Owner guide · Chicago Northside Toyota · Chicago, IL
Toyota Tundra Battery Guide
Where the Tundra Hybrid's 12-volt battery is and which replacement it needs, the gas Tundra's replacement rules, how to jump start either truck and how to check the voltage, from Toyota's Tundra and Tundra Hybrid owner's manuals, read November 10, 2026.
Rear seatHybrid: left-hand side, under
LN2Hybrid case size, 55Ah / 345A
12.0 V+Open voltage at 68°F
5 A max.Slow charge rate
What battery does a Toyota Tundra use?
Toyota's Tundra Hybrid owner's manual puts the 12-volt battery in the left-hand side under the rear seat and calls for an LN2 case size, 55Ah or greater (20HR) and 345A or greater (CCA), ventilation type calcium with a handle. The gas Tundra manual says to match the case size of the battery already fitted, with an equivalent 20HR capacity or greater and a battery built for the Stop & Start system.
Tundra Hybrid 12-volt battery specifications
| Item | Owner's manual says |
|---|---|
| Location | Left-hand side under the rear seat (raise the bottom cushion, then remove the battery cover) |
| Replacement case size | Same as the previous battery (LN2) |
| 20-hour rate capacity (20HR) | Equivalent (55Ah) or greater |
| Performance rating (CCA) | Equivalent (345A) or greater |
| Battery type | Ventilation type calcium battery that conforms to European regulations, with a handle |
| Open voltage at 68°F (20°C) | 12.0 V or higher (turn the power switch off and turn on the high beam headlights for 30 seconds) |
| Charging rate | 5 A max. |
| Jump starting point | Exclusive jump starting terminal under the hood (open the fuse box cover, then the terminal cover) |
From Toyota's Tundra Hybrid Owner's Manual (OM0C052U), pages 463, 529-532 and 545, read November 10, 2026. The manual does not print a model year; check the manual that came with your vehicle.
Gas Tundra battery
| Item | Owner's manual says |
|---|---|
| Case size | Same as the previous battery |
| 20-hour rate capacity (20HR) | Equivalent or greater |
| Battery type | Conforms to European regulations; a genuine battery designed for the Stop & Start system, or one with equivalent specifications |
| Open voltage at 68°F (20°C) | 12.0 V or higher (turn the engine switch off and turn on the high beam headlights for 30 seconds) |
| Charging rates | Quick charge 15 A max.; slow charge 5 A max. |
| Jump starting point | Positive (+) battery terminal under the hood (open the terminal cover and remove the engine cover) |
From Toyota's Tundra Owner's Manual (OM0C051U), pages 537-539 and 551, read November 10, 2026. The manual does not list a case size or CCA figure for the gas Tundra. It warns that with an unsupported battery, Stop & Start functions may be restricted, battery performance may decrease and the engine may not be able to restart.
How to jump start a Tundra
If the battery is discharged, both manuals say you can jump start the truck with jumper (or booster) cables and a second vehicle with a battery, or call your Toyota dealer or a qualified repair shop. The gas Tundra steps, in short:
- Confirm that the electronic key is being carried. Depending on the situation, the alarm may activate and the doors may lock when the cables are connected.
- Open the hood and the positive (+) battery terminal cover.
- Remove the engine cover: lift its edge to disengage the fixed pins, then pull it towards you.
- Connect a positive cable clamp to the positive (+) battery terminal on your vehicle and the other end to the positive (+) terminal on the second vehicle. Connect a negative cable clamp to the negative (-) terminal on the second vehicle and the other end to a solid, stationary, unpainted metallic point away from the battery and any moving parts, as the manual shows.
- Start the engine of the second vehicle, increase its engine speed slightly and hold it there for about 5 minutes to recharge your battery.
- Open and close any of the doors of your vehicle with the engine switch OFF.
- Keeping the second vehicle's engine speed up, start your engine by turning the engine switch to ON.
- Once the engine has started, remove the cables in the exact reverse order from which they were connected, then reinstall the engine cover.
On the Tundra Hybrid, you open the hood and the fuse box cover, open the exclusive jump starting terminal cover, remove the engine cover and connect the positive cable to that terminal, then start the hybrid system by turning the power switch to ON; afterwards, reinstall the engine cover, close the terminal cover and reinstall the fuse box cover. Both manuals say to have the truck inspected at your Toyota dealer as soon as possible once it starts. Neither truck can be started by push-starting, and the manuals say to make sure the cables do not become entangled in the cooling fan. To avoid igniting gas from the battery, the manuals say to make sure each cable is on the correct terminal, keep the other end of the cable on the + terminal away from other parts and metal surfaces such as brackets or unpainted metal, never let the + and - clamps touch, and keep smoking, matches, lighters and open flame away from the battery. When removing the battery terminals, always remove the negative (-) terminal first.
Checking and charging the battery
From the Tundra and Tundra Hybrid owner's manuals:
Look at the exterior
Make sure the terminals are not corroded and that there are no loose connections, cracks or loose clamps.
Check the voltage
Turn the switch off and turn on the high beam headlights for 30 seconds before checking. The open voltage should be 12.0 V or higher at 68°F (20°C).
Charge in the open
Recharging produces flammable, explosive hydrogen gas. Always charge in an open area, not a garage or closed room without enough ventilation. If the battery is still in the truck, disconnect the ground cable, and keep the charger's power switch off while connecting and disconnecting its cables.
Never while running
Do not recharge the battery while the engine or hybrid system is operating, and turn off all accessories. The Hybrid manual lists a 5 A max. charging rate.
After reconnecting
The smart key may not unlock the doors right away, so use the wireless remote control or the mechanical key. On the Hybrid, start the hybrid system with the power switch in ACC, then depress the brake pedal and confirm you can shift into each position. Information stored in the ECU is cleared and some systems may need initialization.
From Toyota's Tundra Owner's Manual (OM0C051U) pages 474-476, 539 and 551 and Tundra Hybrid Owner's Manual (OM0C052U) pages 463-465, 531-532 and 545, read November 10, 2026. The manuals also say to wear safety glasses, avoid sparks from tools touching the terminals and keep children away from the battery.
Replacing a Tundra battery
Use a battery with the same case size as the one fitted. The manuals say that if the sizes differ, the battery cannot be properly secured, and if the 20-hour rate capacity is low, the battery may discharge even when the truck sits for only a short time, and the engine or hybrid system may not be able to start.
For the Tundra Hybrid, the manual says to use a 12-volt battery designed for the vehicle, because otherwise hydrogen gas may enter the passenger compartment and cause a fire or explosion, and to reuse the exhaust hose and fit the exhaust hole plug to the new battery; if they are not properly installed, hydrogen gas may leak into the cabin and could ignite. For the gas Tundra, the manual warns that battery fluid (sulfuric acid) may leak when the vent plug and indicator are close to the hold-down clamp.
Removing the battery terminals clears information stored in the ECU, so the manuals say to contact your Toyota dealer before removing them, and to always remove the negative (-) terminal first.
Chicago Northside Toyota service hours
| Days | Hours |
|---|---|
| Mon-Fri | 7 a.m.-6 p.m. |
| Sat | 8 a.m.-5 p.m. |
| Sun | closed |
From Chicago Northside Toyota's website, November 11, 2026. Holiday hours can differ.
Toyota Tundra battery FAQ
What battery does the Tundra Hybrid use?
Toyota's Tundra Hybrid owner's manual calls for a 12-volt battery with the same case size as the previous one (LN2), 55Ah or greater (20HR) and 345A or greater (CCA): a ventilation type calcium battery with a handle that conforms to European regulations.
Where is the 12-volt battery on a Tundra Hybrid?
The manual says it is located in the left-hand side under the rear seat. Raise the bottom cushion, then remove the battery cover with a flat-head screwdriver or the mechanical key. For jump starting, the manual uses an exclusive jump starting terminal under the hood, inside the fuse box cover.
What battery does a gas Tundra need?
The gas Tundra owner's manual says to use a battery with the same case size as the previous battery and an equivalent 20-hour rate capacity (20HR) or greater, conforming to European regulations. It also calls for a genuine battery designed for the Stop & Start system or one with equivalent specifications. It does not list a case size or CCA figure, so match the battery in your truck or ask our service team.
How do I jump start a gas Tundra?
With jumper cables and a second vehicle with a battery: confirm the electronic key is being carried, open the hood and the positive (+) battery terminal cover, remove the engine cover, and connect the cables to your positive terminal, the second vehicle's terminals and a solid, stationary, unpainted metallic point away from the battery and moving parts. Run the second vehicle's engine slightly faster for about 5 minutes, open and close any door with the engine switch OFF, then start your engine.
What voltage should a Tundra battery have?
Both manuals list an open voltage of 12.0 V or higher at 68°F (20°C), checked after turning the switch off and turning on the high beam headlights for 30 seconds. The gas manual lists charging rates of 15 A max. (quick charge) and 5 A max. (slow charge); the Hybrid manual lists 5 A max.
Can a Tundra be push-started?
No. The gas Tundra manual says the engine cannot be started by push-starting, and the Tundra Hybrid manual says the same of the hybrid system.
Can Chicago Northside Toyota replace my Tundra battery?
Yes. Both manuals point owners to a Toyota dealer for battery replacement information. Our service team at 6042 N. Western Ave. in Chicago can test the battery and fit the right one for your Tundra. See the service hours above or schedule online.
Tundra battery weak or flat?
Bring it to Chicago Northside Toyota, 6042 N. Western Ave. in Chicago. Our service team can test the battery and replace it with the right one for your Tundra.
Sources
Battery location, replacement requirements, jump start steps, charging and voltage figures are from Toyota's Tundra and Tundra Hybrid owner's manuals, read November 10, 2026. Your own owner's manual is the final word for your vehicle. Address and hours are from Chicago Northside Toyota's own website. Photo is illustrative.
- Tundra Owner's Manual (OM0C051U): checking and charging the battery (pp. 474-476), jump starting, discharge and replacement requirements (pp. 536-540), electrical system specifications (p. 551), Toyota, read November 10, 2026
- Tundra Hybrid Owner's Manual (OM0C052U): 12-volt battery location, cover and charging (pp. 463-465), jump starting and replacement requirements (pp. 529-534), electrical system specifications (p. 545), Toyota, read November 10, 2026
- Address and service hours, Chicago Northside Toyota, November 11, 2026
