Sharing cab power (2026)
A team cab has one electrical system and two routines. One person runs a CPAP. The other charges a laptop and wants a fan. The fridge does not care who bought the food. The Sleeper Cab Power Planner is where those loads go on one list. Turn on every load that is really on. A plan that only counts one person's gear is a shortfall you meet at 04:00.
The photo is a Peterbilt 379 at a show. It is not an electrical diagram.
One bank, two routines
List the night in the planner:
- The 12 volt fridge, if the socket stays live with the key off. The fridge guide is the box. The amps are the label or the lab figure the planner already names.
- A CPAP on DC or on the inverter, with the humidifier on or off. The CPAP note is why those are different watts.
- Fans, lights, phones, and a laptop for either person. If both laptops charge at once, both belong on the list. The laptop row is one load. Raise the watts or the hours if two bricks are on the inverter together, or count the overlap honestly.
- A heater or bunk cooler only if you mean to run it. It is off by default because it dominates the night.
Usable energy is still amp-hours times voltage times depth of discharge. Fifty percent is the ceiling when the bank cranks the truck. Eighty percent is a planning figure for a lithium house battery. Two people do not get to use 100 percent of a starting bank because there are two of them.
What not to invent
Do not splice a second person's inverter into a circuit you have not identified. Do not backfeed shore power. Company trucks often forbid a new wire. If you cannot add a house battery, the honest result from the planner is a shortfall, and the next step is shore power where the spot has a matching plug, or fewer loads, or an engine-on charge the carrier allows. Idling so two people can run heaters is a fuel and policy question. This page does not tell you to idle. The shore-power guide is the plug, when you have one.
A portable power station is a separate box with its own watt-hour rating. Read that rating. It is not the truck's amp-hour figure, and the photo is not an install.
Agree who can turn a load on while the other person is asleep. A kettle at 02:00 is a shared battery event. Say so before the trip, not during the low-voltage cutoff.
Swipe this table sideways. The page stays put, and the first column stays visible.
| Load | Whose | In the planner |
|---|---|---|
| Fridge | Both, one box | DC amps and hours |
| CPAP | The person who uses it | DC or inverter, humidifier on or off |
| Two laptops | Both, if both charge | Inverter watts for the overlap |
| Fan or light | Whoever leaves it on | DC amps and hours |
| Heater | Only if you mean it | Inverter, and usually shore power |
Add both routines before you call the night covered
A team night is one battery and two sets of loads. Write both down. A fridge, one CPAP or two, two phones, a laptop, a fan: if it will be on while the engine is off, it goes on the power planner. The planner's verdict is covers it or does not cover it, in watt-hours and amp-hours. Believe the shortfall. A starting battery that also has to crank the truck in the morning is a bad only plan for that list.
Split the habits, not the physics. One person can be in charge of plugging the fridge in. Both people still count as load. Do not assume the other driver "didn't use much." Ask. The team schedule handoff is a good time to say what ran.
Inverters get sized from the AC label, about 125 percent continuous, on a cable the sheet calls for. The inverter guide is the AIMS class of install versus a small plug-in. A cigarette-plug inverter is the wrong tool for a real CPAP-plus-heater night. The CPAP page is the DC cord if the manual lists one, which saves the inverter loss.
Shore power, when the pedestal matches the cord, is how you stop arguing with the bank. Do not backfeed. Do not coil a loaded cord tight. A reefer is not a spare outlet. The cab and reefer page says to leave the unit on its setpoint unless the truck manual shows a bunk feed.
Skip a private power strip that only one of you knows about, a heater as a comfort default, and two gifts that each take the only live socket. The team gift note is buy two small things or one thing that does not steal the socket. If the planner says short, shorten the night, find shore power, or bring a pack whose label you have read. Do not hope.
| Load | Count it | Leave it out of the guess |
|---|---|---|
| Fridge, CPAP, fan, laptops | Both people's hours | "They probably didn't" |
| Heater | Only on shore power or a bank built for it | Overnight on the starting battery |
| Inverter | 125 percent of the AC label | A cigarette plug for a big load |
| Reefer | Setpoint, not a cab outlet | A tap the manual does not show |
Conclusion
Put both routines on one night in the planner. If the bank is short, believe it. A second person is a second load, not a second battery.
FAQ
Can we split the battery 50/50 in our heads?
You can share the energy. You cannot pretend each person has the full bank. Add the loads.
Does a team truck come with a house battery?
Some do. Many do not. Read the truck. The planner's "lithium house battery" line is a depth of discharge you choose, not a guess about your equipment.
Who pays the inverter loss?
The battery does, for every AC load. A DC CPAP does not. Set the feed to match the cord.