Lithium vs Lead-Acid Jump Starters: Which Is Better?
This draws on NOCO’s GB40 data sheet and user guide, Clore’s JNC660 product page and manual, and Battery University’s BU-502; see how we research.
The two examples side by side
| Spec | NOCO GB40 (lithium) | Clore JNC660 (lead-acid) |
|---|---|---|
| Battery | 24 Wh lithium-ion | Sealed lead-acid (Clore PROFORMER) |
| Weight | 2.4 lb (1.1 kg) with clamps; unit alone 1.65 lb (0.7 kg) | 18 lb (8.2 kg) |
| Cables | Clamp set drawn at 23 in (58 cm) on the data sheet | 46 in (117 cm), #2 AWG welding cable |
| Peak / cranking amps | 1000A / Not listed | 1700A / 425A |
| How it charges | USB (5V, 2.1A); about 3 hours on a 2A source | Built-in automatic AC charger (household extension cord needed) or 12V cord |
| Extras | USB output, 100-lumen light; its 12V OUT port is for the clamps only | 12V accessory outlet up to 12A, battery status gauge |
“Not listed” means NOCO’s GB40 documents don’t give it. Both units carry a 1-year limited warranty. For charging details, see how long the GB40 takes to charge.
Weight and cable reach
Weight is the biggest difference. The GB40 measures 6.7 x 3.2 x 1.7 in (17 x 8.1 x 4.3 cm) per its user guide and weighs 2.4 lb (1.1 kg) with clamps. Clore lists the JNC660 at 18 lb (8.2 kg).
Dividing 18 by 2.4 makes the lead-acid unit 7.5 times heavier, so the JNC660 is not a glove-box item.
The weight buys longer, heavier cables. Clore lists 46 in (117 cm) #2 AWG welding cable for the JNC660, while NOCO’s data sheet draws the GB40’s clamp set at 23 in (58 cm), half that length. Longer leads can reach a car parked in a tight spot.
Is lead-acid more powerful?
The ratings can’t tell you, because the two brands rate power differently. Clore lists 1700 peak and 425 cranking amps for the JNC660 but no engine-size rating. NOCO lists 1000 peak amps for the GB40, plus engine limits: gas up to 6.0L and diesel up to 3.0L.
Peak amps is the highest burst a maker claims; cranking amps is current held through a set test (what peak and cranking amps mean). Compare each unit with your own engine, not the other brand’s numbers.
Clore’s manual says the JNC660’s main job is giving a weak battery an extra boost, though it can start vehicles with no other battery present. Even retry rules differ, as how to use a jump starter safely explains: Clore says to let the unit cool 3 minutes if the vehicle doesn’t start within 6 seconds, and NOCO says to wait 20-30 seconds between tries, with at most 5 attempts in 15 minutes, then a 15-minute rest.
Upkeep differs
The lithium example is built to be charged and then unplugged. NOCO says charging the GB40 for more than a week at a time may shorten battery life.
The lead-acid example is built to live on a charger: Clore says the JNC660 can stay on its automatic AC charger indefinitely, since it only uses power as needed to maintain the battery. Off the charger, it needs recharging on Clore’s schedule, which how long a jump starter holds a charge lays out.
Its sealed, non-spillable battery can be stored in any position, and Clore says it can be replaced through Clore Technical Service. For which habit suits you, read should you keep a jump starter plugged in.
Who should buy which
- Commuters and everyday drivers: lithium, like the GB40: light, small and charged over USB.
- Mechanics, shops, dealerships and fleets: lead-acid, like the JNC660, for its long #2 AWG cables, life on a charger and replaceable battery. NOCO’s guide says the GB40 is not intended for a commercial repair facility.
- A cold car and no garage: either type, kept warm. Battery University says a battery giving full capacity at 80°F (27°C) delivers only about half at 0°F (-18°C); see can you leave a jump starter in your car.
- You also want to charge your phone: lithium. The GB40 has a USB output, while the JNC660 lists none and its 12V outlet runs 12V-plug accessories.
The GB40 suits drivers who want a pack that rides in the car, with USB charging and up to 4 phone recharges per NOCO; for bigger engines, see NOCO GB40 vs GB70.
NOCO Boost Plus GB40
A compact 12V lithium jump starter. NOCO rates it at 1000A peak, for gas engines up to 6.0L (366 cu in) and diesel engines up to 3.0L.
Key specs
- 1000A peak
- Gas engines up to 6.0L, diesel up to 3.0L
- Compact 12V lithium
Paid link
View on Amazon (opens in a new tab)The JNC660 suits a garage or shop: in a car’s live 12V outlet, it saves radio, alarm and computer memory while the battery is out, and its own outlet runs accessories up to 12A.
Clore Jump-N-Carry JNC660
A heavy-duty 12V lead-acid jump starter from Clore: 1700 peak amps and 425 cranking amps, with 46-inch (117 cm) cables.
Key specs
- 1700 peak amps, 425 cranking amps
- 46 in (117 cm) cables
- 12V lead-acid
Paid link
View on Amazon (opens in a new tab)Next, check how many amps your engine needs before you choose.
