someone suggested to check for the internal resistance.
i used to check for the internal but i can't figure out whether it is good or bad battery.
may be the method i used is wrong.

You can test for the capacity. Old battery will degrade resulting in lower capacity.

i have this and i think no.

first is the led indicator. there are only 3 leds. when charging phone, it will blinking from one to another, like flowing. but we don't know how much charge inside this powerbank. it doesn't show the level of the remaining capacity except u disconnect it from charging your phone. 3 leds doesn't enough to accurately show the capacity.

second is the charging voltage. inside there are regulator and ICs to control the charging limit. but it is fixed to 4.2V only. that means some other battery such as 3400mAh can't charge fully, which required 4.35V to charge fully.

and i think the efficiency is not good also. my 2800mAh battery perform less than expected. 18650s can get from taobao. some battery charging voltage limit are 4.2V and some are 4.35V.

My pineng unit also can't do this. It has higher priority to charge the phone than A/C charge your powerbank.

I don't think ultrafire have 5000mAh capacity.

normal price may be varies depend on your supplier. RM120 -150 is normal.
If seller take huge quantity, they can sell it at lower price.

How much you pay is how much you get.
so if you buy a cheap chapalang brand then you can expect it won't last long,
may have a risk of explosion too.

Now i don't have much time to do the test. Because my test required long time and manually calculate for the result. you may try to count how many times it can charge the phone.

Hi,
It needs about 12 hours to fully charge the powerbank, depending on the charging current.
There are no serial number on the powerbank.

sure ?
Because the seller told me 2800mAh and 3400mAh required 4.35V to fully charge it.
They have custom made charge to charge the battery until 4.35V.
They had tested and sold to customers.
I will personally test it if i have the chance to grab a 4.35V charger.

I think what you want to show is this right?

you done the test yourself?

nice equipment you have. Do you measure internal resistance before parallel the 18650 batteries ?

i wish i can replace this battery.



old battery under testing, used for 4 years already, can survive for half hour without ac power.

one thing special about laptop battery is the eeprom.
it will remember the percentage of battery. if i have fully charged it and discharge the battery bypass the circuit, it will resulting the battery cannot be charge through the circuit. laptop will show 100% fully charged.

i guess what should i do is before i dissasemble the battery, i fully charged it. new battery also fully charged. then assemble ot. should be ok.

may be the efficiency is not that good enough or it is using the recycled battery that have lower capacity.

The S4 cable i think is data cable. Please use pineng original cable as it is charging cable. Charging current will not be same.

yes. the AC charger have data pin shorted, so the phone can recognize it as AC power source.
But pineng powerbank don't have data pin shorted. The pineng cable is data shorted, so it is a charging cable.
you can try connect pineng cable with computer, see whether your computer can recognize your S4 or not.

i no longer selling powerbank already.
You can get it from other seller.

may be you can try ask from www.pineng.my