Should You Keep a Jump Starter Plugged In?
4 lessons in this series, 11 min in total
- How Long Does a Jump Starter Hold a Charge? 3 min read
- Can You Leave a Jump Starter in Your Car? 3 min read
- Should You Keep a Jump Starter Plugged In? 2 min read
- Do Jump Starters Work in Cold Weather? 3 min read
This comparison draws on NOCO’s GB40 and GB70 guides and GB40 data sheet, plus Clore’s JNC660 manual, product page and blog. How we research explains the method.
Charging rules side by side
| Rule | NOCO GB40 | NOCO GB70 | Clore JNC660 |
|---|---|---|---|
| Internal battery | Lithium-ion | Lithium-ion | Sealed lead-acid |
| Recharge when unused | Not stated | Not stated | Every 3 months |
| After each use | Not stated | Not stated | Recharge immediately |
| Leaving it on the charger | Avoid more than a week at a time | Avoid more than a week at a time | Indefinitely on the AC charger |
| Recharge time | 3 h on 2A USB | 7 h on 2A USB; 2-3 h via 12V input | Not listed |
| Charge indicator | Four LEDs: 25/50/75/100% | Four LEDs: 25/50/75/100% | Gauge: green, yellow, red |
The NOCO times are explained in how long the GB40 and GB70 take to charge.
NOCO GB40 and GB70: charge, then unplug
Both NOCO guides say an unused unit discharges over time and must be recharged before use. It needs a top-up now and then, not a constant connection.
NOCO warns that charging for more than a week at a time may shorten battery life, and says to disconnect the unit when it’s not in use. In practice: plug it in, wait for the 100% LED, unplug it. Leaving it on a charger for weeks is the habit to avoid.
The GB40 data sheet adds that the error LED blinks when the internal battery is too hot or too cold, so charge it indoors.
Clore JNC660: leave it on the AC charger
Clore’s manual calls the AC charger fully automatic, safe to leave connected indefinitely. On its blog, Clore told owners that monthly charging is excellent and every 90 days or so is fine.
The 12V cord is different: watch that charge closely, because overcharging will damage the unit. Clore also says not to recharge it clamped to a running car, since the alternator can overcharge it, or with a regular 10-amp battery charger.
The box weighs 18 lb (8.2 kg), per Clore’s product page; the manual says it can be stored in any position and used in rain, snow, heat or cold. One blog commenter’s mechanic has had a Jump-N-Carry since the 1990s and replaced its battery twice.
Which one fits how you store it
- A small pack you check a few times a year: the GB40, or the GB70 for bigger engines (NOCO GB40 vs GB70), since it needs a charger only now and then.
- A garage outlet and an always-full unit: the JNC660, the only one of the three made to stay connected.
- A very hot or freezing car: read can you leave a jump starter in your car, since a parked car can pass both makers’ limits.
The GB40 suits drivers who want the smallest pack and don’t mind unplugging it.
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 where it can stay plugged in and its weight doesn’t matter.
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)Check your manual’s charger rule before leaving anything plugged in, and use how long a jump starter holds a charge for the recharge schedule.
