Constant Current Dummy Load

[billy_gr]

Hi,

My dive buddy asked me if i can come out with something cheap to do burn tests for the scooter batteries

Nimh
Rated at 41V
Nomimal 10Ah 400Wh

We have these options
1) A Programmable DC Electronic Load from BK Precision $$$$$
2) CBA IV - Computerized Battery Analyzer $$$
3) Build something $

Before going to the DIY with such a huge battery in terms of Wh, i really want to try something smaller to test my 18650

There is an old thread in cpf http://www.candlepowerforums.com/vb...e-a-constant-Watt-dummy-load-circuit-to-share but with no info

I have semi designed the schematic based on info i found on the net however there are some important questions to be answered before continuing...

Monitor it manually and decide when you should stop discharging or add a microcontroller

• In case we go we the second option what is the accuracy needed for the cutoff 3.7 volts or 3.72 volts ? (1 digit or 2 digits)
• Would you add an LCD for abjusting the settings or see below
• Is USB really needed or a plain old RS232 would be ok to do the setup ?
• Do we need timebased stamps ? Or after poweron X amount time is ok ?
• Do i miss something ? A flashlight with constant current driver should behave the same, right ?

Many thanks for the insights

I can share whatever is needed regarding sch/pcb

Bill