PB Downhill Regen

[madsend81]

So, an observation more than anything. I haven't researched through all the PB threads to see if anyone else has noticed this or not, but something I have noticed while using downhill grade and braking for regen.

My daily commute home takes me down a decent length hill. Usually the ICE kicks off as I start my descent and it's electric only all the way down. I've been able to monitor the EV Coach and maximize regen for braking as I control my speed down the hill. Near the bottom, I turn down my street and it appears I have maximized the regen of the battery. I'm ready to coast on my residential street and the ICE kicks on. If I give it a bit of the gas pedal, the ICE kicks off and goes electric again.

I surmise it's trying to use engine compression over the regen at that point to help control speed so the HV battery doesn't over charge. Once there is an opportunity to draw from the HV battery, it kicks off the ICE and runs electric from there.

I don't have the OBDlink MX+ or anything to read live diagnostics, so this just my engineering mind trying to figure out what's happening.

Anyone else experience this in the PB?

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[Snakebitten]

There is indeed a cap put on the SOC of the battery. With regen, the cap is raised above the ~63% SOC that normally exists for ICE-charging, but I think even the raised cap is barely above 70%?

 

[Oxford_Powerboost]

Yep! It’ll kick the engine on so you’re not burning out your brakes because once it’s out of room to charge the (small) battery, it’ll revert to friction brakes. In order to help save those, it kicks the engine back on for compression braking. I noticed for those times where you just tap the gas for a few seconds the engine will stay on but it won’t reintroduce fuel, it’ll still use the electric motor. If you maintain on the gas, it’ll turn the engine back off as you noticed

 

[Samson16]

A 7.2kW resistive load bank in the bed plugged into ProPower will keep your HVB from reaching 70% and it’s Regen all the way home!

 

[madsend81]

I'll just try turning up the seat heaters, rear window defrost and running the fan speed at 5 or higher next time!

 

[Samson16]

https://www.newair.com/products/g56

Mount that to a board, turn on full PPoB and plug it in. No need to bother with seat warmers, defrost, or fan speeds.

 

[Samson16]

I'm posting something I think would help keep regen braking active and not something I would actually employ to marginally extend the life of my brakes and possibly save a thimble full of gas.

Just thinking out loud about how the PB functions

 

[madsend81]

I'm posting something I think would help keep regen braking active and not something I would actually employ to marginally extend the life of my brakes and possibly save a thimble full of gas.

Just thinking out loud about how the PB functions

It's this type of "Red Green" thinking that eventually turns out useful solutions to life's problems. ?

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