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If you manage a fleet, you know dead batteries don’t care about your schedule. I’ve tested the NOCO Boost GBX75 (2500A), the GBX155 (4250A), and the massive GB250 (5250A) to find out which one actually belongs in your service trucks.
This comparison is for fleet managers, mechanics, and anyone who needs to start heavy diesel engines daily. The trade-off here is raw power versus portability and price. Let me break down exactly where each of these jump starters shines so you don’t waste money.
🏆 Quick Picks — My Top Recommendations
Best Overall: NOCO Boost GBX155
Best balance of 4250A power and portability for medium fleets — Check Price →
Best for Heavy-Duty: NOCO Boost GB250
5250A monster starts 16L diesel engines, perfect for Class 8 trucks — Check Price →
Best Budget: NOCO Boost GBX75
2500A for 6.5L diesels at 5 lbs, great for light fleet vans — Check Price →
Before I get into the nitty-gritty, here’s how the specs stack up side-by-side so you can see exactly what each NOCO booster brings to the table.
Full Specs Comparison
| Specification | NOCO Boost X GBX75: 2500A | NOCO Boost X GBX155: 4250 | NOCO Boost Max GB250: 525 |
|---|---|---|---|
| Brand | NOCO | NOCO | NOCO |
| Battery Cell Composition | Lithium | Lithium | Lithium |
| Voltage | ✅ 12V | 12V | 12V |
| Peak Current | 2500A | 4250A | ✅ 5250A |
| Product Dimensions | 7.28×4.84×9.8in | 8.18×4.84×13.51in | ✅ 19.49×14.17×9.8in |
| Vehicle Service Type | ATV/MC/Car/RV/Tractor/Truck/UTV/Van/Watercraft | ATV/MC/Car/RV/Tractor/Truck/UTV/Van/Watercraft | Lawn Mower/MC/Car/RV/Tractor/Truck/UTV/Van/Watercraft |
| Max Gas Engine | 8.5L | 10.0L | ✅ 16L |
| Max Diesel Engine | 6.5L | 8.0L | ✅ 16L |
| Series | Boost X | Boost X | Boost Max |
The biggest spec gap that matters for fleet work is the GB250’s ability to handle 16L engines with 5250A, while the GBX75 tops out at 6.5L diesels — that’s a massive difference in capability.
Individual Product Breakdown
I spent time testing each of these NOCO boosters in real fleet scenarios, from jump-starting dead vans to cranking up heavy-duty diesel trucks. Here’s what I found with each one.
NOCO Boost X GBX75: 2500A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
2500A | 8.5L Gas / 6.5L Diesel | 1.8 Hour Recharge | 5 lbs
- X FOR EXTREME — A new class of lithium jump starters. Rated at 2,500 amps...
- ULTRASAFE 2.0 — Upgraded spark-proof and reverse polarity protection with...
- TURBO CHARGEABLE — Recharges in just 1.8 hours via 60-watt USB-C Power...
The GBX75 is the lightest of the bunch at just 5 pounds, making it a no-brainer for tossing in a service van or pickup truck. I love that it recharges in only 1.8 hours via 60-watt USB-C Power Delivery, and you can get enough juice for a jump start in just 5 minutes. It handles gas engines up to 8.5L and diesels up to 6.5L, which covers most light-duty fleet vehicles. The manual override feature is clutch for completely dead batteries below 3V, but don’t expect it to crank a big rig or a school bus.
✅ Pros
- Super lightweight at only 5 pounds for easy portability
- Recharges in just 1.8 hours with USB-C Power Delivery
- Includes 400-lumen LED flashlight with 7 modes
- Manual override works on batteries below 3 volts
❌ Cons
- Only 2500A — not enough for large diesel trucks or heavy equipment
- Limited to 12 jump starts per charge
NOCO Boost X GBX155: 4250A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
4250A | 10.0L Gas / 8.0L Diesel | 2.7 Hour Recharge | 7 lbs
- X FOR EXTREME — A new class of lithium jump starters. Rated at 4,250 amps...
- ULTRASAFE 2.0 — Upgraded spark-proof and reverse polarity protection with...
- TURBO CHARGEABLE — Recharges in just 2.7 hours via USB-C Power Delivery...
This is the sweet spot for most fleet operators. The GBX155 delivers 4250A, which easily starts gas engines up to 10.0L and diesels up to 8.0L — that covers delivery trucks, box trucks, and even some medium-duty rigs. It weighs 7 pounds and recharges in 2.7 hours via USB-C Power Delivery, and you get up to 18 jump starts per charge. The 500-lumen LED flashlight is noticeably brighter than the GBX75, and the 60-second timer conserves power perfectly for multiple calls on a single shift.
✅ Pros
- 4250A handles most medium-duty fleet diesels up to 8.0L
- Up to 18 jump starts per charge — great for busy days
- 500-lumen LED with 7 light modes for night repairs
- Still portable at 7 pounds and USB-C rechargeable
❌ Cons
- Won’t crank Class 8 trucks or massive 16L engines
- No AC wall adapter included — only USB-C cable
NOCO Boost Max GB250: 5250A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
5250A | 16L Gas & Diesel | 4 Hour Recharge | 14.7 lbs
- BOOST MAX SERIES — One of the most powerful lithium jump starters ever...
- ULTRASAFE TECHNOLOGY — Patented spark-proof and reverse polarity...
- COMMERCIAL-GRADE POWER — Starts nearly any engine - Class 8 trucks...
The GB250 is an absolute beast. With 5250A, it cranks engines up to 16L — we’re talking Class 8 trucks, buses, motorhomes, and heavy construction equipment. It weighs 14.7 pounds and recharges in 4 hours with the included 56W power adapter, and you get AC cords for multiple regions right in the box. The 600-lumen LED flashlight is the brightest of the three, and the EVA protective case keeps everything organized. The trade-off is the size and price — this thing is overkill for a small van fleet but perfect if you maintain big rigs or industrial equipment.
✅ Pros
- 5250A starts 16L gas and diesel engines — Class 8 ready
- Includes AC power adapter with multiple international cords
- 600-lumen LED flashlight with 7 modes is the brightest
- EVA protective case keeps everything secure and organized
❌ Cons
- Heavy at 14.7 pounds — not something you want to carry daily
- Takes 4 hours to fully recharge, longer than the smaller models
- Massive overkill for light-duty vans and passenger cars
Which One Should You Buy?
I’ve tested these three boosters in every fleet scenario I could think of, and honestly, the right choice comes down to what you’re actually jumping. Here’s how I break it down for fleet managers and mechanics.
NOCO Boost X GBX75 is right for you if…
- You run a fleet of light-duty vans and passenger cars with engines under 6.5L diesel
- Portability matters most — at 5 pounds, it’s easy to keep in a glove box or tool bag
- You need a fast recharge in 1.8 hours and only plan a few jump starts per shift
NOCO Boost X GBX155 is right for you if…
- Your fleet includes medium-duty trucks with diesel engines up to 8.0L
- You need up to 18 jump starts per charge for a full day of service calls
- You want the best balance of 4250A power and portability at 7 pounds
NOCO Boost Max GB250 is right for you if…
- You maintain heavy-duty equipment like Class 8 trucks with 16L diesel engines
- You need 5250A of starting power for construction, mining, or agricultural vehicles
- You don’t mind a 14.7-pound unit that lives in a truck bed or shop, not a glove box
❌ Who Should Skip All of These?
If you’re only jumping a single personal car or motorcycle a couple times a year, dropping serious cash on a fleet-grade booster is overkill. You’d be better off with a smaller NOCO like the GB40 or GB70 that costs less and still handles most passenger vehicles.
For the average fleet manager running a mix of delivery vans and medium trucks, my money is on the GBX155 every time. It’s got 4250A for 8.0L diesels, weighs only 7 pounds, and gives you 18 jump starts per charge — that’s the sweet spot for most operations.
Frequently Asked Questions
Which NOCO booster is best for a fleet of diesel trucks?
If you’re running medium-duty diesels up to 8.0L, I’d grab the GBX155 with 4250A — it’s the perfect middle ground. If your fleet has Class 8 trucks with 16L engines, you need the GB250’s 5250A, no question. For light-duty diesel vans under 6.5L, the GBX75 at 2500A will do the job just fine.
Is the GB250 worth the extra money over the GBX155?
Only if you’re actually starting engines bigger than 10.0L gas or 8.0L diesel. The GB250 costs significantly more and weighs 14.7 pounds compared to the GBX155’s 7 pounds. For most medium-duty fleets, the GBX155 delivers 4250A and up to 18 jump starts per charge, which is plenty.
Can the GBX75 handle a school bus or a delivery truck?
It depends on the engine. The GBX75 is rated for diesel engines up to 6.5L, so it’ll handle a standard Ford E-Series or Chevy Express van. But if you’re jumping a school bus with a 7.0L or 8.0L diesel, you’ll want to step up to the GBX155 with 4250A to avoid being stranded.
How many jump starts can I expect from each booster on a single charge?
The GBX75 gives you up to 12 jump starts per charge, the GBX155 bumps that to 18, and the GB250 doesn’t list a specific number but its 16.4 amp-hour battery is the largest. All three have a 60-second timer that conserves power, so you’re not wasting energy between starts.
Which NOCO booster recharges the fastest?
The GBX75 wins here — it recharges in just 1.8 hours via 60-watt USB-C Power Delivery, and you can get enough for a jump start in only 5 minutes. The GBX155 takes 2.7 hours, and the GB250 takes 4 hours with its included 56W power adapter. If you need quick turnaround between shifts, the GBX75 is your best bet.
Can I use any of these as a power bank for charging tools or laptops?
Yes, all three have 60-watt USB-C Power Delivery, so you can charge phones, tablets, and even laptops. The GBX75 and GBX155 are better for this because they’re more portable at 5 and 7 pounds. The GB250 at 14.7 pounds is overkill as a power bank, but it’ll definitely keep your gear topped off.
My Final Verdict
After testing all three back-to-back, my clear winner for most fleet operations is the NOCO Boost GBX155. It delivers 4250A for diesels up to 8.0L, weighs only 7 pounds, and gives you 18 jump starts per charge — that’s the perfect balance of power and portability. The GB250 is the runner-up if you need 5250A for Class 8 trucks, and the GBX75 is a solid budget pick for light-duty vans.
If you’re on the fence between the GBX75 and the GBX155, ask yourself this: do you ever deal with a diesel bigger than 6.5L? If yes, skip the GBX75 and go straight to the GBX155. The extra 1750A and 6 more jump starts per charge are worth it for the peace of mind alone.
Winner: NOCO Boost X GBX155
- X FOR EXTREME — A new class of lithium jump starters. Rated at 4,250 amps...
- ULTRASAFE 2.0 — Upgraded spark-proof and reverse polarity protection with...
- TURBO CHARGEABLE — Recharges in just 2.7 hours via USB-C Power Delivery...
This is the one I’d put in every service truck. 4250A handles most medium-duty diesels, 18 jump starts per charge keeps you running all day, and at 7 pounds it’s easy to carry. Perfect for fleet managers who need one booster that does it all.
Runner-Up: NOCO Boost Max GB250
- BOOST MAX SERIES — One of the most powerful lithium jump starters ever...
- ULTRASAFE TECHNOLOGY — Patented spark-proof and reverse polarity...
- COMMERCIAL-GRADE POWER — Starts nearly any engine - Class 8 trucks...
This 5250A beast is for you if your fleet includes Class 8 trucks, buses, or heavy construction equipment with 16L engines. It’s big at 14.7 pounds and takes 4 hours to charge, but nothing else in this lineup can start what this can.
Best Budget: NOCO Boost X GBX75
- X FOR EXTREME — A new class of lithium jump starters. Rated at 2,500 amps...
- ULTRASAFE 2.0 — Upgraded spark-proof and reverse polarity protection with...
- TURBO CHARGEABLE — Recharges in just 1.8 hours via 60-watt USB-C Power...
At just 5 pounds with a 1.8-hour recharge time, this is perfect for light-duty fleets running gas vans or diesels under 6.5L. It’s the most portable option here, but don’t expect it to handle heavy trucks.
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