I thought I'd try one of these 24V 300w heater/demister units as a load bank for discharging 6s & 4s packs.
It worked well enough. It didn't use the full 300watts. But it was still faster than using my iCharger or my little 150watt discharger with the three 50w lamps.
And it was certainly cheap enough.
https://www.ebay.com.au/itm/24V-Heat...4AAOSwi0xaIhKi
So here are some figures.
I set up a wattmeter in line with the load & plugged an alarm module into the balance leads.
I jotted down a few values during the discharge.
6s 5000mah Revolectrix pack.
Start at 25.2v
Initial draw.
9A----24.8v----230watts
then quickly settled to.
7.9A----24v----190watts
Midway through discharge.
7.8A----23.5v----185watts.
End of discharge at 3.8v alarm. 49% capacity remaining
7.98A----22.83v----182watts.
Time----16 minutes
Resting capacity after a few minutes was 53%
4s 6000mah HRB pack.
Start at 16.8v
Initial draw.
8A----16.44v----140watts
Midway through the discharge.
8.5A----16.2v----136watts
End of discharge at 3.8V alarm. 50% capacity remaining.
7.5A----15.2v----114watts
Time----12 minutes.
Resting capacity after a few minutes was 54%
I think it is successful enough.
I quickly tried a 2s & a 3s pack. But the low voltage caused the 24v fan to spin too slowly. I think the heater bank resistor would burn out, or the plastic casing would melt.
I would have no worries about connecting two 3s packs in series for 6s or two 2s packs in series for 4s.
I have an extra alarm module for the second pack.
But 12V car versions are available for single 2s or 3s packs. They are only 150watts, but they might work well for the lower voltages.
Just thought I'd share.
Inside the unit showing the heater bank & the fan.
Attachment 155495
The setup.
Attachment 155496
A pic of the meter & alarm module during the discharge.
Attachment 155497