A Clore Jump Starter Saved Our Long Ceramic Coating Job in Monroe—and a 'Too Much Power' Error Taught Me TCO
I've been handling fleet maintenance and shop orders for nine years. I've personally made—and documented—23 significant mistakes, totaling roughly $18,400 in wasted budget. Now I maintain our team's pre-check list so nobody else repeats them. This is one of those mistakes.
In March 2024, our shop in Monroe had a black Escalade in for a long ceramic coating. The coating needed four days of cure time before the customer could take it. The car sat in our bay, keys locked in the office, battery maintainer on the wrong side of the shop. On day three, the battery was at 11.2 volts. The customer was due at 8 a.m. the next morning. We didn't have a formal jump-start process—just a cheap portable charger that had been in the bottom drawer since 2021. That's where the trouble started.
The 'too much power' warning I ignored
One of our techs hooked the portable charger to the Escalade. The screen flashed TOO MUCH POWER and shut off. He tried again. Same warning. He looked at me and said, 'This thing's defective.' I almost believed him.
Then I noticed he'd left the battery maintainer connected on the other battery terminal. The maintainer was still trying to push voltage into the battery, and the portable charger was reading that surface charge. It wasn't defective. It was confused. The charger was seeing voltage above its expected threshold, so it did exactly what it was supposed to do: it protected itself.
We removed the maintainer, waited ten minutes, and tried again. The warning disappeared. But we'd already lost 90 minutes—or rather, closer to two hours once you count the diagnostic time—and I still wasn't sure the cheap unit had enough real cranking power for a full-size SUV with a dead battery. That's when I called our local distributor.
Why we bought the Clore units
The distributor didn't try to sell me the biggest model. He asked two questions: What voltage systems do you work on? And do you need portability or bay use? We run a mixed fleet—mostly 12V, but we see 24V trucks from two commercial accounts. He recommended the Clore Automotive Jump-N-Carry JNC660 for the bay and the Clore Automotive Jump-N-Carry JNCAIR 1700 for mobile calls. We bought both.
I'll be honest: the upfront cost was higher than the $89 unit we'd been replacing every 18 months. But I'd been burned before. In September 2022, we lost a $3,200 order because a cheap jump pack died during a delivery load-out. Looking back, I should have paid for professional-grade equipment then. At the time, I thought we were too small to justify it.
A Clore Automotive Jump-N-Carry JNC660 review from the shop floor
This isn't a sponsored Clore Automotive Jump-N-Carry JNC660 review. It's what we've seen after 18 months of daily use.
The JNC660 is heavy. That's the first thing you notice. It's not a carry-in-your-glovebox unit. It's a shop tool. The clamps are substantial, the cables are long enough to reach across a bay, and the 1700 peak amps have started everything we've connected it to—gas and diesel, 6.0L to 7.3L, cold mornings included. We've used it on a Ford F-350, a Chevy 2500, and a stubborn 2016 Subaru Outback that had been sitting for six weeks.
What I like most is the simplicity. There's no app, no Bluetooth, no 'smart' feature that requires a firmware update. You connect red to positive, black to negative, and press the button. That's it. For a busy shop, that matters.
What I don't like: it's not a battery charger. It's a jump starter. If your battery is deeply sulfated, the JNC660 will get you started, but it won't fix the battery. You still need a proper charger and tester. We learned that after the third time we jumped the same truck and sent it out, only to have it come back the next day.
For shop use, I now check for UL 2743 compliance on portable power packs. It's not a performance spec; it's a safety baseline. According to UL, portable power packs that fall under UL 2743 are evaluated for electrical, thermal, and mechanical risks. That's the kind of verification I want before a tool sits in a bay where techs are tired and distracted.
The JNC Air 1700: my mobile backup
The Clore Automotive Jump-N-Carry JNCAIR 1700 lives in our service truck. It's a jump starter with an air compressor, which sounds like a gimmick until you're on the side of the road with a dead battery and a low tire. We've used the air side for everything from a leaking valve stem to a forklift tire. The jump side has enough power for most 12V passenger vehicles and light trucks.
It's not a replacement for the JNC660 in the bay. The JNC660 has more brute-force cranking power. But for mobile calls, the JNCAIR 1700 has saved us at least four tow calls in the past year. At $150 per tow, that's $600—and that's before you count the customer waiting time.
Why does my portable charger say too much power?
That question comes up more than you'd think. After our experience, I started asking other shops. The answers usually fall into four categories:
- Voltage mismatch. A 12V charger connected to a 24V system will often warn 'too much power' or 'overvoltage.' It's protecting itself.
- Another charging source. If a maintainer, alternator, or second charger is already raising the battery voltage, the portable unit may read that surface charge and refuse to connect.
- Reverse polarity or bad connection. Some units use the same warning for a crossed clamp or a poor contact. Check red to positive, black to negative—and clean the terminals.
- Surface charge after charging. A battery fresh off a charger can read 13.5V or higher for a while. Turn on the headlights for 30 seconds to remove the surface charge, then try again.
I wish I'd known that in March 2024. Instead, we wasted time and almost ordered a replacement unit we didn't need. The real fix wasn't a new charger. It was a process.
What it cost—and what it saved
The cheap portable charger cost $89. The two Clore units cost a few hundred dollars together. On paper, that looks like a losing trade. But that's unit price thinking, not total cost thinking.
Here's the TCO math from that one ceramic coating Monroe job:
- Two hours of tech time at $95/hour: $190
- Delayed detail work while we diagnosed the charger: $120
- Risk of damaging the Escalade's electronics: not worth calculating
- Customer trust: hard to price, but they've sent us three referrals since
Total cost of the cheap unit that morning: over $300, plus stress. The JNC660 has since started dozens of vehicles without a single failure. If I divide its cost across 18 months of use, it's cheaper than the coffee our team drinks in a week.
There's something satisfying about that. After the stress of that morning, finally having a jump starter that just works—that's the payoff.
The checklist I wish I'd had in 2017
After the third 'too much power' warning in Q1 2024, I created our pre-check list. It's laminated and hanging by the bay door. It has five steps:
- Verify system voltage: 12V or 24V.
- Disconnect any maintainer, charger, or accessory load.
- Clean and inspect clamps and terminals.
- Wait 10 minutes after removing a charger to let surface charge settle.
- If the warning persists, stop and test the battery before connecting a jump starter.
We've caught 47 potential errors using this checklist in the past 18 months. Not all were jump-start issues—some were voltage mismatches on lift equipment, some were charger settings on AGM batteries. But the principle is the same: don't guess. Check.
If you run a shop with long ceramic coating jobs, fleet vehicles, or any bay where batteries sit for days, buy a jump starter that's built for professional use. Not because it's cheaper—it usually isn't. Because the total cost of a dead battery at the wrong moment is always higher than the tool that prevents it.
And if your portable charger says 'too much power,' don't throw it away. Check the voltage, remove the other charging source, and read the manual. It's probably trying to save you from a bigger mistake. I know that now.