Charging Issue with Fujitsu AA 2450mAh on SkyRC MC5000 – Stops at 400mAh

Batteries and Chargers Chargers
1

Hi everyone,

I’m having an issue with charging my Fujitsu AA 2450mAh batteries using the SkyRC MC5000 charger. With the following settings, the charging process completes, but it stops at 400mAh:

  • Target Voltage: 1.47V
  • Charge Current: 0.50A
  • DeltaV: Default (6mV)
  • Capacity Setting: 2000mAh (I’m aiming to charge to approximately 80% capacity)

Could someone please help me understand why the charging stops at 400mAh?

Also, could you recommend the correct settings for charging these batteries?

Thanks in advance!

2

Were they discharged before you started the process? 1.47V target voltage is probably also too low.

3

How old, how used are they? As batteries get older the internal resistance goes up and termination becomes more problematic. I think you can get an IR from that charger.

Why bother with 80%? They aren’t lithium and won’t benefit all that much from an 80% limit.
What happens if you just charge it full? Does it terminate prematurely?
Does that happen with ALL of those particular batteries? How about other batteries?
You need to determine if it’s a battery, charger, or setting problem.

4

The battery already discharged. When I connect to the charger it detected the IR as 150. After it charge to 400mah then the ir became 21. I have understanding the battery it save to keep between 20-80%? And I want to save the battery cycle. This does not apply to nimh battery? I am just testing on this battery. When I set current to 1.25A and target voltage to 1.67V ( the one with heart icon) while the rest of it remain the same the same battery able to charge until it stop at 1960mah.

5

No, different chemistry, different charging. Charge them completely full every time. Don’t charge them when they are already full or almost full.

As I said earlier, your voltage limit was set too low, so it stopped prematurely.

Usually I charge AA NiMH batteries with:

  • voltage limit: 1.65V
  • capacity limit: battery capacity + 10%
  • current: 0.5C (1A is usually close enough)
  • termination: 3mV -dV/dt
3 Thanks
6

Pretty much want @SammysHP wrote.
IR is appropriately tested on a fully charged cool cell.
NiMh is not lipo. 20-80% is not necessary. Due to the way they charge it is also pretty difficult to attain.
It is hard on them to run them DEAD (zero volts).
Full charge is not an issue.
LSD type should not be left on trickle charge after charging.
High capacity NiMh tend to have a shorter lifespan than ‘standard’ (~2000mAh).

3 Thanks