Charging batteries with a power supply

Joshk · 2019-07-19T15:51:53.000Z

I started wondering how different chemistries are charged and if using a CC/CV power supply to charge them all is a good idea.

So for a li-ion 18650:
1- voltage = 4.1v
2- max current = 1.5A
3- connect battery
4- wait until current falls below 0.1A

Thoughts?

Couchmaster · 2019-07-19T16:07:24.000Z

Vague memory is Dave Jones did a video of that on Eevblog……back in time someplace.

HKJ · 2019-07-19T16:08:34.000Z

I use a power supply for charging in all my battery test, but it is computer controlled. This means I can simulate charging algorithms correctly.
For CC/CV it works nicely without computer control, as long as you disconnect when the current is low.
For -dv/dt or NiMH/NiCD it do not really work.

Why do you use 4.1V, do you want to get longer lifetime from your batteries?

Joshk · 2019-07-19T16:13:06.000Z

Can you explain charging algorithms a bit? How do the algorithms differ from the setup I described?

Yea longer life.

HKJ · 2019-07-19T16:16:32.000Z

Joshk:

Can you explain charging algorithms a bit? How do the algorithms differ from the setup I described?

Yea longer life.

A power supply with current limit will do a fairly good CC/CV, except you manually have to terminate it.

-dv/dt looks for a slight drop in voltage (a few mV) to terminate, this is not possible with a normal power supply

Joshk · 2019-07-19T16:23:31.000Z

Is there any harm in not terminating it? It seems overcharging would be impossible with the 4.1v limit.
And is dv/dt just relevant to NiMH?

HKJ · 2019-07-19T16:27:32.000Z

Joshk:

Is there any harm in not terminating it? It seems overcharging would be impossible with the 4.1v limit.

Yes, more wear on the battery. A few hours extra charge time is not a problem, days is a minor problems, months will add significantly extra wear.

Joshk:

And is dv/dt just relevant to NiMH?

NiMH and NiCd.
Most of my battery reviews contains a charge curve where you can see how I charged the battery.

Joshk · 2019-07-19T16:36:17.000Z

I checked out your site. Wow, good job!
I have a related question, I tried recharging some Energizer alkaline AA batteries a few years back, and some recharged great, and some didn’t recharge at all. Do you have any experience with this?

HKJ · 2019-07-19T16:44:55.000Z

Joshk:

I checked out your site. Wow, good job!
I have a related question, I tried recharging some Energizer alkaline AA batteries a few years back, and some recharged great, and some didn’t recharge at all. Do you have any experience with this?

No, but rechargeable alkaline is constructed different than standard alkaline.

Joshk · 2019-07-19T16:46:50.000Z

Yep, I know, I just wanted to see if they would recharge or not

Thanks for all the info!

moderator007 · 2019-07-19T21:00:44.000Z

I use the DPS5020 power supply to charge li-ions on a regular basis but I never leave it unattended or for very long after the charging current has become low.
I think Texas_Ace uses his for this purpose alot too. I have never had a problem charging, checks out to be pretty accurate and follows the proper CV/CC algorithm as HKJ pointed out. Works great for me.