2002 E825 GE Sentry Regenerative Braking question

A switch that will turn on motor brake. (plug brake)
Sound effects, better yet?
The only jake brake horn I can find is $100.

Hmmm.

For programming T1 and T2 controllers I prefer an LX Handset. Usually available from ebay or inwo. If you want a spread sheet with factory settings for T! and T2 (they are different.) Email me…

You are different from most flat land owners. This is the first feature most of us disable. I guess if your in the hills you might be comfortable with it.

It can be adjusted from mild to throw you thru the windshield.

@TJelecD I’m near Grass Valley. A bit of a drive, especially with your car in tow. I wouldn’t mind loaning mine out if I had an assurance of getting it back. I still play with it a lot and would not want to lose it.

@Inwo I like where you’re going. I hadn’t thought of using Turf mode because I’ve programmed it for my family to use with limited speed. Might be able to add the Jake and get both. I am planning to build a custom display module using Arduino this fall that will track all the key data I want. I had envisioned adding a switch on there and doing something like you have done with MM as a basis for the regen selection. I like the more simple approach you are moving towards.
For the sound, my future includes the installation of a Bluetooth amp for my stereo. I don’t see any use for a head unit and having to find a place to mount it. Perhaps I could add a Jake brake audio clip to play every time I hit the button. LOL

Doug is going ahead with the 24s Volt upgrade.
Someone needs to start a thread to share experiences, and keep smoke to a minimum.
The part that always gets damaged is bms. There is only one safe way to connect it, and I don’t seem to do a good job explaining it. :frowning:

The T1 and T2 don’t seem to run over 95v, even with spoof.
Older carts need suspension work.
Even a prewired harness needs to be tested before plugging into bms. (each pin)
Have bms off.
Plug in B- section first.
Isolate bms chassis from “floating” frame.
Extending lcd cable needs shielded wire and away from power cables.
First and last pins of bms plugs are duplicates.
Batteries are in series. One “low side” B-, and one “high side”. B+ (or two of each)
Harness plugs are not keyed.

Anything to add?
Most users don’t wish to share their smoke stories.
C’mon jump in, the waters fine. :slight_smile:

I’ll start a thread for my 24s Volt battery upgrade.

Hopefully I won’t have any smoke stories, but if I do, I won’t have any problem sharing them. No shame here.

I plan on trying to reprogram my T1 for more aggressive regenerative braking after I finish the lithium upgrade… Don’t want to mess with too many things at once.

Here’s my Lithium upgrade thread: Another Chevy Volt Lithium thread

Low side vs high side wasn’t clear when I was doing my project and I’m a EE. It just didn’t register. I had to really stare at the batteries and then the schematic before I hooked it up. Now, it is totally obvious but not when you first look at it.
What it means is there are 2 battery packs that are ~48V each. If you start at the first cell of the battery pack connected to car B-, the cell voltages increment by ~4V with each cell as you work toward the B+ connection. The first pack will have cells relative to ground from 4V to 48V. The second pack goes 52V to 96V relative to ground or B- on the car (remember that the car does not use a chassis ground like a normal car). The Pack that reads the lower 48V is the low side. See if the pic helps.
Battery%20Pack

If using 4 packs for ~100AH, it should be wired similar to below:24S2P%20Battery

For what it’s worth, I like to see the neutrals tied together. It helps take the load from the small balance leads. IMO

I’ve also heard from those advocating “inverse parallel” connection. @grantwest, I think it’s a plumbing term.
What I mean, is connecting B+ to the top battery.
I can’t see it making much difference, but it seems correct intuitively.

In practice, my car looks more like this under the seat but I thought that would be more confusing than helpful. LOL

Regen . I run regen all the way up , love it . From the factory it is set pretty low . i set mine to max and have it come on faster when i let of the accelerator pedal . Max regen is what a Tesla does , its sometimes refereed to one foot driving . This is really nice when : your cart goes much faster then stock , you live in a hilly area , you have front drum brakes .

so your racing along and need to slow down , let off the pedal and the cart immediately starts slowing fairly hard . If you dont want to slow that fast you feather the accel pedal. so there isn’t really a need to turn it off or on . And you are putting all that motion energy back in your pack instead of wasting it as heat (braking).

I like that approach and will try it. I don’t like how when I lift off the pedal going downhill the regen slows me more than I want to slow. From what your saying, I should be able to give it just a bit of throttle and get my target speed. I’ve always assumed that any pedal at all and I’m applying power which on my hills will have me speeding.
I’m going to play with those settings and see if I going the opposite direction of what I’ve done works better.
I love having the lithium because it can accept most of the current from regen. With lead, they can’t take the charge that fast so its mostly lost anyway.

i think there is a miss conception that is you apply a little throttle during regen that you are now using power . what it is actually doing is adjusting regen . i would run some tests and post results but the highest elevation in my city is … wait for it … wait for it … 3 feet ! seriously 3 feet . Not a whole lot of time to do down hill regen testing . Also you can reduce your plug braking with high regen . Plug braking is BAD .

What two settings are you changing to increase regen? I am trying to get mine to 1 pedal driving Tesla/Power Wheel style

4 settings below affect Regen. I focus on Armature current because its the higher current function. I don’t know what the ratio of that to Field should be so some of the smart guys might be able to clarify

FUNCTION 9 REGEN ARMATURE CURRENT LIMIT
(Push 9)
This function allows for the adjustment of the maximum
armature current limit during regenerative braking.
Range 32 to 240 amps
Set 1 to 255
Resolution 0.8157 amps per set unit
Example Setting of 221 = (221x0.8157) +32
= 212 amps
FUNCTION 10 REGEN FIELD CURRENT LIMIT
( Push 10 )
This function allows for the adjustment of the maximum
field current limit during regenerative braking.
Range 0 to 30 amps
Set 51 to 255
Resolution 0.147 amps per set unit
Example Setting of 180 = (180-51)x0.147
= 19 amps
CAUTION: Do not set this function to a value less than 51.
Important Note: The function is used to optimize motor and
control performance and this setting will be determined by
GE and OEM engineers at the time of vehicle development.
This setting must not be changed by field personnel without
the permission of the OEM.
FUNCTION 19 FIELD CURRENT RAMP RATE DURING
REGEN/PLUGGING
( Push CONT 4 )
This function adjusts the rate at which field current ramps
to full value during regenerative or plug braking when a
direction change is made.
Range 0 to 0.255 seconds
Setting 0 to 255
Resolution 0.001 seconds per set unit
Example: Setting of 12 = 0.012 seconds
FUNCTION 21 ARMATURE CURRENT RAMP DURING
REGEN
(Push CONT 6)
This function adjusts the rate at which armature current
ramps .8 amps steps to full value during regenerative
braking when a direction change is made.
Range .001 to 0.255 seconds
Setting 0 to 255
Resolution 0.8 seconds per set unit
Example: Setting of 12 = 0.012 seconds
Important Note: The function is used to optimize motor and
control performance and this setting will be determined by
GE and OEM engineers at the time of vehicle development.
This setting must not be changed by field personnel without
the permission of the OEM.

leave all of those alone . change #19 and #20 to 1 . also drop function #5 by 5 points

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@LithiumGods - I’m not sure I’m tracking you on this. Setting 20 is MPH overspeed on my T1. If I set this to 1 I will only be able to go 1 MPH. I’ve been playing with the settings but can’t get the desired effect yet. I want to eliminate Plug Current to avoid heat build up in the motor, but I think that’s all I’m getting because my SOI is always at 100% and so my regen is not kicking in. What value to you set value 14 Internal Resistance Compensation to get the SOI to work properly with your lithium?

forgot your on a t1 , i was referring to t4 settings . on the road and dont have a t1 manual with me to review .

back home next week

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I have the T4 manual as well. I’ll see if I can cross reference and make sense of it. Thanks!

Mr Vern, any luck cross referencing those specifically named T4 regen settings to the T1 electrical engineer settings?

Thanks

M@