#What is power to go 8 full#

Some battery banks actually state two capacities at both voltages, which makes your job easier.

In the end, you can roughly estimated the “actual” battery capacity of a power bank for charging devices at about two thirds of the capacity stated at a 3.7V nominal voltage. Converting the chemical energy in your power bank to electricity and back to chemical storage will dump some of it as waste heat. On top of this you have to consider that there is no such thing as lossless energy conversion.

#What is power to go 8 full#

That only give us about three full recharges rather than four at best! However, our 2500 mAh phone battery charged at 5V needs 12.5 Wh. Using an mAh to Wh calculator, we see that at 3.7V our 10 000 mAh power bank has 37 Wh of energy. This is the unit your electric bill is measured in and indicates the actual energy used. To see how this makes a difference we need yet another unit, the watt hour (Wh). However, USB operates at a minimum of five volts and so the device will expect to be charged at least at that voltage. Lithium cells have a “nominal” voltage of 3.7 volts. The marketing spin has to do with the voltage difference between the battery and the device’s charging input. It turns out that there’s some mild marketing dishonesty going on here, as well as a measure of overhead thanks to the laws of physics. So if you buy a 10 000 mAh battery and your phone sports a 2500 mAh battery, you should get four full charges out of it, right? The battery inside your smartphone or laptop also has a rating in the same unit. This is a measure of how much electrical charge the battery can hold. Power banks are almost universally rated in milliampere hours, abbreviated as “mAh”. Which is a recipe for disaster! Power Bank Capacity Isn’t Always What it Seems Unbranded, uncertified products may have only some or none of these features. Power banks needs to have several features such as overcharge, overvolt and overheating protection to be considered safe for use. UL certification is probably the most common standard in the USA, with other territories having their own equivalents. So be circumspect about how you handle your new power bank and treat it with the correct level of respect.Īt the same time, you should only buy and use power banks that are branded and have certification from consumer safety organisations. The same goes for being exposed to heat from lying in a hot car window or being too close to a heat source. Being pierced or crushed is one surefire way of causing an internal short and subsequent flameout. However, your power bank’s lithium battery can turn into a dangerous object through misuse as well. The only reason the actual accident rates are acceptable comes down to the host of safety standards and technologies built into lithium devices. That’s what happens when lithium ion batteries go bad. That translates to an explosion or fire, which is pretty serious! You may have heard horror stories about houses burning down from faulty hoverboards or phones exploding in people’s pockets.