Measuring What Matters: Field Data on E-Rickshaw Chargers in Greater Dhaka Expose a Measurement-Basis Gap and Bound Potential Energy Savings
DOI:
https://doi.org/10.46610/IJREEPS.2026.v02i02.004Keywords:
Bangladesh, Charger losses, Field survey, Measurement basis, Power factor, Push–pull converter, Light electric vehicles, Techno-economic assessmentAbstract
Battery-powered auto-rickshaws are one of the fastest-growing vehicle segments in South Asian cities, yet studies of their charging load generally assume the efficiency of the chargers rather than measure it. This study reports a preliminary field survey of 55 battery–charger units (45 of the 48 V class and 10 of the 60 V class, all with iron-core chargers) in 10 garages in greater Dhaka, Bangladesh, in which voltage, current, temperature, and charging duration were recorded during normal garage operation. The recorded output-to-input power ratio averaged 31.3% (SD 0.9 percentage points; garage means 30.9–31.9%), with the 48 V and 60 V classes at 31.4% and 31.0%. This ratio cannot be read as a charger efficiency: output power was computed from the terminal voltage of a single battery rather than the four-battery pack, and input power was estimated as the product of voltage, current, and an assumed power factor of 0.82–0.97. On a pack basis, the same readings give 120–132% for all 55 units, which is physically impossible, so the survey identifies a measurement-basis problem in the recorded data rather than a charger efficiency problem. Because the true baseline efficiency is unknown, a bounding techno-economic model was run over baselines of 31.3–70%, three annual consumption baselines (two from cited inputs, one derived; 1.70–7.30 TWh/year on a 365-day basis), and retrofit efficiencies of 60–90%. Taking 31.3% at face value gives up to 47.8–65.2% lower grid draw, worth up to Tk 1,050–6,147 crore/year (about US$86–500 million at Tk 122.6/US$) at the BPDB-estimated average generation cost of Tk 12.91/kWh and up to 335–457 MW of avoided evening peak; the savings fall to 0–33% if the true baseline efficiency is 60%. A reduced-scale 15–30 V DC–DC push–pull stage measured about 92% ± 4 percentage points at 3–13.5 W, which is transformer-stage evidence only. Re-measurement of pack voltage and true input power over whole charging sessions, and rated-power testing of a complete charger are required.
References
A. S. M. M. Hasan, “Electric rickshaw charging stations as distributed energy storages for integrating intermittent renewable energy sources: A case of Bangladesh,” Energies, vol. 13, no. 22, Nov. 2020.
M. Al-Amin and M. Sahabuddin, “High penetration of electric autorickshaw on national power system and barriers against the adoption of solar energy: A case study in Bangladesh,” Cleaner Engineering and Technology, vol. 14, Jun. 2023.
M. J. Al Hossain, M. Z. Hasan, M. Hasanuzzaman, M. Z. R. Khan, and M. Ahsan Habib, “Af-fordable electric three-wheeler in Bangladesh: Prospects, challenges, and sustainable solutions,” Sustainability, vol. 15, no. 1, Dec. 2023.
S. Rana, F. Hossain, S. S. Roy, and S. K. Mitra, “The role of battery operated auto-rickshaw in the transportation system of a city,” Journal of Asian Electric Vehicles, vol. 11, no. 1, pp. 1635–1644, Jun. 2013.
R. Basri, T. Khatun, M. S. Reza, and M. M. H. Khan, “Changing modes of transportation: A case study of Rajshahi City Corporation,” Bangladesh Journal of Political Economy, vol. 31, no. 3, pp. 325–344, Jun. 2016.
K. R. Rahaman, B. Mallick, R. Priodarshini, W. I. Shakil, and M. Z. Hossain, “COVID-19 burdens on livelihood opportunities: A study of easy-bike drivers in Rangpur City, Bangladesh,” World, vol. 3, no. 3, pp. 389–402, Jul. 2022.
Editorial, “Regulating battery rickshaws necessary,” The Daily Star, Aug. 14, 2026.
S. Shahrukh, “Millions of battery vehicles fuel power theft, lead pollution,” Dhaka Tribune, Jan. 18, 2026.
G. Mowla, “Battery-run rickshaws strain Bangladesh’s power grid,” Dhaka Tribune, Apr. 27, 2026.
M. R. Awal, A. K. M. N. Islam and M. Z. R. Khan, “Bangladesh power system peak demand shaving through demand side management of the battery operated easy bike load,” 2019 4th International Conference on Electrical Information and Communication Technology (EICT), Khulna, Bangladesh, 2019, pp. 1–6.
M. H. Sohel, F. Hossain, S. Roy, and S. K. Mitra, “Energy consumption by battery-operated auto-rickshaws,” Daffodil International University Journal of Science and Technology, vol. 8, no. 2, Jul. 2013.
Bonik Barta, “Battery-powered rickshaws create major traffic, energy challenges for government,” Aug. 14, 2026.
M. M. H. Shamim, M. K. Mahmud, and K. G. Moazzem, “Performance evaluation of a 20-kW solar-powered EV charging station in Bangladesh: A post commissioning review,” Energy Conversion and Management: X, vol. 29, Jan. 2026.
Coastal Livelihood and Environmental Action Network (CLEAN), “Easy Bike: A savior for the power sector of Bangladesh,” May 2024.
M. J. Islam, “‘Bangla Tesla’ boom drains nearly Tk4,000 crore in power theft a year in Dhaka,” The Business Standard, Dec. 3, 2025.
M. A. Muyeed, M. H. Oeishee, and A. S. M. Mohsin, “Cost-benefit and net zero impact analysis of PV-grid-battery systems for EV charging stations in Bangladesh,” Energy Conversion and Management: X, vol. 28, Oct. 2025.
A. Mallik and A. Arefin, “Micro hybridized auto-rickshaw for Bangladesh: A solution to green energy vehicle,” The Open Mechanical Engineering Journal, vol. 12, no. 1, pp. 124–137, May 2018.
S. R. Bhuiyan, “Can solar power help solve Bangladesh’s auto-rickshaw electricity theft crisis?,” The Business Standard, Jan. 4, 2026.
M. R. Awal, M. M. Rahman, A. K. M. N. Islam, J. Al-Hossain, and M. Z. R. Khan, “Energy consumption analysis of electric three wheelers in Bangladesh,” in 2019 IEEE International Conference on Power, Electrical, and Electronics and Industrial Applications (PEEIACON), Dhaka, Bangladesh, 2019, pp. 35–38.
S. Abdullah-Al-Nahid, T. Jamal, T. Aziz, A. H. Bhuiyan, and T. A. Khan, “Additive linear modelling and genetic algorithm based electric vehicle outlook and policy formulation for decarbonizing the future transport sector of Bangladesh,” Transport Policy, vol. 136, pp. 21–46, Jun. 2023.
A. Roy, R. B. Patil, and R. Sen, “The effect of fast charging and equalization on the reliability and cycle life of the lead acid batteries,” Journal of Energy Storage, vol. 55, Nov. 2022.
P. Ruetschi, “Aging mechanisms and service life of lead–acid batteries,” Journal of Power Sources, vol. 127, no. 1–2, pp. 33–44, Mar. 2004.
UNB, “Battery-run rickshaws continue to operate amid massive power cuts,” Dhaka Tribune, Jul. 25, 2022.
Centre for Policy Dialogue (CPD), “Terms of reference (ToR) for a 20 kW solar charging station for electric vehicles in the rural areas of Bangladesh,” CPD, Dhaka, Bangladesh, Nov. 19, 2024.
A. K. Podder et al., “Feasibility assessment of hybrid solar photovoltaic-biogas generator based charging station: A case of easy bike and auto rickshaw scenario in a developing nation,” Sustainability, vol. 14, no. 1, Dec. 2021.
R. Redwan, M. Hasan, A. Nadia, M. S. Khan, N. A. Chowdhury, and N.-U.-R. Chowdhury, “Design analysis and techno-economic assessment of a photovoltaic-fed electric vehicle charging station at Dhaka-Mawa expressway in Bangladesh,” Energy Conversion and Management: X, vol. 24, Oct. 2024.
M. A. Arefin and A. Mallik, “Numerical investigation of solar and wind energy assisted plugged in hybridized engine driven auto-rickshaw/three-wheeler,” AIMS Energy, vol. 6, no. 2, pp. 358–375, 2018.
S. A. Gorji, H. G. Sahebi, M. Ektesabi, and A. B. Rad, “Topologies and control schemes of bidirectional DC–DC power converters: An overview,” IEEE Access, vol. 7, pp. 117997–118019, 2019.
S. Chakraborty, H.-N. Vu, M. M. Hasan, D.-D. Tran, M. El Baghdadi, and O. Hegazy, “DC-DC converter topologies for electric vehicles, plug-in hybrid electric vehicles and fast charging stations: State of the art and future trends,” Energies, vol. 12, no. 8, Apr. 2019.
I. Alhurayyis, A. Elkhateb, and J. Morrow, “Isolated and nonisolated DC-to-DC converters for medium-voltage DC networks: A review,” IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 9, no. 6, pp. 7486–7500, Dec. 2021.
T. Sutikno, R. A. Aprilianto, and H. S. Purnama, “Application of non-isolated bidirectional DC–DC converters for renewable and sustainable energy systems: A review,” Clean Energy, vol. 7, no. 2, pp. 293–311, Mar. 2023.
L. A. D. Ta, N. D. Dao and D. -C. Lee, “High-Efficiency Hybrid LLC Resonant Converter for On-Board Chargers of Plug-In Electric Vehicles,” in IEEE Transactions on Power Electronics, vol. 35, no. 8, pp. 8324–8334, Aug. 2020.
A. Rajabi, F. M. Shahir, A. Rajaei, and R. Sedaghati, “A non-isolated high step-up DC-DC converter for electric vehicle (EV): Analysis and design,” IET Conference Proceedings, vol. 2022, no. 3, Jun. 2022.
A. Rajabi, F. M. Shahir, and R. Sedaghati, “New unidirectional step-up DC-DC converter for fuel-cell vehicle: Design and implementation,” Electric Power Systems Research, vol. 212, Nov. 2022.
O. C. Onar, J. Kobayashi, D. C. Erb, and A. Khaligh, “A bidirectional high-power-quality grid interface with a novel bidirectional noninverted buck–boost converter for PHEVs,” IEEE Transactions on Vehicular Technology, vol. 61, no. 5, pp. 2018–2032, Jun. 2012.
M. Yaqoob, K. H. Loo, and Y. M. Lai, “Extension of soft-switching region of dual-active-bridge converter by a tunable resonant tank,” IEEE Transactions on Power Electronics, vol. 32, no. 12, pp. 9093–9104, Dec. 2017.
A. Khaligh and S. Dusmez, “Comprehensive topological analysis of conductive and inductive charging solutions for plug-in electric vehicles,” IEEE Transactions on Vehicular Technology, vol. 61, no. 8, pp. 3475–3489, Oct. 2012.
E. Apostolaki-Iosifidou, P. Codani, and W. Kempton, “Measurement of power loss dur-ing electric vehicle charging and discharging,” Energy, vol. 127, pp. 730–742, May. 2017.
IEEE, IEEE Standard Definitions for the Measurement of Electric Power Quantities Under Sinusoidal, Nonsinusoidal, Balanced, or Unbalanced Conditions, IEEE Std 1459-2010, Mar. 2010.
Joint Committee for Guides in Metrology (JCGM), Evaluation of Measurement Data – Guide to the Expression of Uncertainty in Measurement, JCGM 100:2008, 2008.
fx-rate.net, “US Dollar to Bangladeshi Taka exchange rate,” Sep. 19, 2026.
The Financial Express, “BPDB bent on hiking power price by 21pc,” The Financial Express, May 21, 2026.
Bonik Barta, “Power tariff hike proposal sparks fierce opposition at public hearing,” May 21, 2026.
Prothom Alo, “Power tariff rises by 16.68pc from June,” Jun. 3, 2026.
The Bangladesh Today, “Electricity prices raised by 16.68pc, adding fresh pressure on con-sumers,” The Bangladesh Today, Jun. 2026.
The Business Standard, “Stakeholders slam PDB’s proposal to raise bulk power tariff,” The Business Standard, May 22, 2026.
A. Rahman, “Power prices up 16.7% on average,” The Daily Star, Jun. 4, 2026.
R. W. Erickson and D. Maksimovic, Fundamentals of Power Electronics, 2nd ed. Norwell, MA, USA: Kluwer Academic Publishers, 2001.
J. Martis, “Push–pull converter transformer maximum efficiency optimization,” in Mechatronics 2017: Recent Technological and Scientific Advances. Cham, Switzerland: Springer, 2017, pp. 211–218.
C. W. T. McLyman, Transformer and Inductor Design Handbook, 3rd ed. New York, NY, USA: Marcel Dekker, 2004.
W. G. Hurley, W. H. Wölfle, and J. G. Breslin, “Optimized transformer design: Inclusive of high-frequency effects,” IEEE Transactions on Power Electronics, vol. 13, no. 4, pp. 651–659, 1998.
R. Petkov, “Optimum design of a high-power, high-frequency transformer,” IEEE Transactions on Power Electronics, vol. 11, no. 1, pp. 33–42, Jan. 1996.
C. P. Steinmetz, “On the law of hysteresis,” Transactions of the American Institute of Electrical Engineers, vol. 9, no. 1, pp. 3–64, 1892.
J. Reinert, A. Brockmeyer and R. W. De Doncker, “Calculation of losses in ferro- and ferrimagnetic materials based on the modified Steinmetz equation,” Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting, Phoenix, AZ, USA, 1999, pp. 2087-2092 vol. 3.
P. L. Dowell, “Effects of eddy currents in transformer windings,” Proceedings of the Institution of Electrical Engineers, vol. 113, no. 8, pp. 1387–1394, 1966.
C. R. Sullivan, “Computationally efficient winding loss calculation with multiple windings, arbitrary waveforms, and two- or three-dimensional field geometry,” IEEE Transactions on Power Electronics, vol. 16, no. 1, pp. 142–150, Jan. 2001.
S. A. Ansari, J. N. Davidson, and M. P. Foster, “FEA-based optimisation of an inserted-shunt integrated planar transformer for a bidirectional CLLLC resonant converter,” IET Power Electronics, vol. 18, no. 1, Mar. 2025.
H. Qin, J. W. Kimball and G. K. Venayagamoorthy, "Particle swarm optimization of high-frequency transformer," IECON 2010 - 36th Annual Conference on IEEE Industrial Electronics Society, Glendale, AZ, USA, 2010, pp. 2914–2919.
J. R. Banumathya and R. Veeraraghavalu, “High-frequency transformer design and optimization using bio-inspired algorithms,” Applied Artificial Intelligence, vol. 32, no. 7-8, pp. 707–726, 2018.
E. L. Barrios, A. Ursúa, L. Marroyo, and P. Sanchis, “Analytical design methodology for litz-wired high-frequency power transformers,” IEEE Transactions on Industrial Electronics, vol. 62, no. 4, pp. 2103–2113, Apr. 2015.
Y. Liu et al., “Calculation method of winding eddy-current losses for high-voltage direct current converter transformers,” IET Electric Power Applications, vol. 10, no. 6, pp. 488–497, Jul. 2016.
C. R. Sullivan, “Optimal choice for number of strands in a litz-wire transformer winding,” IEEE Transactions on Power Electronics, vol. 14, no. 2, pp. 283–291, Mar. 1999.
D. C. Meeker, “An improved continuum skin and proximity effect model for hexagonally packed wires,” Journal of Computational and Applied Mathematics, vol. 236, no. 18, pp. 4635–4644, Dec. 2012.
Xi Nan and C. R. Sullivan, "Simplified high-accuracy calculation of eddy-current loss in round-wire windings," 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551), Aachen, Germany, 2004, pp. 873-879.
S. Farhangi and A. Akmal, “A simple and efficient optimization routine for design of high-frequency power transformers,” in Proceeding of the 8th European Conference on Power Electronics and Applications (EPE), Lausanne, Switzerland, 1999.
M. A. Bahmani, Design and optimization of HF transformers for high-power DC-DC applications, Licentiate Thesis, Chalmers University of Technology, Gothenburg, Sweden, 2014.
