Best LiPo Batteries for the SCX24 and TRX4M (And What to Know Before You Buy)

March 15, 2026

The stock battery that comes with most micro crawlers does the job. It’ll get you running, give you a feel for the truck, and last long enough for a reasonable first session. But it’s also usually the smallest, cheapest pack that fits in the battery bay — and once you’ve run a few packs and started wanting more run time or more consistent power delivery, the upgrade question comes up pretty quickly.

Here’s what you actually need to know, without the magic pixie theory.

What Size Battery Does Your Truck Use?

Before anything else, the spec that matters: both the SCX24 and TRX4M run 2S LiPo packs (7.4V nominal). That part is consistent across both platforms. The difference is physical size.

SCX24: The stock pack is a 350mAh 2S. The battery bay is tight — not all aftermarket packs fit without modification. Some body styles have slightly more clearance than others, which affects how much headroom you have to go larger.

TRX4M: The stock pack is a 750mAh 2S. Traxxas designs their battery bays for Traxxas packs, so confirmed-fit packs are worth finding before ordering. The TRX4M is somewhat more tolerant of slightly larger packs than the SCX24, but verify dimensions before buying.

Measure your battery bay, or check the community forums for confirmed fits on your specific truck version before ordering anything.

What to Upgrade To

For the SCX24

The stock 350mAh pack is functional but short — most runs clock in around 15–20 minutes before the truck starts feeling weak. The goal is more capacity in roughly the same footprint. Going from 350mAh to 450–600mAh meaningfully extends your run time and makes trail sessions feel a lot less interrupted.

Gens Ace 2S 450mAh LiPo — Gens Ace is one of the most trusted names in RC batteries across all scales. Their micro packs are well-built, hold voltage consistently through a run, and the quality control is reliable. Check the dimensions against your bay before ordering.

Venom 2S 500mAh LiPo — Venom has solid community validation for fit and reliability in the SCX24. The 500mAh target gives you roughly 25–30+ minutes per pack depending on terrain and driving style.

If your specific SCX24 body style has extra clearance, going up to a 600mAh pack is worth investigating. At the low power draw of a brushed micro crawler, a bigger pack doesn’t create heat or stress — you just get more time on the trail.

For the TRX4M

The TRX4M is heavier than the SCX24 and draws more power on demanding terrain. The stock 750mAh pack is a decent starting point, but stepping up to 1000–1500mAh is where you start to notice the difference on longer trail days.

Traxxas 2S 1000mAh LiPo — The most straightforward upgrade for TRX4M owners already in the Traxxas ecosystem. Guaranteed fit, compatible with the Traxxas ID charger, and 60% more capacity than stock.

Gens Ace 2S 1000mAh LiPo — Gens Ace is a well-regarded brand at a lower price per mAh than Traxxas. If you have a balance charger already, this is a solid option. Verify dimensions against your bay — the Bronco and Land Rover body styles have slightly different geometry.

How Many Packs to Buy

Two packs is the right starting number. Here’s the logic: while one pack is running, the other is cooling down and charging. You get continuous running time instead of waiting between sessions. A good balance charger handles one pack in 30–45 minutes, which means a two-pack rotation keeps you on the trail almost continuously.

If you’re going to a trail day or running with a group, three packs is even better.

The Charger Question

The wall charger that comes in the box with most RTR crawlers is what hobbyists call a trickle charger or brick charger. It works — slowly, and without balancing the individual cells in the pack, which matters for battery longevity and safety.

A proper balance charger is worth owning if you’re going to run LiPo packs regularly. Balance charging means the charger monitors and equalizes the voltage across each individual cell in the pack, which keeps the pack healthier longer and reduces the small but real risks that come with unbalanced cells.

ISDT Q6 Plus — The charger I’d recommend for anyone getting serious about RC batteries. Handles 1S through 6S, charges quickly at adjustable rates, has balance charging built in, and the interface is straightforward once you’ve used it a couple of times. Buy-once gear.

If you’re not ready to spend on a full charger yet, at minimum make sure you’re not leaving the stock charger unattended. Trickle chargers don’t have the cutoff intelligence that a proper charger does.

The One Non-Negotiable: LiPo Safety Bag

If you remember one thing from this article, make it this: charge LiPo batteries inside a fireproof charging bag.

LiPo fires are rare. They’re also fast, hot, and serious when they do happen — usually caused by a damaged pack, overcharging, or a shorted cell. A LiPo safe charging bag costs a few dollars, contains a potential fire to the bag instead of your house, and takes exactly zero effort to use. Put the pack in the bag, connect the charger, walk away.

This is not optional. It’s five dollars of insurance against a genuinely bad outcome.

Storage Charging: The Other Thing Nobody Talks About

One more thing worth knowing: LiPo batteries shouldn’t be stored fully charged or fully discharged. Both conditions degrade the cells faster than normal use does.

If you’re not going to run for a few days or more, charge your packs to storage voltage — roughly 3.8V per cell, or 7.6V for a 2S pack. A quality charger like the ISDT Q6 Plus has a storage charge mode that does this automatically. The stock brick charger doesn’t have this feature, which is another reason a real charger is worth owning.

Packs stored at the right voltage last significantly longer than packs that get charged and then sit fully loaded in a drawer for weeks.

Quick Reference

Pack	Platform	Capacity	Notes
Gens Ace 2S 450mAh	SCX24	450mAh	Step up from stock 350mAh
Venom 2S 500mAh	SCX24	500mAh	Community-validated fit
Traxxas 2S 1000mAh	TRX4M	1000mAh	Easy ID ecosystem upgrade from stock 750mAh
Gens Ace 2S 1000mAh	TRX4M	1000mAh	Great value, verify fit
ISDT Q6 Plus charger	Both	—	Balance charger, buy-once
LiPo safe bag	Both	—	Non-negotiable

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