Develop Bugs

about to buy a power bank and need advise

Hi there ,
I'm about to order one in amazon in the next few minutes ,
can anyone recommend on a power bank of 9000-1000Mah?
in addition , if there's one that can be charged and discharged simultaneously.
price should be up to $40.
thanks for your help!

rotman253 said:
Hi there ,
I'm about to order one in amazon in the next few minutes ,
can anyone recommend on a power bank of 9000-1000Mah?
in addition , if there's one that can be charged and discharged simultaneously.
price should be up to $40.
thanks for your help!
Click to expand...
Click to collapse
I would recommend you get a 10000mAh once, you can search it on Amazon, get the high ranking and good reviews one.
Remember with the standard industrial design, you will expect to get 30% conversion loss, so with a 10k mah, you will be able to get 7k mah for charge.

Scroll down to power bank/battery reviews I posted here: http://forum.xda-developers.com/showthread.php?t=2192333

Here i listed some power bank +1000 mAh under $45
Anker® 2nd Gen Astro E3 Dual-Port Ultra Compact External Battery Portable USB Charger Power Bank
10000 mAh, $29.99
Anker® Astro E4 13000mAh Dual USB Portable Charger
13000 mAh, $33.99
Anker® 2nd Gen Astro3 12000mAh (4A Output) Portable Charger Triple USB External Battery
12000 mAh, $45.99
Hopes help
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2000mah power bank portable phone charger

2000mah power bank portable phone charger
Product Specification:
Specification
Capacity 2000mAh
Input 5V/1A
Output 5V/1A
Weight 51
Color Optional
Size 90*57*8
feature ultra slim plastic case
[email protected]
Apply to:iphone,ipad,ipod,MP3,MP4,Camera and other mobile phone
Features:
1.Easy to use
2.Any time for your solution to power trouble
3.Brand new with high quality
4.Easy to charge with different interface accessories
5.Long cycle life, rapid charge
6.Durable with lightweight
7.Safe,reliable and stable, perfect for using on travelling and outdoor activities
8.Enviromental friendliness and economic efficiency
9.Novel design, elegant workmanship and complete in instruction.
Application:
1.outdoor activity: sport, hiking
2.Business gift
3.Staff welfare
Quality warranty and service:
1.7 processes strict quality control system and professional R&D department
2.100% pre-tested before leaving the factory
3.1:1 replacement for any defective caused by our factory
4.Specialized Ultra thin power bank factory with 6-years experience
5.Excellent customer service and technical support
6.Professional and Cooperative logistics company, best shipping service.
Introduction:
Professional Portable Power Bank Factory
Color: For customer option
Logo Print: According to customer needs(Transfer printing/Silk printing/Color printing/Laser printing etc.)
Test Certificate:CE,Rohs,FCC,SGS
Packing:gift box, metal case, carton box, customized packing as per travel charger
Stock samples:1 days
Making samples:1-3 days
Production day: Around 10 workdays
Loading port: Shenzhen,china
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Am I calculating this right? 25600mAh Power bank Capacity test

Hi,
I have recently bought a Li-Polymer power bank which has a rated capacity of 25600 mAh @ 3.7V or 94720mWh. Now, I have been testing this power bank using a 1A and 2A load. Here are the readings I got whilst charging and discharging the power bank.:
Here's the readings:
Charge: 24897mAh
Discharge: 16985mAh @ 2a discharge
Charge: 24814mAh
Discharge: 15020mAh @ 2a discharge
Charge: 24787mAh
Discharge= 16759 @ 1a discharge
Charge: 24750mAh
Discharge = Yet to do
Lets take example 1 from the list above:
Charge
24897 x 5 = 124485mWh
There was a conversion from 5V input to 3.7 output, with an efficiency of 80%
124485 x 0.8 = 99588mWh
So 99588mWh or 26915mAh @ 3.7V should be the power bank capacity
Discharge using 2A load
16985 x 5 = 84925mWh
84925 is the capacity after efficiency loss (20%) from the circuit. So power output before conversion and loss will be:
84925 x 1.2 = 101910mWh
101910 or 27543 @3.7V
So the power bank's capacity in the above example is around 27000mAh. Just wanted to make sure that my calculations were ok.
All readings are at 5V. The powerbank was charged at 2A and discharged at 2A or 1A USB resistor load.
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and this was used to record mAh

anyone?

[Review] Parkman E2 pluggable power bank for under 10$

Hey,
some days ago Parkman sent me one of their E2 powerbanks for review so here it is now.
Let me first clarify that I am neither paid by them nor related to them in any other way.
Let's start :highfive:
Content:
The powerbank ships in a small box with all information printed onto it. Also it comes with a micro USB cable to charge it. There's no wall charger included but charging it over USB is totally sufficient. Despite the cable and the powerbank there are some warranty cards and instructions in the box as well.
Powerbank itself
The big advantage of this powerbank is that it is really small and has a built in output plug
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It has 2200 mAH and I was able to charge my Blackview Alife P1 Pro smartphone (3000 mAH battery) to 64%. There are four LEDs on the powerbank which indicate how much juice is left - very handy! You can see them in the top of the image.
The only problem I had was that I could not really charge it in my pocket because the phone's USB slot is not centered but on the top left side. You can also see this in the image above. This makes the powerbank stand out a bit. On another phone I where the slot is centered it was completely fine though (see: http://imgur.com/qAWl96v.jpg) So definitely check the location of your USB slot before buying this powerbank
Conclusion:
Would I recommend this powerbank? The answer is "it depends". On the one hand it is really really handy and very portable. On the other hand 2200 mAH are nothing special nowadays. If you need to extend your phone's battery for one day go for it! If you want to go on a road trip over several days the capacity is definitely too low. I for myself use it every now and then when I am in town and my phone's battery is about to die.
Link: amzn.to/29Jnarx

What is the smallest charger we can buy?

Hello.
What is the smallest QC3.0 (or even better 4.0) charger in the market?
Most chargers are too big. And if you disassemble them you can see they are almost empty inside, they could make something more compact. (Though I understand there could be some thermal limitations).
Most chargers are like this one or larger (or with several USB ports).
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I would like to get an EU charger without the USB port, just the cable inserted on the charger, like the old ones but QC3.0.

Battery1inc World's Slimmest and Smallest.

Info about Slimmest charger
JS_Savior said:
Battery1inc World's Slimmest and Smallest.
Click to expand...
Click to collapse
Battery1inc World's Slimmest and Smallest 15W Dual USB Wall Charger Travel Ac Adapter Energy Star Level VI Standards (Patent and UL Certificate Version)
With 90 degree foldable AC Prong plug in(U.S. Plug),Dimensions 78.9mm*39.9mm*10mm Smart IC Technology , Fast Charging iOS iPhone , iPad, Android Smartphones and Tablets etc USB Mobile devices
Charge two devices simultaneously:Use your existing USB charging cables to charge most USB powered devices / Easy-to-see LED confirms whether USB charger is properly connected
Soft blue LED shows when charger is receiving power, efficiency 82%
Input:100-240V 400mA ; OutputC 5V 3.1A Max. or 15.5W ( Max. 3.1A,up to 2.4A per port)Smart IC technology auto-detects your device's input to charge at maximum speed
Sophisticated circuit design with OCP/OVP/SCP over-heated, over-current, over-charging protection. Charging will be automatically stop when battery is full.
Source-Amazon