Shaanxi Fenghan Trading Co., Ltd. supplies the SAGMOTO i5 electric light and medium truck to urban delivery and municipal fleets moving away from diesel, and the high-voltage system is where that transition demands a new discipline, because a 100 to 140 kWh pack running at several hundred volts is not a mechanical fault you can feel with a wrench. The i5 uses a permanent magnet motor rated 120 to 160 kW with a claimed urban range near 200 km, and its high-voltage connectors, battery coolant loop and charging port are the components that decide whether the truck stays safe and on the road. This guide gives EV fleet workshops the inspection schedule, the test procedure and the technician safeguards to keep an i5 compliant with high-voltage safety from day one.
1. High-Voltage Connector Inspection Schedule
The orange high-voltage connectors between the battery, the motor controller, the motor and the charging inlet should be visually inspected every 10,000 km or 250 hours, and torque-checked every 40,000 km or 1,000 hours, because vibration on urban potholed routes loosens the locking cam and lets the seal weep. Look for cracked housing, a dislodged secondary lock, discolouration from arcing at the terminals, and any sign the orange boot has been pushed back exposing the contact. A connector that has lost its lock will not necessarily fault immediately but will arc under load, and arcing at several hundred volts welds contacts and starts fires.
Always re-seat a disconnected HV connector with the system de-energised and the secondary lock fully engaged, and apply the specified thread treatment only where the manual calls for it, because over-tightening cracks the housing while under-tightening invites the looseness you are trying to prevent. Tag every HV junction opened during service with the date and the technician badge, so the next inspection can see at a glance which connectors were last disturbed and whether a fault traces to a recent intervention.
Key takeaway: Inspect i5 HV connectors every 10,000 km, torque them every 40,000 km, and never re-seat one while energised, because a loose orange lock arcs at several hundred volts and welds its own contacts.
2. Dielectric and Insulation Resistance Testing
Dielectric testing confirms the high-voltage circuits are isolated from the chassis, and on the i5 it should be performed at every major service and after any HV component replacement or flood exposure. Use a calibrated megohmmeter set to the specified test voltage, typically 1,000 V DC for this class, with the system isolated and the manual's test points followed exactly, measuring resistance between each HV conductor and the vehicle ground. A healthy i5 reads in the megaohm range well above the manufacturer threshold; a reading in the kiloohm band means moisture, cracked insulation or a failing connector that must be found before the truck is energised.
Insulation resistance testing is also the gate before any roadside recovery, because a pack that has been in a collision may have internal damage invisible from outside. Record the value against the VIN and trend it, because a slow fall over services predicts the failure a sudden drop confirms, and a fleet that trends insulation catches a degrading harness before it arcs. Never skip the test after a coolant leak near an HV junction, because coolant is conductive enough to bridge the isolation the megohmmeter is there to prove.
3. Battery Coolant Loop Maintenance
The i5 battery pack is kept in its temperature window by a dedicated dielectric coolant loop separate from any cabin circuit, and this loop is the reason the pack holds range and life through a hot delivery summer. Inspect the loop every 20,000 km for pressure hold, for coolant level at the expansion bottle, and for any weep at the pack inlet and outlet fittings, because a slow loss raises cell temperature and the controller responds by trimming power to protect the pack. Use only the specified dielectric coolant, never automotive antifreeze, because a conductive mix defeats the very isolation the HV system depends on.
Flush and refill the loop on the scheduled interval, typically every 4 years or 200,000 km, and bleed it fully so no air pocket sits against a cell, because an air gap is a hot spot that ages that cell faster than its neighbours and unbalances the pack. After any pack removal, pressure-test the loop to the manual's figure and confirm no crossing of the dielectric and low-voltage circuits, since a cracked heat-exchanger core would put coolant where it can bridge HV to ground.
Key takeaway: The i5 battery loop uses dielectric coolant only, never antifreeze, and a slow level loss trims power to protect the pack, so pressure-test it every 20,000 km and trend the reading.
4. Charging Port Wear and IP Rating
The CCS charging inlet on the i5 takes thousands of plug cycles across a fleet life, and the contact pins wear, the latch springs fatigue and the IP-rated seal around the port degrades from weather and forced plugs. Inspect the port every 10,000 km for bent pins, blackening from arcing, a loose latch and any gap in the sealing gasket, because a port that loses its IP rating lets water track into the HV contactor and trips a fault at the worst moment, mid-charge. Clean the pins only with the specified non-conductive wipe and never lubricate them, since a film invites carbon and arcing.
Train drivers to seat the connector fully until the latch clicks and to report any burning smell or heat at the handle, because a warm plug is the early signature of a resistive contact that will only worsen. Where the i5 works in rain or wash bays, verify the port cover seats and consider a sill-mounted boot, because preserving the IP rating is cheaper than replacing a contactor that water has already reached.
5. Technician PPE and Lock-Out-Tag-Out
No high-voltage work on the i5 begins without the procedure that makes it safe: isolate the pack, verify zero voltage at the test points with a certified HV meter, apply the lock-out-tag-out device, and only then open a junction. The technician wears rated HV gloves with leather protectors, HV-rated insulated tools, eye protection and a barrier apron, and works with a second person within call who is also HV-aware. The lock-out-tag-out device stays until the work is closed out and the insulation test passes, and the tag carries the technician name and the time so nobody re-energises past it.
A common failure mode is assuming the pack is dead because the contactor clicked off; the manual's verification step exists because a failed contactor or a capacitor can still hold a lethal charge. The SAGMOTO export program bundles a two-day high-voltage safety course with the i5, covering exactly this sequence, and fleets should treat the certificate as a condition of any workshop touching the orange loom, because an untrained hand on a 100 kWh pack is a liability no saving justifies.
6. Tools, PPE and Interval Reference
The tables below give a fleet the minimum kit to service the i5 high-voltage system safely and the schedule that keeps it compliant. Adjust intervals for harsh climate where the manual allows.
| Task | i5 interval | Trigger |
|---|---|---|
| HV connector visual inspect | 10,000 km or 250 h | Every service |
| Connector torque check | 40,000 km or 1,000 h | Scheduled |
| Insulation resistance test | 40,000 km | After HV work or flood |
| Battery coolant loop check | 20,000 km | Pressure and level |
| Charge port inspect | 10,000 km | Every service |
| Loop flush and refill | 4 years or 200,000 km | Scheduled |
| Item | Specification | Purpose |
|---|---|---|
| HV insulated gloves | Rated to 1,000 V class | Shock protection |
| Calibrated megohmmeter | 1,000 V DC test | Insulation test |
| HV insulated tools | Double-rated handles | Live-safe service |
| Lock-out-tag-out kit | Personalised tag | Energy isolation |
| Dielectric coolant | Specified only | Battery loop |
| HV warning signs | Standard orange | Bay demarcation |
7. Climate and Seasonal Considerations
The i5 high-voltage system behaves differently across the climate bands a delivery fleet actually faces, and the maintenance plan should follow the season rather than a single fixed calendar. In hot coastal summers the battery coolant loop carries more heat and the charge port seal hardens faster under UV, so move the loop pressure check and the port inspection to the front of the 10,000 km slot and watch coolant level for any drift that signals a weep before it becomes a fault. In humid monsoon conditions the IP rating of every orange connector is under steady assault from condensation, so verify the secondary locks after any wash-bay exposure and trend the insulation resistance more often, because moisture is the one fault the megohmmeter exists to catch early.
Cold CIS winters bring a different risk: the dielectric coolant must retain its low-temperature rating so the loop never gels and starves a cell of heat exchange, and the charge port latch stiffens, so train drivers to seat the plug gently rather than force a cold latch that cracks the housing. For fleets that park i5 trucks through a long off-season, store them at a partial state of charge per the manual, isolate the pack with lock-out-tag-out, and perform a full insulation test before re-energising, because a pack that sat through freeze-thaw cycles deserves verification before it carries a payload again. These climate adjustments keep the scheduled intervals honest and stop the environment from quietly defeating the routine.
8. Conclusion
The SAGMOTO i5 electric truck brings diesel-free urban delivery within reach, but only when the high-voltage system is maintained by a procedure-led workshop rather than a mechanically trained one learning on the job, because the battery pack and its connectors demand isolation discipline that no wrench skill replaces. Inspect the orange connectors every 10,000 km and torque them every 40,000 km, trend the insulation resistance at every major service, keep the dielectric coolant loop sealed and correct, preserve the charge port IP rating, and never open a junction without lock-out-tag-out and rated PPE. The full electric range is detailed with the SAGMOTO new energy electric trucks page, and the routine above keeps a 120 to 160 kW i5 safe and earning through the millions of urban kilometres its pack is built to deliver.