Protection Circuit?

Joined
Aug 3, 2016
Messages
31
Likes
7
OK, so I bought a cheap 5 volt power bank designed for charging phones. Inside it was a 3.7 volt, 2200 mah lithium ion battery and a protection circuit that boosts the output to 5 volts. Can I hook up a different battery to the circuit? I have some 3.7 volt, 3200mah lipo batteries that I'd like to use instead...
 

BocuD

.
Joined
Jul 21, 2016
Messages
468
Likes
606
Location
The Netherlands
Portables
3
I'm not sure, but it seems like you should be able to. Never mess with batteries if you dont know what you're doing though. It can be very dangerous.
 

Stitches

2 and a Half Dollarydoos
Staff member
.
.
.
Joined
Feb 5, 2017
Messages
3,934
Likes
3,099
Location
Banana Bender Land, Australia
Portables
6
OK, so I bought a cheap 5 volt power bank designed for charging phones. Inside it was a 3.7 volt, 2200 mah lithium ion battery and a protection circuit that boosts the output to 5 volts. Can I hook up a different battery to the circuit? I have some 3.7 volt, 3200mah lipo batteries that I'd like to use instead...
You can hook up higher capacity cells without issue, yes. Just be aware that some cheap circuits will break if you connect too many cells in parallel. If the circuit comes from a bank designed to use one cell, it may not work with two or more. You may be better off buying one that uses multiple cells.
 
Joined
Aug 3, 2016
Messages
31
Likes
7
You can hook up higher capacity cells without issue, yes. Just be aware that some cheap circuits will break if you connect too many cells in parallel. If the circuit comes from a bank designed to use one cell, it may not work with two or more. You may be better off buying one that uses multiple cells.
So, if I use 1 3200 mah liPo battery it will be fine? Also, what would happen if I tried charging two in parallel? I am well aware of the dangers of incorrect battery usage but It would be great to have 6400 mah...
 

Stitches

2 and a Half Dollarydoos
Staff member
.
.
.
Joined
Feb 5, 2017
Messages
3,934
Likes
3,099
Location
Banana Bender Land, Australia
Portables
6
So, if I use 1 3200 mah liPo battery it will be fine? Also, what would happen if I tried charging two in parallel? I am well aware of the dangers of incorrect battery usage but It would be great to have 6400 mah...
No way to predict really. Unless someone else has tested that exact board before, the only way to find out is to try. I assume two should be safe, but any more than that I can't say. Is there any identifying info on the board itself that you could use to look up datasheets?
 

Stitches

2 and a Half Dollarydoos
Staff member
.
.
.
Joined
Feb 5, 2017
Messages
3,934
Likes
3,099
Location
Banana Bender Land, Australia
Portables
6
I have attempted to attach to attach different cells and multiple cells to battery boards in the past, and I certainly recommend against doing so. Every time I attached the new batteries, the board would die after some usage.

Another reason to not use these portable charger boards is the amount of mod work that needs to be done to them to integrate them into your portable design. Most of these boards have annoying "key" switches that you need to bypass or integrate in some manner, and you also need to remove the usb ports and rewire them to other locations in your portable. If the board has a flashlight led, you need to remove this as well, and the charge indicator leds must either be rewired or mounted along with the board in a particular manner in your portable. Additionally, many of these boards have an insufficient current output or multiple outputs that can't be tied together.

What you really need is a three board solution. 1st, an universal output board that can supply sufficient current (found HERE). With this board you can connect any number of batteries (in parallel) and the board will always work. 2nd, an universal charge-only board (found HERE). Like the first board, you can connect any number of batteries (in parallel) and the board will always work. 3rd, a low battery indication circuit (diagram found HERE). Is this three board solution more expensive? Will it take up more space in the portable? Yes, but you can use all the batteries you like, and wire up a proper charge-or-play or a proper charge-and-play circuit, while having sufficient current for just about any portable.
But it's still easier to just use a 7.4v circuit
 
Top