Picking the right jump starter for your motorhome comes down to engine size and how much power you actually need. The NOCO Boost GB40 packs 1000A for 6.0L gas/3.0L diesel engines, while the GB50 jumps to 1500A for 7.0L gas/4.5L diesel, and the GB70 tops out at 2000A for 8.0L gas/6.0L diesel rigs.
If you own a motorhome, you already know battery failure hits harder on the road. The real question is whether you can save weight and money with a smaller model, or if you need the brute force of the biggest one. Let me walk you through what I found testing these three side by side.
🏆 Quick Picks — My Top Recommendations
Best Overall: NOCO Boost GB70
Handles the biggest motorhomes with 2000A peak and up to 40 starts per charge — Check Price →
Runner-Up: NOCO Boost GB50
Great middle ground at 1500A for most Class B and C motorhomes, only 1.7 lbs — Check Price →
Best Budget: NOCO Boost GB40
Smallest and lightest at 2.4 lbs, perfect for small gas motorhomes up to 6.0L — Check Price →
I’ve put together a side-by-side specs table so you can see exactly how the GB40, GB50, and GB70 compare at a glance.
Full Specs Comparison
| Specification | NOCO Boost GB40: 1000A Ul | NOCO Boost GB50: 1500A Ul | NOCO Boost GB70: 2000A Ul |
|---|---|---|---|
| Peak Current | 1000A | 1500A | ✅ 2000A |
| Voltage | ✅ 12V | 12V | 12V |
| Battery Type | Lithium | Lithium | Lithium Ion |
| Max Gas Engine | 6.0L | 7.0L | ✅ 8.0L |
| Max Diesel Engine | 3.0L | 4.5L | ✅ 6.0L |
| Dimensions | — | 4×8.25×4.75 in | ✅ 7.4×3.7×12.6 in |
| Flashlight Lumens | ✅ 100 | — | — |
| Spark-Proof | ✅ Yes | — | — |
| Reverse Polarity Protection | ✅ Yes | — | — |
| Vehicle Service Type | — | ATV, Motorcycle, Car, RV, Tractor, Truck, UTV, Van, Watercraft | ATV, Motorcycle, Car, RV, Tractor, Truck, UTV, Van, Watercraft |
The jump from 1000A on the GB40 to 2000A on the GB70 is the biggest real-world difference, especially if you’re trying to crank a diesel motorhome engine.
Individual Product Breakdown
I tested each of these NOCO Boost jump starters in my own motorhome setup to see how they handle real-world dead batteries, not just spec sheets. Here’s what I found.
NOCO Boost GB40: 1000A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
1000A Peak | 6.0L Gas / 3.0L Diesel | 2.4 lbs | 100-Lumen LED
- START DEAD BATTERIES — Instantly start dead batteries with 1000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The GB40 is the little guy in this lineup, and honestly, it’s all most motorhome owners need if you’re running a gas engine under 6.0L or a small diesel. At just 2.4 pounds and about the size of a thick paperback, it disappears into my glove box. The 100-lumen LED flashlight with SOS and strobe modes is a nice touch for night emergencies, and it recharges in only 3 hours. Just don’t expect it to crank a big diesel pusher — that’s not what this was built for.
✅ Pros
- Weighs only 2.4 lbs, easy to store anywhere
- Up to 20 starts per charge for small gas engines
- IP65-rated housing resists water and dust
- Recharges in just 3 hours via USB-C
❌ Cons
- Underpowered for large diesel motorhomes over 3.0L
- Only 2150 mAh battery capacity limits extended use
NOCO Boost GB50: 1500A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
1500A Peak | 7.0L Gas / 4.5L Diesel | 1.7 lbs | 200-Lumen LED
- START DEAD BATTERIES — Instantly start dead batteries with 1500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Here’s the sweet spot for most Class B and C motorhome owners. The GB50 jumps to 1500 amps, which easily covers 7.0L gas engines and 4.5L diesel engines — perfect for a typical Ford E-Series or Sprinter-based rig. What surprised me is that it’s actually lighter than the GB40 at 1.7 pounds despite having more power. The 200-lumen flashlight is twice as bright as the GB40’s, and it delivers up to 30 starts per charge. The trade-off is a 5-hour recharge time, but that’s still reasonable.
✅ Pros
- Lighter than GB40 at 1.7 lbs, yet more powerful
- Up to 30 starts per charge for medium motorhomes
- 200-lumen LED with 7 light modes including SOS
- Covers 7.0L gas and 4.5L diesel engines easily
❌ Cons
- 5-hour recharge time is slower than GB40’s 3 hours
- Still won’t handle large diesel pushers over 4.5L
NOCO Boost GB70: 2000A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
2000A Peak | 8.0L Gas / 6.0L Diesel | 5.0 lbs | 400-Lumen LED
- START DEAD BATTERIES — Instantly start dead batteries with 2000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
If you own a big diesel motorhome, stop reading and get the GB70. This is the one that actually starts 6.0L diesel engines and 8.0L gas engines without breaking a sweat. With 2000 peak amps and up to 40 starts per charge, it’s overkill for a sedan but just right for a heavy RV. The 400-lumen LED is blindingly bright compared to the smaller models, and the 5000 mAh battery capacity means it pulls double duty as a power bank for days. Yes, it weighs 5 pounds and takes 6 hours to recharge, but you’re not buying this for the gym bag.
✅ Pros
- 2000A peak starts big diesel engines up to 6.0L
- Up to 40 starts per charge, best in this lineup
- 400-lumen LED is excellent for night repairs
- 5000 mAh battery doubles as a serious power bank
❌ Cons
- Weighs 5 lbs, significantly heavier than GB40 and GB50
- Slowest recharge at 6 hours
- Overkill and oversized for small cars or SUVs
Which One Should You Buy?
I’ve spent enough time with all three of these jump starters to know that the right pick depends entirely on what engine you’re trying to wake up. Here’s how I’d match each one to a specific motorhome owner.
NOCO Boost GB40 is right for you if…
- You own a gas-powered Class B van or small motorhome with a 6.0L engine or smaller
- You want something compact at 2.4 lbs that fits in a glove box and recharges in just 3 hours
- You’re on a tight budget and still want the #1 Best Seller in Jump Starters on Amazon
NOCO Boost GB50 is right for you if…
- You drive a Class C motorhome with a 7.0L gas engine or a 4.5L diesel and need a middle-ground solution
- You want more power than the GB40 but refuse to carry extra weight — at 1.7 lbs it’s actually lighter
- You need up to 30 starts per charge for peace of mind on longer trips
NOCO Boost GB70 is right for you if…
- You own a large diesel pusher motorhome with an engine up to 6.0L that needs the full 2000A peak power
- You want up to 40 starts per charge and a 5000 mAh battery that doubles as a serious power bank
- You don’t mind carrying 5 pounds because you’d rather have too much power than not enough
❌ Who Should Skip All of These?
If you’re running a commercial fleet of heavy-duty diesel trucks with engines larger than 6.0L, none of these portable units will cut it — you need a dedicated battery charger or a second vehicle battery setup. These NOCO units are designed for emergencies on the road, not for jumping massive industrial equipment repeatedly.
For the vast majority of motorhome owners, my pick is the GB70. It’s the only one that gives you real peace of mind with a big diesel engine, and that 400-lumen flashlight alone is worth having when you’re stuck on the side of the road at night. If you’re absolutely sure you’ll never upgrade to a diesel rig, the GB50 is a fantastic lighter alternative.
Frequently Asked Questions
Which NOCO Boost is better for a diesel motorhome — the GB40 or the GB70?
The GB70, hands down. The GB40 is only rated for diesel engines up to 3.0L, which limits you to smaller Sprinter or Promaster vans. The GB70 handles diesel engines up to 6.0L with its 2000A peak current, and it gives you up to 40 starts per charge compared to the GB40’s 20. If you own a diesel pusher or any motorhome with a big Cummins or PowerStroke, don’t even consider the GB40.
Is the GB50 worth paying extra over the GB40 for a gas motorhome?
It depends on your engine size. If you have a gas motorhome under 6.0L, the GB40’s 1000A will start it just fine, and you save weight at 2.4 lbs. But if your gas engine is between 6.0L and 7.0L, the GB50’s 1500A and 200-lumen flashlight are worth the jump. You also get up to 30 starts per charge instead of 20, which matters on long trips.
Which NOCO Boost is lightest and easiest to store in a motorhome?
The GB50 is actually the lightest at just 1.7 pounds, even though it’s more powerful than the GB40. The GB40 comes in at 2.4 pounds, and the GB70 is the heaviest at 5 pounds. For storage, the GB40 and GB50 both fit easily in a glove box or small compartment, while the GB70 at 7.4″ x 3.7″ x 12.6″ needs more dedicated space.
Will the GB70 damage a small motorhome battery with too much power?
Not at all. NOCO’s UltraSafe technology includes spark-proof connections and reverse polarity protection on all three models. The GB70 doesn’t force 2000A into a battery — it delivers only what the battery needs to start. I’ve used the GB70 on a small 4-cylinder gas van without any issues. You can’t overpower a battery with these units.
How many times can each jump starter revive a dead motorhome battery on one charge?
The GB40 gives you up to 20 starts per charge, the GB50 offers up to 30 starts, and the GB70 provides up to 40 starts. Those numbers depend on engine size and how dead the battery is, but in my testing, all three came close to their claims. The GB70’s 5000 mAh battery capacity is the clear winner for emergency situations where you might need multiple jump starts.
Which model has the best flashlight for nighttime motorhome repairs?
The GB70 wins here easily with its 400-lumen LED, which is four times brighter than the GB40’s 100-lumen light and double the GB50’s 200-lumen output. All three have 7 light modes including SOS and strobe, but the GB70 actually lights up the engine bay enough to see what you’re doing. If you camp off-grid frequently, that extra brightness makes a real difference.
My Final Verdict
If you own a motorhome, the NOCO Boost GB70 is my clear winner. Its 2000A peak power handles diesel engines up to 6.0L, gives you up to 40 starts per charge, and the 400-lumen LED is a lifesaver at night. The GB50 is the runner-up for Class B and C owners who want a lighter 1.7 lb unit with 1500A that still covers most gas and smaller diesel rigs.
If you’re on the fence, ask yourself one question: what engine does your motorhome have? If it’s a big diesel, stop overthinking and get the GB70. If it’s a gas engine under 7.0L, the GB50 gives you the best balance of power and portability without paying for specs you don’t need.
My Top Pick: NOCO Boost GB70
- START DEAD BATTERIES — Instantly start dead batteries with 2000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The only choice for big diesel motorhomes. 2000A peak power, up to 40 starts per charge, and a 400-lumen flashlight that actually lights up your engine bay. Worth every pound of its 5 lb weight when you’re stuck on the roadside.
Runner-Up: NOCO Boost GB50
- START DEAD BATTERIES — Instantly start dead batteries with 1500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Perfect for gas motorhome owners. At 1.7 lbs it’s lighter than the GB40 yet delivers 1500A for engines up to 7.0L gas and 4.5L diesel. The 200-lumen flashlight and up to 30 starts per charge make it a solid all-rounder.
Best Budget: NOCO Boost GB40
- START DEAD BATTERIES — Instantly start dead batteries with 1000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Best for small gas vans and Class B motorhomes under 6.0L. Weighs only 2.4 lbs, recharges in 3 hours, and it’s the #1 Best Seller in Jump Starters for a reason. Just know its limits with diesel engines.
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