18650 chargering system - Computers & Internet

Does it look like these. The other alternative is to take the battery apart and get replacement 18650 batteries and connect them up.

https://usa.banggood.com/buy/tornado-tools-18v-replacement-battery.html

Charger and 2 batteries is $142.80.

The charger can be purchased by voltage output and the plug.

Or, buy this and get the battery and charger with a spare saw for $108. :>)

https://www.heartlandamerica.com/tornado-tools-gt38016-cordless-pole-saw.html

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Make sure that both batteries are the protected type
https://commonsensehome.com/18650-battery/

My Evatac flashlight rechargeable batteries not working .when connecting batteries to charger light flashes green red green red ect. What is the problem

Easy to find on Amazon, eBay, both batteries 18650 and charger.
Cheaper on Aliexpress but you have to wait a few weeks.

There are a number of websites on the internet which are offering information relating to 18650 battery. These are specially made for all those Men and women that are looking for quality advice relating to 18650 battery. To Learn More please see this site:http://www.seafishinghowto.com/fishing/articles/best-18650-batteries-and-chargers.html

Can get a 4 gang charger on eBay, ~ $20.
If they're wired in series, (nominal 37 volts) will need a DC power supply capable of 40-50 volts DC. Limit the charge current to 1-2 amps with a series resistor or a small 115 volt light bulb..

Yes. The first step is to open the battery and check the condition of the wiring for breaks, corrosion, etc. Also check the condition and voltage for the individual 18650 cells. Ryobi batteries are relatively easy to disassemble using available tools, see posting below.
https://www.ifixit.com/Guide/Cell+Re-balance+of+Ryobi+One%2B+18V+Li-ion+Battery+%28130501002%29/13286
Depending on the findings, some parts may need replacing. If you replace the 18650 cells, use new ones which are easily found on eBay.

Normally you should charge a battery for 14 hours on one tenth of the capacity. So if you have a charger capable of 400 mA/h you should leave it on the charger for 14 hours.

Why not buy one on ebay, it will be much more cost effective then buying the necessary test equipment etc so you can test what you built.