Electrical Systems, Batteries & Cold-Start Strategy in Extreme Winter

By: Sammuel MacMullin – Proven Mining Solutions Inc.

When temperatures drop to –30 °C (or lower), electrical problems quickly become one of the most common reasons machines refuse to start or randomly shut down. Modern heavy equipment does not simply need cranking—electrical reliability determines whether systems boot, modules communicate, and engines are even allowed to start.

Cold weather does not “weaken electricity,” but it drastically changes electrical requirements: batteries deliver less usable capacity, engines demand much more electrical draw for cranking, and control electronics continue pulling power during parking. Winter electrical reliability is not simply battery size—it is strategy.

Why Cold Matters Electrically

Cold weather affects electrical performance in three major ways:

↓ Available battery capacity drops

– especially below –20°C

– dramatically below –30°C

↑ Cold-start electrical draw increases

– thicker oil

– higher friction

– colder combustion resistance

→ Batteries recharge more slowly

– alternators need longer runtime

– short idle cycles cannot recover overnight loss

Cold technically improves electrical conductivity, but batteries supply fewer amps while engines demand far more. That imbalance is the root of most winter start failures.

Battery Technology in Northern Mining

Battery Type Cold Performance Notes

Flooded Lead-Acid Poor below –20°C Weak winter performance

AGM Excellent Strongest for extreme cold

Gel Sensitive Not ideal for heavy crank

Lithium (LFP) Poor below 0°C unless heated Internal heating required

Lithium (NMC) Better in cold Higher cost

AGM is not a luxury upgrade in northern conditions—it's required for reliable winter starts.

Parasitic Draw in Winter Parking

Parasitic electrical draw can multiply during long parking periods in camp or yard conditions, especially in extreme cold, because batteries lose usable capacity faster than they are replenished.

Systems that quietly continue drawing power:

• telematics

• GPS

• CAN keep-alive

• HVAC logic

• DEF controllers

• radios

• monitors

And yes—leaving the cab light on or walking away with the work lights blazing is still absolutely “parasitic draw.” We’ve all seen that one.

Most modern equipment includes a night switch (main battery disconnect). Using the night switch correctly is one of the simplest ways to preserve power overnight.

However, Tier 4 Final units require a DEF purge cycle after shutdown. Always wait for the purge indicator before cycling power. DEF freezes at –11°C, so the tank will be frozen by morning—that’s normal—but the purge prevents DEF lines from freezing and cracking.

Operator Tip

If you shut the night switch off before the DEF purge completes, you are setting yourself up for a DEF emissions fault or an engine derate the next day. The tank freezing is normal—the problem is the DEF lines, which will split if purge doesn’t finish.

Once those lines crack, the DEF ends up in the snow instead of the injector, and the machine will not meet emissions. At that point, someone (probably me) has to come out and take half the unit apart to replace DEF lines—while your machine sits losing uptime (and budget).

And yes, if you shut it off early, the only thing thawing tomorrow will be your budget.

Cold-Start Strategy

Proper cold-start is not “just crank harder”—reliable winter start-ups come from warming the entire system.

Reliable sequence

1. Shore-power block heat

2. Battery warmers

3. Coolant or oil heaters

4. Glow-plug or intake-heater cycle

5. Verify voltage under load

6. Then crank

Cold-starts are mechanical, electrical, and thermal all at once.

Harness and Connectors

Extreme cold often causes non-winter-rated insulation to crack. Below –40°C, standard rubber jackets can fracture simply from movement—especially across articulation joints and moving structures.

Cracked insulation is not acceptable to leave unaddressed. Exposed conductors can cause shorts, moisture intrusion, and CAN instability. Use wiring and connectors rated for the temperatures the equipment will operate in. Installing non-winter-rated electrical cable invites premature failure.

Moisture & Frozen Connectors

Moisture inside connectors forces:

• CAN dropouts

• Intermittent electrical faults

• Crank-no-start

• Shutdowns

• False sensor codes

Prevent with:

• Correct sealing

• Correct dielectric grease use

• Proper connector boots

• Warm storage when possible

Dielectric grease is not a universal solution—placement matters.

Daily Checks That Prevent Winter Electrical Failures

1) Cranking voltage <10 V under load

Investigate battery health or parasitic draw if voltage sags significantly.

2) Slow alternator recovery

If voltage takes too long to rise after start, winter charging is already behind.

3) Harness routing

Avoid sharp bends and unnecessary flexing—especially across articulation joints and moving structures. Proper routing dramatically extends insulation life in deep cold and reduces cracked-jacket failures.

Reliable winter electrical performance is more about routing and warming than parts replacement.

Pro Tips from the Field

AGM maintains output in deep cold

Lithium only works reliably with internal heating

Short idle rarely restores winter charge

Use winter-rated wiring during repairs

Warm storage dramatically improves next-day starting

If boosting becomes routine—test parasitic draw

Cold-start is a system, not a component

Advanced Technician Tip (Voltage, Current & Cold Cranking)

Low battery voltage combined with increased cranking resistance forces the starter to draw more current than usual. As the battery becomes depleted through repeated start attempts, current demand rises further—which dramatically increases starter-motor failure risk.

Electrical troubleshooting in cold weather should always consider voltage, current, and mechanical resistance together, not as separate problems.

Common Winter Electrical Mistakes

• Replacing alternators before testing draw

• Installing non-winter-rated components

• Cutting glow-plug or intake-heater cycles short

• Ignoring battery warmers

• Expecting short idle to recharge

• Winter electrical reliability is a program, not a repair.

🔧 Proven Mining Has You Covered

Electrical reliability is safety—not just starting. Proven Mining provides cold-weather electrical inspection, parasitic-draw analysis, harness assessment, and startup planning to keep fleets reliable in extreme northern conditions.

Proven Mining Solutions. Trusted on contract, proven in the field.

From building inspection routines to operator training and data-based wear tracking, Proven Mining Solutions keeps your equipment rolling safely and cost-effectively.

📞 587-723-8777🌐 provenmining.ca