Charging NiMH Battery With Constant Current Source

[civic3106]

Hi,

Need help here. I am charging my brand new LRP HiVolt Plus 1200mAH NiMH 5-cells battery with my Topward Lab Power Supply with the following setup:

- Constant current of 120mA (i.e. C/10)
- Charging Volt 9VDC
- Connected a volt-meter across batt
- Connected a amp-meter in series with the batt

After charging for 4 hours, the voltage across the batt show 5.65VDC and remain there for the next 10 hours. My feeling is this is not right. A 4-cells batt may looks ok with 5.65VDC but a 5-cells should gives about 7.0VDC or more.

I am not very sure but think one of the cell could be dead and shorted. May any kind soul here advise me. Thanks alot.

[X34]

Could be u cc charger not able to deliver the voltage needed at that resistance.

I am not very sure if cc charging is ok for nimh batt.

cheers

[civic3106]

From my understanding CC charge for NiCd and NiMH and CV charge for Lithium.

My Lab Power Supply is able to set the max voltage for CC charge.
Same apply to CV charge max current is settable.

[X34]

Check out this article Nimh charging

[civic3106]

Found the problem. According to the web site. NiMH is not suitable with slow charge i.e. 0.1C. After using fast charge i.e. 1C, battery voltage reach 7.10V which sound good. Has taken out the battery and will see whether the voltage hold after 1 day. Thanks for your help, really appreciate very much.