New consulting relationship with GreenTecAuto begins
What actually goes wrong with the batteries????
A look at todays Hybrid and EV battery packs
Battery packs exposed
2006 and up civic packs
Lead acid battery failure examined
Testing the sticks at the cell level
MaxIMA stick full discharge
Bumblebee battery replacements for the stock subpacks
Inside the cells
Seprating the cells for reuse
How it is wired
PTC strips exposed
The PTC thermistors
Battery current sensor
Inside the 100A semiconductor battery pack fuse
Did it again for the last time
A bad Prius subpack explored and fixed????
Rebalancing the Insight battery?
Insight battery
Insight Battery switching/current monitoring
The battery controller
Prius battery pack
State Of Charge (SOC) determination with NIMH batteries
Battery pack monitoring
What happens to a Prius subpack when you overcharge it?
Keeping Warm In New England
Plugging into the SUN
Making a small solar concentrator
Building MIMA and the plug in adapters
Converting a telephone truck to electric
DIY dual pulse Capacitor Discharge Spotwelder
Chevy Bolt EV joins the family
Getting in shape while making electricity
Replacing gasoline with solar electric lawn equipment
What is Genesis One?
How to stop the aging process DIY
MIMA Install Day 2005 a Big Success!
Building a hybrid car grid charger
Tapping into the Wind
Expanding MIMA with the Distribution board ( users projects )

State Of Charge (SOC) determination with NIMH batteries

State Of Charge (SOC) determination  with NIMH batteries
IMA system SOC determination

The terminal voltage of a lead acid or Lithium battery can be used to determine the SOC, since it drops as the battery is discharged.
The discharge voltage of a NIMH pack is very flat, compared with other batteries, so the best way to determine the SOC is to measure the current into and out of the pack. The minimum SOC where one of the subpacks reaches the drop out area of the curve is used to start a forced recharge called a recalibration. The full SOC condition can de measured by watching for the voltage change at the full charge point, as well as the rapid rise in temperature when at that point.