4x18650 battery box question

So i charged it up with my mobile phone charger, LED gets green battery 4.19V. Good.
Also tried the other input with a normal Dc round plug3.4mm works also(inner pin is plus and outside should be minus).
Tried no voltage over 6V in.

I put it on my power supply and played a bit, under 3V it switches off…under voltage protection is built in. good
Pulls about 1.3A almost over the whole voltage range 4.2-3V from the battery, with a iPad plugged in.
I shortened one spring to put a protected Sanyo in, would go without but I wanted a perfect fit.

Will you link us to the 6x box you purchased? Now I have to have one.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=150946900822
It’s not available anymore, but you might find same one by other eBay or AliExpress sellers.

What happens if you put a protected cell in a charger that already has protection? The ebay page specifically says to use unprotected batteries. I measured the batteries after they were charged and it read 4.28v on my harbor freight multimeter, so the overcharge circuit must have worked.

What can happen? Nothing.
I am on the save side of life and my batteries are save too, when I use protected ones. Without there can happen anything.

I could charge a unprotected cell in mine to check if the charger has proper voltage switch off or if it was the protection of the battery.

should the charger be cutting off before 4.28v? is that overcharging the batteries?

Yes it should.
My 6 cell one stops charging at 4.2V, and in few hours, voltage drops to 4.17-4.19V, so it might have better charging circuit than 4x one.

I have not tested charging of unprotected cells yet but we all have to think of that a cheap dmm could do measure wrong too.
I’m just right now charging my phone

I ve been using mine to charge my iphone all week. Last night it started flashing and my iphone kept making the sound it makes when you first plug in your charger. Think it would mean its low on battery?

I just bought a similar power box with 18650 on parallel,
One question, is it safe to mix match cells as it is in parallel?as in using different cells or different starting voltage.
Sorry if this is a stupid question. :8)
Thanks guys

Different cells is not a problem, but it is best to keep them fairly close in staring voltage (Say 0.1 volt).

Thanks a lot for the response HKJ

How safe is usingunprotected cells on one of these?

Depends on the box, the one I have reviewed is safe with unprotected cells.

Mine seems to be different.
battery box

Feature:
Output voltage: 5V
Output current: 0-2.5A (MAX Dual outputs total 3A)
Charge voltage: DC 5V,1A (recommended more than 1A ).the center PIN of Charging port is +. Battery protection: full auto stop, protection against overcharge, the battery voltage is below 2.9V start protection, turn off the output, you can perfect or protect the lithium polymer battery 18650! Charging time: 4pcs 18650 would take about 15 hours
Box size: 105 x 82 x 23mm
You can use 1 to 4 battery. Use four 18650 2600MAH battery, Capacity up to 10000MAH.
Please use the 18650 battery without protection. because this power box Circuit built-in protection. otherwise would burn the power box.

Mine seems to be different.
battery box

Feature:
Output voltage: 5V
Output current: 0-2.5A (MAX Dual outputs total 3A)
Charge voltage: DC 5V,1A (recommended more than 1A ).the center PIN of Charging port is +. Battery protection: full auto stop, protection against overcharge, the battery voltage is below 2.9V start protection, turn off the output, you can perfect or protect the lithium polymer battery 18650! Charging time: 4pcs 18650 would take about 15 hours
Box size: 105 x 82 x 23mm
You can use 1 to 4 battery. Use four 18650 2600MAH battery, Capacity up to 10000MAH.
Please use the 18650 battery without protection. because this power box Circuit built-in protection. otherwise would burn the power box.

There are many different models on the market, I plan on testing a few more, but at the current time I cannot help you with that one, you must test it yourself.

Connect a meter to the battery while it is sitting in the box, if you have a min/max button select min and then discharge, until the box stops.

If the meter shows any voltage below the minimum of the battery, do not use it without protected batteries.

For 2900/3100/3400 the minimum voltage is 2.5 volt, other batteries can have a minimum voltage up to 3 volt.

Thanks hkj,
Will test it once it arrive.
Hopefully its a good one.
Thanks for all your effort testing batteries and chargers in the market, you helped guys like me.
:slight_smile:

Parallel will always “automatically” balance. You should use batteries that are close (a few .1’s of a V) but they will balance themselves. CC/CV will work just the same as it will look like a pack of the capacity of all the cells added together - for example, 4x2500mah’s in parallel will look and act like 1x10000mah pack.

This only works if you have equal cells, but the Chinese crap a lot of people use are going boom. Also these laptop pulls…?
You can see this with the cheap bicycle battery packs, sometimes they are Realflames.

Also could it happen that if 3 cells are empty the 4th has to handle all the power this is very inefficient. After use the cells with higher voltage charge the ones with lower voltage…and so on. There are a lot of effects which I don’t want.

But you are right, theoretical they balance themself, this is done in battery packs for ebikes or ecars all the time but only with brand cells of the same build.

And as the most batteries are stronger than we think it will probably nothing happen if you make everything wrong…but perhaps you will burn your house…

There is a flashlight product name!