Will this charge my li ions - Page 1
Forum section: electronics / beginners

author: Grayfox
author_rank: Regular Contributor
timestamp: November 24, 2015, 08:06:37 am
content: I am making a lightbox using LED strips with 3 18650 cells that I have lying around.The cells will be arranged in series.So will this PCB board from ebay charge them correctly and would I use a 12v PSU which is under the total voltage for the combined voltage from the batteries or would i need to use a 4.2v PSUhttp://www.ebay.com.au/itm/4A-8A-PCB-BMS-Protection-Board-for-3-Packs-3-7V-Li-ion-18650-Battery-Cell-/281842115060?hash=item419f1961f4:g:u9UAAOSwstxVNc6zI understand how to wire it up to the batteries.

author: Srbel
author_rank: Frequent Contributor
timestamp: November 24, 2015, 09:35:49 am
content: That is a protection for making a battery pack, not a charger.If you have an adjustable voltage and current power supply, you can charge them manually. First set the PSU to constant current mode and set the current limit to 1A (for example), and measure the voltage of a cell. As soon as it reaches 4,2V (and that is 4,200V and not higher) you stop charging. Then switch it to constant voltage mode, and set voltage to 4,2V. Now you have to measure the current. When current drops to about 10% (or 5%) of nominal 1A (so 100mA or 50mA), then you stop charging.Or you can make a charger using Microchip charger IC.

author: Grayfox
author_rank: Regular Contributor
timestamp: November 24, 2015, 10:49:29 am
content: I have a foxnovo F4S charger but how would I go about charging 3 li-ions in series which would have a max voltage of 12.6v and minimum voltage of 9.6.Are their any protection boards that also provide balance charging like a TP4056?

author: Grayfox
author_rank: Regular Contributor
timestamp: November 24, 2015, 12:06:54 pm
content: Would I still charge them at 4.2v even if they are in series?I dont have a CC-CV based PSU, looking to see if ebay has anything.Could I use a laptop charging circuit?I got 8 NCR18650s out of my old asus and it did not have a balancing charger.The board had 3 wires, Black, Red and White.The Black was connected to the negative, red was positive and white was the temp sensor.I do not have this board no more.

author: Grayfox
author_rank: Regular Contributor
timestamp: November 24, 2015, 12:53:30 pm
content: So if the batteries dont have chips in them, using the circuit out of a 3cell laptop battery should charge them if 12volts is used.http://www.ebay.com.au/itm/3-cell-Battery-for-HP-Mini-210-1000-210-1100-590544-001-596239-001-/151418775812?hash=item2341432904:g:QtwAAOSwxH1UH5QnI do have an old spare 12v 1A PSU from an old modem that could work.Think I also have some sub amp ones too.

author: Grayfox
author_rank: Regular Contributor
timestamp: November 25, 2015, 11:20:00 am
content: Just found this.http://www.ebay.com.au/itm/Blue-12V-DC-Power-3000mAh-Super-Rechargeable-Battery-Pack-Adapter-Plug-/311164141028?hash=item4872d3fde4:g:tuIAAOSwzOxUXGwNComes with a +12v 500mA EU plug, by the looks of it it could either be a LiPo pack or 3 18650 cells.It looks like it will suit my needs.

author: mikerj
author_rank: Super Contributor
timestamp: November 25, 2015, 07:50:40 pm
content: Quote from: Grayfox on November 25, 2015, 11:20:00 amLooks perfect if your needs include "built in incendiary device"In all seriousness if you buy this, do not leave it charging unattended. Who knows what level of protection is or isn't provided within the pack, and you just know the charger won't meet any regulations on isolation.

author: Grayfox
author_rank: Regular Contributor
timestamp: November 25, 2015, 09:32:38 pm
content: Being an EU charger It wont work here(Australia).I have some 1A and should have a 500mA one that outputs 12v