Custom Battery Case Study for Mobile Jammer

A Story You Must Read If You Are not So Familar With Battery Design

Before you read the story, let’s  see the total amount for the first order.


yes, that’s 120,000 USD, worth reading right, let’s start the roll.

On May 5, 2014, Just around 2pm, Our Reception Got a call from Anan and he said he want 5000 pcs power bank but with special output, later he sent us email


Oh You see, he don’t know he want power banks or battery packs


we asked for the dimension requirement and battery input and output information



the problem now comes out, it’s 5V 12A, almost there is No PCB that carries that high current!


and what’s worse the capacity the customer calculation was also wrong. Totally a Mess.


Second problem, the price. there is huge gap between our price and the customer target price. he want 10USD and our bid 35, yes it’s 35USD

See our explanation below:

PS: we bought immediately one jammer from the market and know that 5V 6A is enough to Power it On.


the customer also send us one jammer to see if we can make a battery for it, and correctly.8a

but no success, we cannot get it because of the Chinese customs.


At this stage the customer is still not so trust on our batteries, so we bought case from the market and made a battery sample for him, see the pic on our invoice, very ugly isn’t it?

But it worked, and we are the only one that make it success on his device, see picture:

non working battery



the bargain started, the customer lifted their price to 15 dollars.


and we are negotiating on potential solutions, like cut the time or capacity

13a second round of negotiation, 25 dollars


see the bargain

later the customer send his Chinese agency to come and check our factory and had several bargains. and the deal finally comes.

this we started making second round of samples, using custom design casing(mold fee paid by customer)

second sample sent for approvement


battery packs

Data sheet(with demo sample)

data sheet

the deposit for the starting of the battery mass production


The Production starts:

production 2production

white box for the battery packs

white box

210 cartons battery packs

batterypack carton

Airway bill


The packing listbattery packinglist

battery packinglist 2


In general, our process for custom battery packs

battery design process

Design My Battery Pack