Difference between charging at 500ma and 1A?

I’m actually going to do some discharge testing on some cells that I left sitting out for a couple weeks.

The thing though is that they have been charged up at 500ma previously, since I am hoping to have consistent data that is representative across cells, must I always charge up my cells at 500ma? Or will it be perfectly fine if I charge up my cells at 1A going forwards?

Will cells be “more full” charged at 500ma as compared to 1A? (I am just wondering if what’s applicable to NiMh will apply to Li Ion too).

are you talking now nimh or liion

In case of lithium cells, you can charge it normally at 2C (C is the capacity of the battery, so if it is 2500mAh, you can charge it at 5A), but it depends on the manufacturer and cell specs, you should check that. 1C and 1/2C are safer, Normally I charge my LiIon cells at 1/3C and when it’s near full, the charger reduces the current to charge at 100%.
You should check that your LiIon battery doesn’t exceed 4.20V when charged, and if it’s with less voltage it is not fully charged.

its depend on battery type & capacity

If it Nimh, lower charging current increase charge termination accuracy.

for li-ion, high current affects only first stage of charging process (CC mode) once battery reach 4.2V, charging current drop.

lower charge current will fill battery almost full when it reach 4.2V

Normally every battery’s life extend if charged lower currents

Quite the opposite I’d say. After reading a lot of posts, 0.5-1C charging is recommended for better -dV termination.

Oh, actually I should reword my original concern :slight_smile:

Say I got a battery analyser discharging a cell at 1A. Will it make any difference in my test results if I charge it at 500ma or 1A?

PS: It’s a 18650 Li Ion.

i charge mine at maximum the turniguy accucell would go. 18650 NCR panasonics. i thinkt he charger auto drops current when its near full 4.17

About 500mA :wink:

Wow, didn’t know you could charge that fast. I now hate my tf100, charges at 450ma total, and with two cells, it takes around 10 hours from 3.5 volts.

It seems no one knows for sure. Why not do the test yourself. Be sure to rest the same battery before recharging/testing and let us know the results. =)

It is not the charge current that is interesting, but the charge termination current. I.e. at what current does the CC/CV charge stop, if that is the same current at both 0.5A and 1A, the discharge will be the same (Most hobby chargers uses 1/10 the charge rate as termination current, i.e. a different charge rate will affect the capacity).

You can see some curves with different charge rates in my SP2 review.