Leaders in mobile technology charging and connectivity, have been doing some research into iPad charging devices and how the voltage and current (Amps) effect this.

Current is often a misunderstood concept. We’ll start off by talking about voltage as it is linked. Many people know it is important to match voltage of a power supply or charger to the product. The product will often say 5V DC. It is important that 5V DC is applied to the product. If you apply too many volts e.g 12V you will almost certainly destroy the product! If you apply too little the product won’t work. If you think of your product as a torch when the batteries are new the torch is nice and bright because they are at the correct voltage. As time goes by the batteries become flat and so the voltage drops and so the torch dims as it is operating at too lower voltage and eventually it will stop working. So the the volts must be correct for a product to work.

Current is supplied by a power supply or charger. A product (e.g an iPhone/iPad) consumes current. It will try and take as much current as it needs. So if a product requires 2.1Amps then the power supply should be able to supply 2.1Amps or more. If the power supply can supply more than 2.1Amps this doesn’t matter as the product will only take 2.1Amps. If the power supply can only supply 1 Amp in this case then either the product will fail to work/charge or charge slowly as it can’t get enough current (or power) to charge the battery. So here charging will take twice as long.

So it is important to match voltage between the charger and device. It doesn’t matter if the power supply / charger can provide more current then the device requires. Providing less current will prevent charging or slow it down the same as a poorly designed charger can also prevent charging or slow it down. Unfortunately, testing for a poorly designed charger requires test equipment that, typically, only electronics labs have. So it is important to use reputable manufacturers.

As an example, an iPad requires a charger which is capable of supplying 2.1Amps at a voltage of no less than 4.97V at the charger connector on the cart/case (when the iPad is connected and charging). Failure to supply this amount of current at the right voltage will extend the amount of time required to charge the iPad battery. This detrimental effect can be easily demonstrated by charging an iPad, from empty to full, with an iPhone charger. An iPhone charger can only supply the iPad with 1Amp (referred to as ’1A’ on most product spec-sheets) so charging times are increased dramatically! This becomes a problem if your iPads cannot be charged in time for their next use (for example, placed on charge at 5pm and not charged by 8am the next day!).

So, in summary, always read the small print and spec-sheet when purchasing charging devices or sync/charge devices and ensure that you are charging at the correct rate for the tablet device you are using.

If a product specification sheet doesn’t show the charging current for the tablet you wish to charge then you should ask the manufacturer for this information. It’s an important thing to consider when purchasing!