Category | Design

Design

Written by chivey on July 5, 2026 Tags: Design

Project design

Research

Some related projects from the internet: Reference designs
Modeling: EV calc model

2008 Original goal

My daily commute is 8 miles one way, reaching a max speed of 55mph (usually only for 3 miles and only in the morning going to work – never in the evening – ATL traffic!)

Minimum system performance is a range of = 16 miles (round trip to work) reaching a top speed of 55mph for about 30-40% of time. Daily recharge option.

Ideally would like to be able to make a round trip to the airport. ATL international is 40 miles door to door from my house, most of the way is freeway at 55-65mph. The ideal would be able to make the trip there and back (80 mile round trip), but an option could be talk to some of the off site parking lot folks and see if a recharge option could be found. Would definitely be good promotional opportunities here…

Target design range = 80 miles spending 70%-80% between 55-65 mph.

This design would require significant power and capacity to achieve and the question about the aerodynamics of a VW bus becomes serious consideration.

An intermediate design (using recharging at airport parking lot) would reduce the design to 40 mile range spending 70-80% at 55-65 mph – much easy to achieve and similar to existing designs and builds found on the internet.

Starting the design considerations with this in mind will plan on specify components with good ranges above our initial application to allow growth in to hopefully the ideal design if not achievable in the first phase.

2012 Updates

Design changed driven by failing Lead Batteries (old) and exploded controller (Logisystems apparently are not as good as they claim)

2016 New England design

My daily commute is now 20 miles, with easy recharging options at the office. However strongly prefer to charge at home (cheaper) – existing design should cover this.

2026 Lithium refresh

After several years of on/off work, deciding to re-invest in solving the poor lithium performance. Aim is to replace battery pack as cleanly as possible (and BMS) targeting 80-90 mile range.

Design revisions

V1.0 DRAFT

Based on existing projects

MotorNet Gain Wrap 9
ControllerCurtis 1231C
BatteriesCostco 115Ah/12v x 12
ChargerZivan NG 3 110/220 charger
ClutchYes

V1.1 DRAFT

Refinements after discussion with David

MotorNet Gain Wrap 9
ControllerLogisystems 144-156v 750A
BatteriesCostco 115Ah/12v x 12
ChargerManzanita Micro PCF 20
L30-6 connector
ClutchYes
Primary circuitFuse
Contactor
Manual disconnect (with driver operated cable)
Secondary circuitFuse
Key-switch
Inertia kill switch
Charger interlock

V1.2 – Implemented

Based on the battery selection, here is first on road implementation

MotorNet Gain Wrap 9
ControllerLogisystems 144-156v 750A
BatteriesMax Rate AGM 12 x 12v
ChargerManzanita Micro PCF 20
L30-6 connector
ClutchYes
Primary circuitFuse
Circuit breaker
Contacter (x2)
Manual disconnect
Secondary protection circuitFuse
Key-switch,
Charger interlock
(Brake interlock)
Secondary warning systemMotor overheat
Charger interlock
System ready
Brush wear warning

V2.0 – Project design (Upgrade to Lithium & replaced L30-6)

MotorNet Gain Wrap 9
ControllerLogisystems 144-156v 750A
BatteriesGBS Lithium 48 x 3.3v
BMS: Lithimate Lite
ChargerManzanita Micro PCF 30
J1772 connector
ClutchYes
Primary circuitFuse
Circuit breaker
Contacter (x2)
Manual disconnect
Secondary protection circuitFuse
Key-switch
Charger interlock
(Brake interlock)
Secondary warning systemMotor overheat
Charger interlock
System ready
Brush wear warning

V2.1 – Project design (Replace controller)

MotorNet Gain Wrap 9
ControllerSoliton Jr
BatteriesGBS Lithium 48 x 3.3v
BMS: Lithimate Lite
ChargerManzanita Micro PCF 30
J1772 connector
ClutchYes
Primary circuitFuse
Circuit breaker
Contacter (x2)
Manual disconnect
Secondary protection circuitFuse
Key-switch
Charger interlock
(Brake interlock)
Secondary warning systemMotor overheat
Charger interlock
System ready
Brush wear warning

EV calc model

Written by chivey on  Tags: Design

EV calc (http://www.evconvert.com/tools/evcalc/) model of the StealthBus.

Summary

ConfigurationRange @ 30 mphRange @ 60 mphTop speed (Limit)
Lead pack / Logisystems43.625.7
GBS pack / Solition Jr48.529.0
Tesla pack / Solition Jr96.756.074 (Battery Voltage)

Vehicle (1973 Volkswagen Bus)

Drag Coeff0.38
Frontal Area27
Initial Curb Wt2900
Drive efficiency0.91
1st gear ratio17.366
2nd gear ratio9.40963
3rd gear ratio5.76277
4th gear ratio4.06273
Final ratio4.57

From various VW specifications

Motor (Net Gain – Warp 9)

Voltage192
Weight135
Horse Power35
Maximum RPM5000
Motor a46239
Motor b0.4564
Motor c2436
Motor d303
Motor k0.0069
Motor n1.5845

Standard model from EV Calc tool.

Battery (GBS)

Voltage12.8
Weight
Puekerts Exp100
Puekerts Cap1.05
Resistance0.006

Battery (Tesla 5.3kWh)

Voltage22.8
Weight55
Puekerts Exp232
Puekerts Cap1.05
Resistance0.006

System

Voltage144
# Batt Strings1
% DOD100
Charger Weight20
lbs Removed600
Misc Added lbs500
Incline1
Wind0
Tire Section195
Tire Aspect50
Tire Rim15
Rolling Resistance0.015
Brake/Steer Resistance0.003
Kwh Rate0.09
Commute Miles20

Battery Pack (C&D Tech Max Rate AGM 138Ah)

Voltage12.8
Weight100
Puekerts Exp1.082
Puekerts Cap163.244
Resistance0.0023

From C&D datasheet, converted to Puekerts using EV calc tools.

Controller (Logisystems AFX 156)

min voltage120
max voltage156
max current750
weight20
efficiency95

From Logisystems datasheet

Reference designs

Written by chivey on  Tags: Design
ModelMotorControllerBatteriesVoltsChargerMPHRange
1957 S/CabADC 9”Curtis 122120 x 6v120n/s6560
http://www.evalbum.com/115
1966 SplitADC FB 1 4001ACurtis 1231C10 x 12v AGM120PCF 50/757049
http://www.evalbum.com/384
1967 SundialWarp 9Cafe Electricn/sn/sn/sn/sn/s
http://www.evalbum.com/1755
1970 BusNet Gain Warp 9Kelly 144V/650A18 x 8v flooded144Zivan NG 36550
http://www.evalbum.com/1581
1971 BusADC 9”Curtis 122120 x 6v120n/sn/sn/s
1971 BusADC FB 1 4001ACurtis 1231C24 x 6v flooded144PFC 306045
http://www.evalbum.com/2100
1972 BusADC FB 1 4001Curtis 1231C10 x 12v flooded120Lester 110/2206540
http://www.evalbum.com/1755
1973 BusCustom 9 inchCurtis 1231C24 x 6v flooded144Zivan NG 35550
http://www.evalbum.com/1804
1973 BusADC FB 1 4001Curtis 1231C20 x 6v flooded120Dual KTA6540
http://www.evalbum.com/159
1977 BusADC FB 1 4001ACurtis12 x 12v flooded1442 x chargers6530
http://www.evalbum.com/1915
1978 BusNet Gain Warp 9Curtis 123124 x 6v flooded144PFC 15006060
http://www.evalbum.com/2843
1979 BusADC 9”Kelly20 x 6v flooded12010 x 12v chargers5050
http://www.evalbum.com/2075