How to Jump Start a Prius (Step-by-Step, All Generations)

Short version: When a Prius won’t start, nothing cranks when you press POWER — and that is normal for how these cars work. The small 12-volt battery’s only job is to wake the computers and connect the hybrid battery; the hybrid battery does the rest. When the 12V is flat, the fix is to jump the 12V at the right point for your generation, get the car to READY, and let it recharge itself for 30 to 60 minutes. On 2004–2015 cars that point is a dedicated terminal in the driver-side under-hood fuse box; on 2016–2022 cars the battery itself is under the hood. Pick your generation below.

First: is it really the 12-volt battery?

When your Prius won’t start, the problem often lies with the 12-volt battery rather than the hybrid battery system. Unlike conventional vehicles, the Prius relies on the 12-volt battery for essential electrical systems, and a discharged battery can leave you stranded. Fortunately, jump starting your Prius is a straightforward process when you understand the unique steps involved. Typically it presents itself like this: Video of bad 12V battery. The pattern we see in the shop every week:

  • The car won’t detect the key fob — you press the door button and nothing happens.
  • The dash throws a dozen warning lights at once, sometimes with messages like “Check Hybrid System.” It looks catastrophic; it usually isn’t.
  • The car won’t enter READY — you press POWER with your foot on the brake and it clicks, flickers, or does nothing.
  • Everything electrical acts possessed: flickering screens, slow windows, chiming.

Not sure whether it’s the little battery or the big hybrid battery? Read our companion article: Prius 12V Battery: Why Your Hybrid Won’t Start — that article is the concept layer for everything on this page, and we won’t repeat it here.

Before you connect anything

  • Do you have a power source — jumper cables plus a donor car, or a jump pack? If not, stop here and text us at 503-969-3134.
  • Can you open the hood? If the hood will not open, stop here.
  • Confirm your generation matches what you’re seeing in the section you pick. If what’s under your hood doesn’t match the description — stop. Don’t guess. Text Atomic Auto at 503-969-3134. One model year (2015 → 2016) completely changes where the battery is and how you connect.
  • Never touch anything orange or under a high-voltage cover. The hybrid battery is irrelevant to this procedure.
  • No smoking or open flame near a lead-acid battery, and eye protection is smart — a charging battery can vent hydrogen gas.

How to Jump Start a 2004–2009 (Gen 2) Prius

  1. Open the hood and locate the jump terminal. Open your Prius hood and locate the fuse block on the driver side — the exclusive jump-starting terminal is inside, under a red cover labeled with a + symbol. Carefully open the cover by following the markings in your engine bay. This protective cover shields the terminals and must be opened to access the positive and negative connection points for your jumper cables. The Prius features a special jump-start terminal instead of traditional battery posts, making the process slightly different from conventional vehicles. This is because the battery is at the right rear of the cargo area, behind a trim panel — and you cannot open the liftback with a dead battery. Always consult your owner’s manual if you’re unsure of the location.
  2. Connect the positive jumper cable. Using a set of jumper cables, connect the positive (red) clamp to the jump-start terminal under the red cover.
  3. Connect the other positive clamp. Attach the other red clamp to the positive terminal of the donor vehicle’s battery or your jump pack. Double-check your polarity before going any further: connecting the cables backwards will blow the main fuse and can even damage the DC/DC converter, which is an expensive repair — far more than the cost of a battery. This is exactly why we recommend a smart jump box like the NOCO GB40: it verifies the connection is correct before it energizes the clamps, so a backwards hookup gives you a warning light instead of a blown fuse.
  4. Connect the negative cables — ground goes on last. Attach the black clamp to the donor battery’s negative terminal, then attach the final black clamp to a solid, unpainted metal bolt or bracket on the Prius engine block. Start the engine of the vehicle providing power and let it run for a few minutes. This allows charge to build up before you attempt to start your Prius. DO NOT USE YOUR PRIUS TO JUMP START OTHER VEHICLES.
  5. Wait and then start the Prius. Wait about 5 minutes so the 12V battery absorbs some charge. Then, with your foot on the brake, press the Power button — on cars with a fob slot, push the fob all the way into the slot first, then brake and press Power. Do not stop when the dash lights up: you must see “READY” appear on your dashboard. A lit dash without “READY” means the car is not actually on and the 12V battery is not charging — the jump will fail and the battery will go flat again. The Prius is charging its 12v battery on its own.
  6. Disconnect cables in reverse order. Once the car is in “READY” mode you can remove the jumper cables: take the negative (black) clamp off the Prius first, then the donor vehicle’s negative clamp, then the donor’s positive clamp, and finally the positive clamp on the Prius jump terminal last.

Want the factory version? How to jump start a 2004-2009 Prius — instructions from the owner’s manual.

Doesn’t match what you’re seeing? Stop — don’t guess. Text us: 503-969-3134.

How to Jump Start a 2010–2015 (Gen 3) Prius

The third-generation Prius works almost the same way. The 12-volt battery lives at the right rear of the cargo area on these cars too, so Toyota again provides a dedicated jump point under the hood — you never need to touch the battery itself to jump start the car.

  1. Open the hood and locate the jump terminal. Find the fuse box on the driver side of the engine bay and open its black plastic cover. Inside is the exclusive jump-starting terminal under a small red flip-up cover marked with a + symbol.
  2. Connect the positive jumper cable. Flip up the red cover and connect the positive (red) clamp to the jump-start terminal.
  3. Connect the other positive clamp. Attach the other red clamp to the positive terminal of the donor vehicle’s battery or your jump pack.
  4. Connect the negative cables. Attach the black clamp to the donor battery’s negative terminal, then attach the final black clamp to a solid, unpainted metal point on the Prius engine — a bolt or bracket on the engine block works well. Double-check your polarity before going any further: connecting the cables backwards on a Gen 3 will blow the main fuse and can even damage the DC/DC converter, which is an expensive repair.
  5. Let it charge, then start the Prius. Run the donor vehicle (or connect the jump pack) for about 5 minutes to let the dead battery absorb some charge. Then put your foot on the brake and press the Power button. When “READY” appears on the dash, the car is on and charging its own 12-volt battery.
  6. Disconnect cables in reverse order. With the car in “READY” mode, remove the negative (black) clamp from the Prius engine first, then the donor’s negative clamp, then the donor’s positive clamp, and finally the positive clamp on the Prius jump terminal. The same warning applies: do not use your Prius to jump start other non-hybrid vehicles.

Want the factory version? How to jump start a 2010-2015 Prius — instructions from the owner’s manual.

Doesn’t match what you’re seeing? Stop — don’t guess. Text us: 503-969-3134.

How to Jump Start a 2016–2022 (Gen 4) Prius, Including the Prime

On the 2016–2022 Prius and Prius Prime, the 12V battery is under the hood on the driver’s side, tucked back near the base of the windshield next to the fuse box. The positive terminal sits under a red flip-up cover. This is a real change from the 2004–2015 cars, which hid the battery in the right rear of the cargo area and gave you a remote jump point in the fuse box instead. On the Gen 4, you connect right at the battery, like a normal car.

If the battery is completely dead, the fob won’t unlock the doors. Use the metal emergency key hidden inside the fob to unlock the driver’s door, then pull the hood release.

  1. Line up your power source. Another car with a 12V battery, or better, a small lithium jump pack. A Prius needs very little current to boot — you’re waking up computers, not cranking an engine — so a compact smart jump box like the NOCO GB40 is plenty, and its reverse-polarity protection is cheap insurance.
  2. Open the hood and find the battery. Driver’s side, back near the windshield. Flip up the red cover on the positive terminal.
  3. Connect the positive (red) clamp to the Prius positive terminal.
  4. Connect the other red clamp to the donor vehicle’s positive terminal (skip this and the next step if you’re using a jump pack).
  5. Connect the black clamp to the donor’s negative terminal.
  6. Connect the last black clamp to bare metal on the Prius — an unpainted bolt or bracket in the engine bay, away from the battery and any moving parts.
  7. Wait about five minutes. If a donor car is providing the jump, start its engine and let it run so the dead battery can absorb some charge. Don’t rush this step.
  8. Foot on the brake, press POWER. Watch for the green READY light on the dash. There’s no engine cranking sound — READY means the car is “running” even in total silence. The gas engine may or may not fire up; either way you’re good.
  9. Disconnect in reverse order: black clamp off the Prius first, then the donor’s black, then the donor’s red, then the red on the Prius. Snap the red terminal cover closed.

Stay away from the hybrid battery. The Gen 4’s high-voltage battery — it lives under the rear seat on these cars — has nothing to do with jump starting, and there is nothing under its covers you should ever touch. The 12V system is the only thing that needs help.

Doesn’t match what you’re seeing? Stop — don’t guess. Text us: 503-969-3134.

What about the Prius c (2012–2019)?

We haven’t published a verified jump-start procedure for the Prius c yet. It’s a different platform from the Prius liftback — the answer for the other generations does not carry over, and we’d rather tell you that than guess. Text us at 503-969-3134 and we’ll walk you through it.

What about the Prius v?

Good news: the Prius v (2012–2017) is built on the same platform as the Gen 3 liftback and jumps exactly the same way — same 12-volt battery at the right rear of the cargo area, same jump-start terminal in the driver-side under-hood fuse box, same steps. Use the 2010–2015 (Gen 3) section above.

After the jump: what READY means and how the car recharges itself

When the dashboard displays “READY,” your Prius is actively charging the 12-volt battery from the hybrid system. You don’t need to drive the vehicle to complete this charging process. Simply leave the vehicle in “READY” mode for 30 to 60 minutes, and the high-voltage hybrid battery will recharge the depleted 12-volt battery. If it was completely flat, give it a few hours — or better, put it on a proper smart charger — and have it tested. Never leave the vehicle in READY inside a garage or enclosed space: the gasoline engine will start on its own, without warning, and the exhaust can fill the space with carbon monoxide.

Once charging is complete and the battery has been restored, take a moment to investigate the cause of the discharge. Check for any lights left on or doors that were left ajar. These simple oversights are often responsible for battery drainage and can be easily prevented.

If you’ve left your Prius unattended during the charging process, you can safely lock the doors using your key fob. For added security, you can remove the metal key from your fob and use it to lock the driver’s door manually without the fob in the car. However, remember that manual locks are less secure than electronic ones. Never leave your vehicle unattended for extended periods in unsafe locations while it’s charging. Even without the key someone can drive it away!

For the full story of why a flat 12V causes such scary symptoms — and how the whole system works — read Prius 12V Battery: Why Your Hybrid Won’t Start.

When to Seek Professional Help

If the 12-volt battery continues to drain even after the charging process, or if your Prius won’t maintain a charge, contact a qualified repair shop. These symptoms may indicate a deeper electrical issue or a faulty battery that requires professional diagnosis and replacement.

You can also run a battery test yourself, just be aware that if your battery is marginal, you can kill it again and we would not recommend doing this test without the ability to jump start the car again. Our friend Carolyn made this nice video years ago showing how you can test it yourself

At Atomic Auto, we specialize in helping Prius owners navigate common issues and maintain their vehicles. Whether you’re dealing with battery problems or need routine maintenance, our team of experts is ready to help. Text us at 503-969-3134 to schedule a diagnostic appointment and ensure your Prius stays in top condition.

Frequently Asked Questions

How do you jump start a Prius?

On any 2004-2015 Prius, connect the positive (red) jumper clamp to the jump-start terminal in the engine-bay fuse box (under a red cover marked +), connect the negative (black) clamp to unpainted metal on the engine, and hook the other ends to a donor vehicle or jump pack. Wait about 5 minutes, then press the Power button with your foot on the brake until “READY” appears. Disconnect the cables in reverse order, negative off the Prius first. You never connect directly to the 12-volt battery in the rear cargo area. On a 2016–2022 (Gen 4) Prius the 12-volt battery is under the hood, so you connect right at the battery — see the Gen 4 section above.

How do you jump start a 2010 Prius?

The 2010-2015 Prius jump starts almost exactly like the earlier cars. The 12-volt battery is at the right rear of the cargo area, but you never need to reach it: open the hood, open the black cover on the driver-side fuse box, and flip up the red cover over the jump-start terminal. Connect positive there, negative to bare metal on the engine, charge for about 5 minutes from a donor car or jump pack, then press the brake and the Power button until you see “READY.” Be extra careful with polarity — reversed cables on these cars blow the main fuse and can damage the DC/DC converter.

Where is the 12V battery in a 2017 Prius?

Under the hood on the driver’s side, near the base of the windshield next to the fuse box, with a red cover over the positive terminal. That’s true for all 2016–2022 Prius models, including the Prius Prime. On 2004–2015 models it’s in the right rear of the cargo area instead.

Can you jump start a Prius from another car?

Yes. Any vehicle with a working 12-volt system — or a portable jump pack — can jump start a Prius, because it is the small 12V auxiliary battery that needs the boost, not the high-voltage hybrid battery. The Prius doesn’t crank a starter motor, so it only needs a modest amount of current; a small jump pack is plenty.

Can a Prius jump start another car?

We don’t recommend it. A Prius has no alternator — its 12-volt system is fed by a DC/DC converter that was never designed to supply the huge current a conventional starter motor draws, and the small auxiliary battery doesn’t have the cranking amps either. Trying to jump start a regular gas car from your Prius risks damaging the converter and other 12-volt electronics. Use a jump pack or another conventional vehicle instead.

How long should a Prius run after a jump start?

Leave it in READY for 30 to 60 minutes, outdoors or with the garage door fully open — the gas engine will start on its own while it charges. Parked is fine, since the car charges its 12V battery whether it’s moving or not. If the battery was completely flat, give it a few hours or put it on a proper charger, and have it tested.

Why does my Prius 12V battery keep dying?

The most common reason is simple age. There’s no set replacement interval — how long a 12V lasts depends on use, climate, and how often the car sits — so regular testing beats the calendar. That’s why we check your 12V at every intermediate service: you don’t have to think about it, because we already are. Parasitic drains like a light left on or a door ajar will also discharge it, and so will sitting in IG-ON mode without the hybrid system running, since the 12-volt battery only charges when the car is in “READY” mode. If the battery keeps dying even after a full charge, have it tested — it may need professional diagnosis and replacement.

Questions about your car? Text us at 503-969-3134 — it’s the fastest way to reach us.

About the author: Travis Decker is the owner of Atomic Auto in Portland, Oregon, and an ASE Master Technician (L1, L3). Atomic Auto specializes in Toyota, hybrid, and EV service.

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