The practical answer.
Measure the complete battery-side parked load after the cart reaches its approved resting state, including the DC-DC converter and any devices that remain awake. Key-off does not establish zero consumption. Review the converter’s actual input range, enable behavior and installation requirements, then use a defined storage-energy budget and the vehicle and battery manufacturers’ instructions. Do not tap part of a series battery string or disconnect required circuits as an improvised remedy.
Map the accessory circuit separately from traction
List lights, displays, communications, tracking devices, audio and other installed equipment. Identify whether each is supplied through a converter, a dedicated source or another approved arrangement. Record which circuits remain active with the key off and which functions require them. A cart can appear quiet while several small loads continue to consume energy. The relevant parked state must be defined by the vehicle documentation, not by whether a dashboard screen is dark.
For a series battery assembly, drawing an accessory supply from only part of the string applies unequal loading to the selected portion. Do not assume a balancing function makes such a connection acceptable. Ask the qualified installer for the approved accessory architecture and complete wiring information. This is especially important when an older vehicle has undocumented modifications; a battery conversion should not inherit an unknown connection simply because the accessories still turn on.
Read the converter specification at the correct level
A converter needs an approved input operating window, output capability, enable behavior and installation conditions. MEAN WELL's SD-350 specification is an example of documentation that distinguishes input ranges, load ratings, protection and environmental conditions. It is an industrial component reference, not a recommendation or a golf-cart compatibility approval. Review the exact proposed converter's vehicle suitability and installation requirements with its supplier and the responsible installer.
Do not confuse rated output power with parked input current, or shutdown behavior with physical isolation. Some documents provide no useful standby number for the intended installation. Treat that as a question to resolve through supplier evidence and an approved measurement, not as a zero. Confirm the behavior with the actual accessories connected, including any control or communication wiring that could change the converter state or keep another subsystem awake.
| Item | Evidence needed | Common confusion |
|---|---|---|
| Converter input | Actual operating window and installation conditions | Nominal battery label treated as complete compatibility |
| Enable control | Key-off, standby and approved shutdown behavior | Disabled output treated as full isolation |
| Accessory loads | Operating states and periodic wake events | Only visible lights counted |
| Parked current | Battery-side pattern over a defined interval | One instantaneous reading treated as a month-long average |
| Storage plan | Manufacturer instructions and responsible service role | Generic advice substituted for released procedures |
Calculate active and parked energy using explicit assumptions
For a hypothetical active-load example, a 12V accessory draws 6A, giving 72W output. At an explicitly assumed 90% converter efficiency under that load, the input is 80W, or about 2.22A at a hypothetical constant 36V input. Those values are not Jetray or converter ratings. If the efficiency figure already includes the converter's operating losses, do not automatically add the same loss again under a different label.
For a separate hypothetical parked case, an aggregate measured battery-side draw of 0.02A at an assumed constant 36V is 0.72W. Over 24 hours that is 17.28Wh; over 30 days it is about 518Wh. Real voltage, sleep behavior and battery availability vary, so this is a planning sensitivity, not an exact state-of-charge forecast or a recommended storage interval. It shows why a small continuous load deserves attention in a seasonal fleet.
Measure a defined parked state rather than one instant
Have qualified personnel use the vehicle's approved procedure to establish the parked condition, then observe the relevant time window. A tracking device may wake periodically, a controller may take time to settle, and an accessory may behave differently after charging. A single instantaneous reading can miss that pattern. Identify the measurement boundary and distinguish an average over the observed interval from a peak during a wake event.
Preserve the vehicle configuration and what remained connected. If a circuit is investigated separately, record the authorized method and restore the approved configuration afterward. Do not bypass protective equipment, change undocumented settings or disable required functions to obtain a favorable number. The useful report explains why the parked draw occurs and which responsible team can assess an approved remedy, rather than simply assigning every unexplained loss to the battery.
Turn a drain finding into an operating record
Compare the observed pattern with the storage and return-to-service instructions for the actual cart and battery. Ask which components have approved shutdown, isolation or periodic maintenance procedures and who may perform them. A key-off procedure, a service disconnect and a battery storage mode can have different purposes. Do not assume that one is a substitute for another or that a generic internet battery percentage is an approved storage target.
The Jetray 36V product reference, 36V LiFePO4 evaluation and 48V-class system inquiry require different compatibility discussions. None establishes the parked consumption of an installed cart. Send the accessory list, converter identity, approved wiring information and observed parked-load record with an inquiry. Request the actual battery's relevant operating and storage documents, then have the vehicle team decide how the complete installation will be managed during inactive periods.
Frequently asked questions
Does turning off the cart key isolate the battery?
Not necessarily. The approved vehicle architecture determines which loads remain connected. Observe the actual parked state and follow its documentation. Do not infer isolation from a dark screen or assume that physically disconnecting a circuit is an approved operating procedure.
Can a converter's headline efficiency predict storage drain?
No. The quoted efficiency applies under stated conditions and may not describe standby, remote-off or periodic wake behavior. Ask for the relevant state-specific data and measure the installed arrangement using an approved method. Avoid converting a full-load marketing figure into an unsupported parked-current value.
Will a larger battery solve an accessory-drain complaint?
It may change the arithmetic time available, but it does not identify an unexpected load or make the wiring appropriate. First establish the actual configuration, current pattern and approved storage procedure. A capacity change must still be reviewed for the vehicle, controller, charger and installation.
Sources & further reading
- MEAN WELL SD-350 DC-DC converter specification, 2024-11-22 ↗
- TI BQ76952 battery monitor and protector: separate charge/discharge protection ↗
- Jetray original product and application navigation ↗
Prepared from primary technical sources and original engineering analysis. All numerical scenarios are hypothetical planning examples, not Jetray measurements, customer cases or verified product ratings. Catalogue links are evaluation references; exact application suitability and approval require documented project validation.
Prepared for the golf cart battery projects collection. General engineering guidance does not replace a model-specific datasheet or application validation. Source review: 5 November 2026.