Hello,

I have a 300mah 4.8V Ni-CD battery back (made with 4 cells) from an old toy.
The charger provided with the toy is not working.
Is there a way I can charge this using IMAX B6?

Thanks

Yes, the B6 will charge Ni-CD batteries. You may have to make an adapter depending on the plug your battery has

(19-Mar-2019, 01:49 PM)RENOV8R Wrote: Yes, the B6 will charge Ni-CD batteries. You may have to make an adapter depending on the plug your battery has

So i just select the mode as nicd charge, set current as 0.3A and start charging.
It will stop when battery is full?

I attempted to charge using imax b6 by setting mode as nicd and current as 0.3A.
I saw the voltage on display going above 6.0V, I was not sure so I disconnected.
Is this normal? What would be the end voltage on a 4.8V pack when fully charged?

(19-Mar-2019, 03:07 PM)sim_tcr Wrote: I attempted to charge using imax b6 by setting mode as nicd and current as 0.3A.
I saw the voltage on display going above 6.0V, I was not sure so I disconnected.
Is this normal? What would be the end voltage on a 4.8V pack when fully charged?

A 6v charge is fine. For Ni-CD batteries you need to charge the cells with a higher voltage than the nominal voltage of each cell (which is 1.2v on a Ni-CD cell). So on a 4 cell 4.8v Ni-CD battery charging with a voltage of 6v, that is 0 3v per cell above nominal voltage.

The charger should stop charging when the voltage reaches 4.8v on a 4 cell Ni-CD battery (1.2v per cell).

Just make sure you've configured the charger for a 4 cell Ni-CD battery.

Voltage during charge on Ni-Cd battery should be between 1.2-1.45V / cell but I have read that you can charge with voltage high as 1.55V / cell but I can´t find anything that confirms that. Your charger should have a setting fixed for Ni-Cd? 6V on a 4 cell pack gives 1.5V / cell which seems to be correct.

And yes, your charger will stop when charging is complete.

(19-Mar-2019, 03:51 PM)SnowLeopardFPV Wrote: A 6v charge is fine. For Ni-CD batteries you need to charge the cells with a higher voltage than the nominal voltage of each cell (which is 1.2v on a Ni-CD cell). So on a 4 cell 4.8v Ni-CD battery charging with a voltage of 6v, that is 0 3v per cell above nominal voltage.

The charger should stop charging when the voltage reaches 4.8v on a 4 cell Ni-CD battery (1.2v per cell).

Just make sure you've configured the charger for a 4 cell Ni-CD battery.

My charger does not have any option to set number of cells for nicd. The only option available is charge current and sensitivty.
Also the nicd pack does not have any balance leads. No sure how charger can identify it as 4 cells.

(20-Mar-2019, 06:02 AM)sim_tcr Wrote: My charger does not have any option to set number of cells for nicd. The only option available is charge current and sensitivty.
Also the nicd pack does not have any balance leads. No sure how charger can identify it as 4 cells.

That sounds a bit odd. I've never tried charging Ni-CD batteries on my charger so I'll need to take a look at what options I get on mine.

Ni-CD cells are 1.2v so if your battery is specified with a nominal voltage of 4.8v then it must contain 4 cells.

Most Ni-CD packs (and Ni-MH packs for that matter) don't have balance charging capabilities. If one cell starts taking less charge than the others then the cell will just progressively deteriorate until the pack as a whole is deemed to be "dead" because it will no longer hold the overall required charge voltage.

I had a look at my charger (a SkyRC Q200) and it's exactly the same. There is only the ability to set the charge current for both Ni-CD and Ni-MH batteries with no ability to set cell number or voltage. I'm still not entirely sure how the charger knows the number of cells in order to apply the correct charge voltage, but looking in the manual and also at a few videos on YouTube, there seems to be some kind of intelligence built into these type of chargers that somehow knows what voltage to apply. People charging 4 cell Ni-CD packs were getting a charge voltage of just under 6V (example HERE), and others charging 6 cell Ni-CD packs were getting a charge voltage of over 8V (example HERE).

So I think the bottom line is that you don't need to worry about it. These automatic chargers have all the intelligence and safety features built in to keep you safe when charging, as long as you don't try to bypass those features or do something stupid.

(21-Mar-2019, 11:41 AM)SnowLeopardFPV Wrote: I had a look at my charger (a SkyRC Q200) and it's exactly the same. There is only the ability to set the charge current for both Ni-CD and Ni-MH batteries with no ability to set cell number or voltage. I'm still not entirely sure how the charger knows the number of cells in order to apply the correct charge voltage, but looking in the manual and also at a few videos on YouTube, there seems to be some kind of intelligence built into these type of chargers that somehow knows what voltage to apply. People charging 4 cell Ni-CD packs were getting a charge voltage of just under 6V (example HERE), and others charging 6 cell Ni-CD packs were getting a charge voltage of over 8V (example HERE).

So I think the bottom line is that you don't need to worry about it. These automatic chargers have all the intelligence and safety features built in to keep you safe when charging, as long as you don't try to bypass those features or do something stupid.

Thank you. So I just set my charging current as 0.3A (my pack is 300mah) and select nicd mode and just charge.

I tested and it worked fine.

That's good news  Thanks for confirming it's all working fine. If I ever need to use mine to charge Ni-CD or Ni-MH batteries I now know it will all be good without any worries.

If you edit your original opening post and change the tag against the title from "Help" to "Solved" that will show anyone else with the same question that this thread contains the solution/answer