5V Power Pack for "FREE"

[garage nut]

After close on 50 days a few packages arrived from China.

I have red about the recycling of laptop batteries and creating "FREE" Power Packs.

I managed during the 50 days to find one laptop battery that produced 6 18650 batteries. they did not specify their capacity other than it is SAMSUNG, ICR18650 -26A.

So I ordered one 3 cell 18650 battery holder - $0.94 including shipping
3 x TP4056 charging modules - $0.86 including shipping
1 x 12v DC to 5V DC Module - $0.87 including shipping
So all and all and all $2.66 almost for "FREE" ....if it works.

That is About R40 in SA currency and a complete 3 cell battery pack is about R250 or about the price of a case of beers.



So glad to report that it works fine. You individually charge every battery on its own. Apparently a good thing as batteries in a pack like this never discharges/discharges at the same rate. There is a RED LED to indicate charging and a BLUE one to indicate fully charged. I have found an improved module that has a charge protection chip included. It still uses the TP4056 chip. I have ordered some of these as I would feel more safe knowing I can not overcharge the batteries.



Not pretty, just threw it together to see if it works. And it works great. It took those batteries from none higher that 0.5Volt to their full 4.2V The first charge took almost a day, But now I use this all over and a recharge takes only about an hour.

I fortunately ordered one extra TP4056 and I have wired this one up to charge the other 3 cells while using this pack and then when it is run down I just change them around.

Other drawback is it does not auto power off, So the RED LED on the 12v to 5V modules is illuminated the whole time while the batteries are fitted. So if not in use I remove them. Nice thing this module is rated at 3W. so this bank delivers a good punch. Shop bought units max out at 2.1W.

[editor@glue-it.com]

Hi All, thought it might be useful to put together a very high level page listing the points to consider in battery pack design:

safety, usable energy capacity, system operating voltage range, power capability, charge and discharge, time dependent power capability, lifetime, charge time, ruggedness, temperature environments, weight and / or volume, cost

[hemmjo]

Very nice Nut!! I would venture to say that MOST discarded Li-Ion battery packs only have one bad cell. Some that are discarded have all good cells it is just that one has been discharged too low. When that happens the "smart" charger cannot get a reading on the battery pack so it refuses to charges it.