5 Best Batteries for Losi Promoto MX (2026)

If you own a Losi Promoto MX, you already know how much fun it is to rip around on that little bike. What you might also know is how quickly a weak or mismatched battery can bring that fun to a grinding halt. The wrong pack doesn’t just cut your run time short. It can leave your bike feeling sluggish, underpowered, and frankly disappointing.

That’s exactly why we put this guide together. Finding a battery that fits, performs, and holds up over time takes more legwork than most people expect, especially when the shelves are loaded with options that all seem to promise the same thing. We’ve done the research so you don’t have to guess.

By the time you finish reading, you’ll know exactly which battery fits your budget, your riding style, and your Promoto MX setup. The five picks below cover everything from best value packs to high-capacity options built for longer sessions.

How We Selected the Best Batteries for Losi Promoto MX

Our team spent serious time comparing packs across a range of specs, price points, and real-world feedback before settling on these five. We weren’t looking for the flashiest marketing claims. We were looking for batteries that actually deliver.

Here are the factors that shaped our selections:

• Voltage and configuration compatibility: A 2S 7.4V setup is the standard fit for the Promoto MX, so we only considered packs that match that requirement without modification.
• Capacity (mAh): Higher capacity means longer ride time. We looked for packs that give you meaningful runtime without pushing your motor beyond safe operating limits.
• Discharge rate (C rating): A higher C rating means the battery can supply power more quickly, which directly affects throttle response and top-end performance.
• Physical dimensions: The Promoto MX battery compartment is specific. We paid close attention to pack dimensions to make sure each pick has a realistic chance of fitting properly.
• Build quality and casing: Hard case packs take far more punishment than soft case designs in RC applications. We favored hard case options wherever possible.
• Connector type: We noted plug types for each pack so you know upfront whether an adapter is needed.
• Value for money: Getting two packs for the price of one significantly changes the equation. We factored that into our overall assessment.

Every pick on this list was chosen because it clears a real bar, not just a spec sheet. Here’s what we found.

Best Batteries for Losi Promoto MX (Expert Ranking & Review)

The five batteries below represent a solid mix of capacity, discharge rate, and value. Whether you’re a casual weekend rider or someone who runs full sessions until the pack is dead, there’s an option here that fits.

1. Zeee 7.4V 2S 50C 5200mAh LiPo with T Connector: The Crowd-Pleasing Everyday Pack

This is the battery we’d hand to someone buying their first proper LiPo upgrade for the Promoto MX. The 5200mAh capacity sits in a sweet spot that delivers solid runtime without requiring a massive pack, and the 50C discharge rate gives you responsive, consistent power delivery across a typical riding session.

The hard case construction is a genuine advantage here. It protects the cells during rough landings, tumbles, and the kind of bashing that tends to happen during real-world RC riding. The dimensions come in at 138 x 47 x 25mm, so always double-check your compartment before ordering. That measurement is critical.

At 250g per pack, it’s light enough not to upset the handling balance of the bike. We found the build quality to be noticeably solid for the price, with cells that charge evenly and hold their capacity well across multiple cycles.

You also get two packs in the box, which is arguably the best part of this deal. Two batteries means twice the ride time before you’re sitting around waiting for a charge, and that alone makes this one of the strongest value propositions in this category.

Key Specs:

• Voltage: 7.4V (2S)
• Capacity: 5200mAh
• Discharge Rate: 50C
• Dimensions: 138 x 47 x 25mm
• Weight: 250g per pack
• Connector: T (Deans)
• Quantity: 2 packs

2. HOOVO 7.4V 70C 6200mAh 2S LiPo with Traxxas Plug: More Capacity, More Punch

The HOOVO 6200mAh pack steps things up in two important ways: it carries 1,000mAh more capacity than the Zeee entry-level option, and it bumps the discharge rate to 70C. Both of those numbers translate directly to longer ride sessions and sharper throttle response when you push hard.

What makes this pack stand out is its energy density. HOOVO rates it at 235Wh/kg, which means the cells are working efficiently rather than just being physically large. You’re getting performance that’s proportionate to the weight, and at around 290g per pack it’s not dramatically heavier than smaller alternatives.

The Traxxas-style plug is worth paying attention to. It works natively with Traxxas vehicles and Losi applications that share compatible connector standards, but it won’t plug into the Traxxas charger directly. You’ll need a proper LiPo balance charger. That’s not a flaw so much as a standard LiPo requirement, but it’s worth knowing before you unbox it.

We particularly liked the hard case on this one. It’s rated for at least 150 charge cycles, and the steady discharge curve means the bike doesn’t feel like it’s losing power halfway through a session.

Key Specs:

• Voltage: 7.4V (2S)
• Capacity: 6200mAh
• Discharge Rate: 70C
• Dimensions: 139 x 47 x 25mm
• Weight: 290g per pack
• Connector: Traxxas (TR) plug
• Quantity: 2 packs

3. HOOVO 7.4V 100C 7200mAh 2S LiPo with TR Plug: The High-Capacity Performance Pick

If your priority is maximum runtime and you want a discharge rate that doesn’t flinch under pressure, this is the pack to look at. At 7200mAh and a 100C discharge rate, the HOOVO 7200 is the most capable 2S battery on this list in terms of raw performance numbers.

The 100C discharge rating means this pack can supply current at a rate that most RC motors will never fully demand of it. That headroom matters because it keeps the battery cool and stable during aggressive runs, rather than running at its ceiling every time you pin the throttle.

HOOVO rates this pack at 300Wh/kg energy density, which is meaningfully higher than even its own 6200mAh sibling. The hard case is solid, and the pack ships with both a TR plug and an EC5 adapter included, giving you a bit of flexibility depending on your charger setup.

We found the cycle life on this pack to be a genuine strength. Multiple owners report running them for years with no puffing, no significant capacity loss, and no signs of heat-related wear. For anyone who runs their Promoto MX hard and often, that long-term reliability adds real value.

Key Specs:

• Voltage: 7.4V (2S)
• Capacity: 7200mAh
• Discharge Rate: 100C
• Dimensions: 139 x 47 x 25mm
• Weight: 330g per pack
• Connectors: TR plug plus EC5 adapter
• Quantity: 2 packs

4. Traxxas 2S LiPo 750mAh 7.4V 20C (Model 2821): The Official OEM Option

This one is a completely different kind of battery from the others on this list, and it’s here for good reason. The Traxxas 2821 is a small, lightweight 750mAh pack designed specifically for compact RC applications like the TRX-4M. It fits cleanly into tight battery compartments where a larger pack simply won’t go, and it comes from a brand with a long track record in RC power.

At 1.92 ounces, this is by far the lightest option on the list. That compact form factor is the whole point. If your Promoto MX setup uses a smaller battery bay or you’re running a configuration where a full-size 5200mAh hard case won’t physically fit, this is the pack that solves the problem without requiring any modifications.

The 20C discharge rate is on the conservative side compared to the other packs here, which makes this a better fit for casual riding than for high-speed performance runs. What you get in return is a very manageable, well-behaved battery that charges quickly and stores safely.

Build quality is exactly what you’d expect from Traxxas. The connector is the standard Traxxas 3-pin style, and the pack arrives on a storage charge, which is the right way to ship any LiPo. It’s a single pack rather than a two-pack deal, so factor that into your buying decision.

Key Specs:

• Voltage: 7.4V (2S)
• Capacity: 750mAh
• Discharge Rate: 20C
• Dimensions: 2.85 x 1.80 x 1.05 inches
• Weight: 1.92 ounces (54g)
• Connector: Traxxas 3-pin
• Quantity: 1 pack

5. Zeee 7.4V 2S 50C 5200mAh LiPo with XT60 Plug: The Same Great Pack, Different Connector

Think of this as the sibling to the first Zeee pack on this list. The core specs are identical: 7.4V, 2S, 50C, 5200mAh, hard case, 138 x 47 x 25mm dimensions. The one meaningful difference is the connector. This version ships with an XT60 plug instead of the T-style Deans connector on option number one.

That distinction matters more than it might seem. If your speed control, charger, or existing RC ecosystem is wired for XT60 connectors, buying this version saves you the hassle and expense of swapping plugs or running adapters. It’s a small detail that makes a real difference in day-to-day use.

Performance-wise, everything we said about the first Zeee pack applies here. The cells hold their charge well across many cycles, the hard case does a solid job of protecting the pack during rough handling, and the weight is identical at 250g per pack. We noted that some owners run these through 70-plus charge cycles with no capacity loss, which speaks well of the cell quality.

This is the pack for the XT60 crowd. If your setup runs that connector standard, this is the most straightforward 2S upgrade you can make to your Promoto MX without touching a wire.

Key Specs:

• Voltage: 7.4V (2S)
• Capacity: 5200mAh
• Discharge Rate: 50C
• Dimensions: 138 x 47 x 25mm
• Weight: 250g per pack
• Connector: XT60
• Quantity: 2 packs

Best Batteries for Losi Promoto MX: A Quick Rundown

• Zeee 7.4V 50C 5200mAh (T Connector): Best overall value with two packs and proven hard-case reliability
• HOOVO 7.4V 70C 6200mAh (Traxxas Plug): Best mid-range upgrade with more capacity and stronger punch
• HOOVO 7.4V 100C 7200mAh (TR Plug): Best for maximum runtime and serious performance headroom
• Traxxas 2S 750mAh 7.4V 20C: Best for compact battery bays and OEM-quality peace of mind
• Zeee 7.4V 50C 5200mAh (XT60): Best for XT60 setups that want proven performance straight out of the box

Final Thoughts

Picking the right battery for your Losi Promoto MX comes down to three things: physical fit, runtime goals, and connector compatibility. A pack with great specs means nothing if it won’t seat properly in the battery compartment, so always verify dimensions before ordering. Beyond fit, your ride style should drive the decision. Casual sessions call for a different pack than aggressive full-throttle runs, and your connector standard determines whether you need an adapter or a direct swap.

The good news is that you don’t have to spend a fortune to get solid LiPo performance. Whether you go with a high-capacity option for longer sessions, a compact OEM-quality pack for a tight fit, or a two-pack deal that doubles your ride time between charges, there’s a clear winner on this list for your specific situation. Pick the one that matches how you actually ride, and get back out there.