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Getting the Most from Your Jump Starter


Editor’s Note: We are updating the most popular article among all the articles we have published on this blog. It is also one of the most useful article we have ever published. This time of year, we have many, many new newsletter recipients who have entered our world through the purchase of a new jump starter. Many of them are first time jump starter purchasers and these tips can help any owner of new jump starter, whether it is your first one or tenth one.

Your jump starter, whether it contains a lead acid AGM battery or a lithium ion battery, is a perishable product. From the first time a battery is charged, it is constantly undergoing microscopic chemical changes, all of which march it toward its demise. But, that march can be very slow or very fast, largely depending on how you treat it (and the overall unit). Keeping the below steps in mind could extend the life of your jump starter as much as 2-3 times longer than if they are not followed.

1. Keep your jump starter charged

Avoid situations that result in the unit sitting in a discharged state for long periods. Lead acid jump starter batteries have no memory issues and cannot be harmed by frequent charges, even when only slightly discharged. Even lithium batteries are always better served by frequent charging than infrequent charging. The best practice is to charge a jump starter after each use. Even in those cases where this type of charge frequency is unrealistic, nightly charging should be done if the unit is used frequently. In those cases where the jump starter is not regularly used, charge it every 3 months to ensure that the battery is not sitting in a discharge state for extended periods, no matter what type of battery is inside. In periods of extreme cold, where the jump starter is left in a vehicle parked outdoors overnight, charging once per month is recommended.

2. Respect the duty cyle of your jump starter

Every jump starter is subject to a duty cycle in which the vehicle can be cranked for a short amount of time and then requires a period of rest – see your operator’s manual for the specific details of your jump starter. For almost all Clore Automotive jump starters, the recommended duty cycle is 6 seconds of cranking followed by 3 minutes of rest. This will avoid excessive heat build-up within the jump starter battery, which can damage its internal construction and reduce its useful life. In the case of lithium jump starters, this required rest is built into the software (for Clore products) to make it easy to avoid damaging the unit.

3. Store at a moderate Temperature

Whenever possible, store your jump starter in a moderate temperature environment, between 50˚F and 70˚F (10˚-20˚C). Like vehicle batteries, exposure to extreme temperatures is detrimental to jump starter batteries, both in the short term and long term. For instance, a jump starter stored at 20˚F will have less jump starting power for a needed jump start than one stored at 60˚F. We realize that, in many parts of North America and the world, storing your jump starter in a vehicle means storing it in temperatures well below 50˚F. We get calls on this all the time. In these cases, your jump starter should serve you just fine. Please see our note in number 1 above regarding charging frequency in extreme cold spells. Also, if your low is going to be -30˚F overnight and you have a critical event the next morning, it is probably a good idea to bring your jump starter in for the night (better safe than sorry).

4. Disconnect

When you have completed a successful jump start, it is important to disconnect the jump starter from the now running vehicle as quickly as possible, always remembering to follow all safety procedures and the proper disconnection sequence. Typical vehicle alternator output is much higher than the recommended recharge rate for any jump starter battery. Charging a battery (any battery) at a rate greater than the recommended charge rate is detrimental to its long term health. Many technicians leave the jump starter connected after a successful start, thinking that it is a fast and easy way to get the unit recharged, but this practice should be avoided. For lithium units, again, this protection is usually built-in (it is on our models), such that once the jump started verifies the vehicle has started, it will (internally) disconnect itself from the vehicle to avoid overcharging.

5. Safety

Following all recommended safety procedures is not only best for your personal safety and the well being of your vehicle, it is also best for long jump starter life. We know it’s a hassle to find a proper engine or chassis ground to which to connect the negative jump starter lead. But, it is way safer to make the effort, plus it reduces potential damage to your jump starter. Other safety steps also reduce the likelihood of putting the jump starter in a compromising situation. Even if your jump starter (and vehicle) survives a reverse polarity near miss, it can take a toll on the battery’s state of health and reduce its lifespan. Take your time. Do it right – your jump starter will be glad you did.

6. Maintenance

Until now, our focus has been on the battery, which is the heart of a jump starter and the most critical component impacting its durability and service life. That said, other factors should be kept in mind. Remember that many of the batteries your jump starter comes into contact with are in poor condition, which can result in battery acid and corrosion on or around the posts. After jump starting a vehicle with a battery in such a condition, wipe down your clamps (particularly the positive, which is the only clamp that should contact the battery) with a clean cloth to remove any residual battery acid. For clamps that have a high level of acid contact, a mixture of baking soda and water can be used with a wire brush.


Following these simple steps can greatly extend the life of your jump starter and also help to ensure that your jump starter is ready for service each time you need it.

26 Responses

  1. My Jump & Carry is a few years old. Can it be load tested to see if it has the ability to jump off another vehicle? It does not seem to be as good as it once was.

    1. Chris – Thanks for your question. Yes. We recommend using a traditional 100A fixed load tester, hooked to the clamps and loading the unit for 10 seconds. If the battery, at the end of 10 seconds, has 9.5V or more, it is good. Recharge the unit and you should be good to go. If below 9.5V, suspect that the battery is compromised. Thanks, Jim from Clore Automotive

  2. All good tips, so thanks.
    My JNC660 has never, ever failed me. After a couple of bad experiences with other jumpers, I’m very happy I bought this one.

    1. Rob – Glad you found it useful. Also, we are very glad to hear that your JNC660 is performing well for you. Thank you, Jim from Clore Automotive

  3. I’d like to sign up for the Quarterly Reminders to charge, but there was no link there (in the ad) to do that.

  4. Replacement batteries are not a realistic option. A new JNC660 costs about $145.00 on some retailer sites and the replacement battery is about $126.00. The cost difference between the two is minimal and makes me wonder why. Clore Automotive should be able to provide a more reasonable cost solution for battery replacements for their loyal customers and the environment.

    1. Stan – You make a good point. Unfortunately, the units themselves are usually discounted by our resellers, but replacement parts, such as batteries, are typically not discounted in the channel. This leads to some pricing anamalies, such as you have pointed out with the batteries. We are working to corrent this. Thank you, Jim from Clore Automotive

      1. I agree with Stan. The majority of the cost is the battery. Some of us like to keep stuff out of landfills, and if simply replacing the battery in the unit brings it back to real life, than why not. But again, considering the cost of the battery alone, it a hard choice to not just buy another unit. Maybe the could offer a discounted rate to people who have purchased and registered their jumpers new. This way, people would be more likely to repair rather than replace. On the other hand, I assume it would cut into your profits of new units. I know in the past, people have offered me their “no good” jumpers that were in excellent visual condition (probably because they were never used). But after pricing out a new battery, it wasn’t worth it. Sometimes a replacement battery was more than a new unit. I’m actually in the process of replacing my 2 year old NOCO GB70 with a JNC345. I wasn’t even aware, Clore made Small jumpers. When i found out, I knew it was a brand that has longevity on its side. I need a jumper that’s gonna work when I need it to, and last (provided I take care of it). I use them for my small auto repair business. They’re never left outside and always recharged after using.

        1. Chris – First, you are totally correct. Battery pricing has been a problem for a long time and we need to fins a way to correct it. They will never be cheap – the battery is typically 70% of the cost of the build – but they could and should be reasonable. Again, we are working on it. We are glad to hear about the JNC345. It is a great unit and will serve you well. We thank you for your continued support. Thanks, Jim from Clore Automotive

      2. You can find replcement batteries on Amazon for around 55.00. That’s what I paid a year ago for my JNC-660’s battery.

        1. Gary – Thanks for your comment. It is true that there are a lot of batteries available from many different sources. Some are pretty good, some less so. We always recommend doing your homework, but it can sometimes work out great. Thanks again, Jim from Clore Automotive

    1. Donna – Thanks for your comment. We are glad that the timing we good for you. Wishing you the best. Thanks, Jim from Clore Automotive

  5. Folks need to know that the positive cable should be installed on the positive post first when jump starting a vech and the negative cable should be disconnected first when the vehc has started.

    1. Roger – Thanks for your comment. Yes, you are correct. Positive first to the positive battery post, then negative to engine or chassis ground. Reverse the sequence when disconnecting. Great point and it can’t be stated too many times. Thanks, Jim from Clore Automotive

  6. Excellent concise information condensed into a ‘short’ article ! Small enough to print out and keep in the ‘Glovebox’, which is what will do for the JNC660 have now had for Years…. Saved many a AAA Call
    in the quite rural area that currently live in.
    Having the 660 ‘Onboard’ has provided the opportunity to help other drivers especially now, during
    the pandemic, with the cost of keeping older vehicles in good running condition more expensive…
    Frequently those you help out easily notice the Iconic Blue 660 and ask about it… It’s one of the few
    automotive items can recommend to others without reservation, re its handy size yet built like a Tank
    with enough power and reserve to support cars of today having OEM batteries large enough to keep
    their all too numerous ‘current Hungry’ ECU’s Happy when they age…
    It’s how personally found Clore Automotive in the first place via a large local towing outfit during a freak snow ‘dump’ in March close to one of the Great Lakes. They used a Clore JNC of slightly smaller
    Capacity whose professional and robust build made a lasting impact on the mind ! Even the thick, Heavy gauge conductors are nice and supple during below freezing temperatures !

    1. Gary – Thanks for your comments. We really appreciate it and are glad that your JNC660 has served you so well. Thanks again, Jim from Clore Automotive

  7. I have a JNC 660 that got A LOT OF USE until April 2016 when I retired. I have used it a few times since then. I also have a JNC 4000 (red box) that also gets limited use and I replaced the battery in that one with the same type battery as the 660.
    The 660 has a GREAT on board charging system. The 4000……not so good. So I connected the two together, positive to positive, negative to negative and used the 660’s charging system for both. It worked! If this is not a good idea, I’ve had the 660 apart and can adapt a 660 charger to the 4000. Thar 660 charger does a great job for the 660. I once had the charger plugged in to A/C power, the 660’s cables were attached to a vehicle’s fully charged battery and used that clean power to program a Powertrain Control Module (PCM). Where I worked, we didn’t have a “clean” charging supply, so I improvised. The 2 batteries
    voltage did go down slowly, but the programming went well and all was well in Ford land after the programming.
    Hope this helps others out there.

    1. Mike – Thanks for your feedback. We are glad that you are happy with your JNC660. In terms of the charger/charging system, it is essentially the same from the JNC4000 to the JNC660. I suggest that you call our Tech line at 800 328 2921, option #2, to see if they can help troubleshoot the issues you have seen with your JNC4000 charging system. Thanks again, Jim from Clore Automotive

  8. Hello:
    I have a 2005 Chevy Impala, 3.8 engine. Where can I safety attach the black cable to the car chassis. I have a JNC 660.
    Thank you.

    1. Tim – Thanks for your question. In all honesty, it is different for each vehicle. With the shrouding that has been added to engine compartments since around the year 2000, this has gotten more difficult. But, it is worth the time and effort to find a proper gorund on each vehicle you jump start, even if it means having to remove a piece of shrouding during the start. We would suggest checking the forums if you haven’t been able to find a good ground as of yet. Thanks, Jim from Clore Automotive

  9. Johara,
    After years of owning vehicles with a cast iron engine block, I made the mistake of connecting the negative jumper clamp to a solid part of an aluminum engine block. Big mistake, causing a cloud of white smoke from burning aluminum. Since then, I have been connecting the negative clamp to the negative battery post. Batteries nowadays are sealed, so you don’t have to loosen any caps and put a rag over the battery to absorb acid explosions.

    1. Dan – Thanks for your comment. Honestly, we hadn’t really taken the aluminum engine block into consideration. For vehicles with those engines, we highly recommend making the negative connection to a good chassis ground. While you are correct about the design of modern batteries being different, all lead acid batteries, even newer ones, will outgas hydrogen during normal charging and cranking. This is why we stronly discourage making that second connection at the battery. Thanks again, Jim from Clore Automotive

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