Waste-time during charging (Bantam Chargers)

[KiZ]

My Bantam charger's default NiMH charge mode (it calls it "normal" mode) charges for 90 seconds at a time with 6 second pauses. It claims this increases the charging efficiency.

Can anyone explain why? Does letting the battery chemistry have a break every so often help it charge more effectively?

[BrianG]

Not familiar with Bantam chargers, but generally, it's just measuring the voltage during charge and at rest. If the difference is too great, the charger knows the charge current is too high and will reduce it. If the difference is really low, it can boost the charge current a bit. This is how the charger knows what the safe charge rate should be. There is still the delta-peak (or thermal peak) shutoff.

[KiZ]

Thanks for the reply.

There is in fact a separate mode that facilitates automatic current detection, but it is not part of the same mode.

The manual seems to give the impression these pauses are for performance/efficiency reasons, not for taking measurements (you can also set a mode that does not pause, but you can still enable peak detection and auto-current).

Normal: The charger will work with the parameters which were set at the screen. The feeding current will be at zero every 90 seconds to have 6 seconds of waste-time for higher charging efficiency.

And the auto-current mode is detailed in a separate section. Curious.

[_paralyzed_]

Originally Posted by KiZ

Thanks for the reply.

There is in fact a separate mode that facilitates automatic current detection, but it is not part of the same mode.

The manual seems to give the impression these pauses are for performance/efficiency reasons, not for taking measurements (you can also set a mode that does not pause, but you can still enable peak detection and auto-current).



And the auto-current mode is detailed in a separate section. Curious.

They had to explain the pauses to the user somehow. It was just more colorful to say it increases efficency.

[BrianG]

Maybe it's just a safety feature then that makes sure the difference between charge and float voltages aren't too high. Kinda like if you were to charge a AA NiMH at 5A. The voltage would increase to over 1.7v, but the resting voltage might be 1.2v. This 0.5v difference would be a red flag to the charger that it was set too high and set off an alarm or auto-reduce the charge current.

[KiZ]

Yeah I guess it could be. Who knows what these funny translated chinese instructions really mean anyway :)

[hoober]

Some chargers (not on auto-setting) do an open voltage check and if it drops 3 times in a row will disable the "peak delay at start" to re-engage the normal peak detection. Others may do the open voltage check and use another method to terminate.