Is this right?

[punchy187]

If I had a battery charger that had a 5.0 volt 1000mA output and was charging a battery that was 3000mAh should it take a little less than 3 hours to fully charge the battery?

 

[Java_Az]

Sounds like you have just a AC adapter there. Not a charger. If it was a li ion charger it would be 4.2 volts. If the output was 1000mA it would take around 3 1/2 to 4 hours to charge a 3000 mAh battery. Reason being that once a li ion battery charger gets to around 3.6 to 3.8 volts it starts cutting back on the charge amps. the higher the battery voltage gets the lower the amount of amps the charger puts out. Around 4.1 volts most chargers are putting out less then 200 mA.

 

[punchy187]

I typed it wrong it is a Tenergy 2 Bay Charger with the Output DC 4.2Volts 1000mAx2 that I bought at the local batteries Plus store. Those supposed 4000mAh only took about an hour and I have yet to get them to work even though I can read voltage off of them. The BRC 3000 mAh took less than an hour and haven't tried them yet but I am guessing they are duds...lol. I do have an AC Adapter Model:USB-A that has a Input: DC 5 volt and an Output: DC 4.2 volt=420mA but I have never gotten a mod to charge off of it for some reason. I only use it for the ego-t I have bought from the local store that I use for a back-up. What is the Input: DC 5 volt referring to anyway? Is that what the charger takes in from the outlet?

 

[CraigHB]

There's two primary modes for Li-Ion chargers CCM and CVM. The charger runs in constant current mode all the way up until it hits the voltage limit of 4.2V. That's when it switches to constant voltage mode where current begins tapering off. For CCM, you can divide out the charge rate into the capacity to figure out how long that phase lasts. Once you get into CVM, it takes a half hour to an a hour for charging to complete. So, a 3000mAh cell with a 1A rate would run around 3 hours in CCM, then run for a half hour to an hour in CVM. The whole cycle for a fully discharged 3000mAh cell would take 3.5 to 4 hours using a 1A rate.

EEVblog #176 - Lithium Ion/Polymer Battery Charging Tutorial

 

[punchy187]

Thanks for that. Unless the CVM is critical to complete for the batteries health or life span it would save a lot of time just to skip that part and start using the batteries at that point since they have no memory effect or wouldn't it?

 

[CraigHB]

Yes, you can skip CVM since it only accounts for a small percentage of the overall charge capacity. If you took the time to view the rather long video, that's explained in some detail.

 

[Java_Az]

Li-Ion battery burnout - YouTube