Pulse Charging at low temperatures.

[Dzl]

I was looking at the datasheet for the CALB blue plastic ribbed cells (CALB SE180) and noticed that:

1. It's a damn nice datasheet. Very clear and a lot of detail!
2. It defines both a standard charging profile and a 'pulse charging' profile

This caught my eye, because I hadn't come across any discussion of this before, and more interestingly because CALB has a separate temperature and C-rate guidelines for pulse charging. The datasheet specifies that the batteries need rest time greater than or equal to the duration of the pulse between pulses.

What jumped out at me was that charging at a C-rate of 1C is permitted at temps down to -5 celsius so long as the pulse is no longer than 10 seconds at <70% SOC or 5 seconds at <80% SOC.

If 1C pulses are allowable down to -5*C under the above conditions, I wonder what the data would show at 0.2C or 0.1C.

It also got me thinking about ways pulse charging or discharging could be used (the stated purpose is regenerative braking) or might already be used.

Could a BMS or charger switch charging on/off at a 40% or 30% duty cycle to permit some charging in below 0*C temperatures?
Could a proprietary internal BMS like Battlerborn's BMS that allows below 0C charging already be doing this?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

[Off grid Colorado]

I believe the pulsed charging refers regeneration braking in electric vehicles.

 

[Dzl]

I believe the pulsed charging refers regeneration braking in electric vehicles.

Right, at least that's what I gathered from the datasheet. But from the batteries point of view, it shouldn't really matter what the source of the pulse is so long as the characteristics of the pulse charge are the same, right?

 

[Craig]

You may be on to something but I think it would be easier and cheaper to either use LTO cells or a heating pad. Never the less it is interesting info. Efficiency is another question.

 

[Dzl]

You may be on to something but I think it would be easier and cheaper to either use LTO cells or a heating pad. Never the less it is interesting info. Efficiency is another question.

Or the easiest/cheapest/efficient option for most use-cases, keep your cells somewhere that doesn't freeze--sometimes this isn't possible, but usually it is.

The pulse charging caught my interest mostly on a theoretical level.