How to charge LiPo batteries.

The charging routine, step by step

1. Inspect the pack before it goes on the charger

Thirty seconds, every time. Look for puffing or swelling, torn shrink wrap, kinked or frayed wires, and a damaged balance plug. A pack that fails inspection doesn't get charged — it gets retired (see the disposal notes below).

2. Let a just-run pack cool down

Never charge a warm battery. After a run, set the pack aside until it's room temperature — usually fifteen to twenty minutes. Charging a hot pack accelerates wear and can push a marginal cell over the edge.

3. Connect both leads and pick balance-charge mode

Plug in the main power lead and the white balance lead, then select LiPo balance-charge mode, set the cell count (2S or 3S), and set the charge current using the 1C rule below. Confirm the cell count the charger detects matches the label on the pack before you press start.

4. Charge in a LiPo bag, on a safe surface, while you're nearby

Pack in a LiPo-safe bag or charging box, bag on tile, concrete, or another non-flammable surface, away from anything that burns. Stay in the room. A healthy pack at 1C finishes in about an hour, and it should never get more than slightly warm.

5. Unplug promptly and store correctly

When the charger beeps, take the pack off. Running tomorrow? A full charge overnight is fine. Not running for a few days or more? Put it back on the charger in storage mode first — your packs will thank you with seasons of extra life.

Balance charging, explained

A 2S pack is two lithium cells in series; a 3S is three. A fully charged cell reads 4.20 volts, so a full 2S shows 8.4V and a full 3S shows 12.6V. The catch: the cells inside a pack are never perfectly matched, and they drift apart a little with every cycle.

A plain (non-balance) charger only watches the total. It would happily push a 2S pack to 8.4V even if one cell sat at 4.35V and the other at 4.05V — and that overcharged cell is exactly where swelling and failures start. A balance charger reads every cell individually through the balance lead and bleeds or slows the high cells so they all arrive at 4.20V together. That's why the rule on this site is absolute: balance charge, every charge, no exceptions. Crawlers sip current slowly, which makes it tempting to treat packs casually — resist. The balance lead is not optional equipment.

Still shopping for a pack? Our best LiPo for crawlers guide picks the right battery for each scale — this guide picks up where it leaves off.

Charge rates and the 1C rule

Charge current is measured in amps, and the safe way to pick it is the C-rate. 1C means the pack's capacity, in amp-hours, as amps. A 5000mAh (5.0Ah) pack at 1C charges at 5.0 amps. A 2200mAh pack at 1C charges at 2.2 amps. A tiny 650mAh micro pack at 1C charges at just 0.65 amps. At 1C, a charge from storage voltage takes about an hour.

Some packs are labeled for 2C or faster charging, and modern cells tolerate it — but heat is the enemy of cell life, and crawling has no pit stops. There's no trophy for finishing a charge in thirty minutes. Charge crawler packs at 1C or below, and they'll repay you with years of service. The other number that matters is charger watts: a 25W charger can only push about 3 amps into a 2S pack no matter what you dial in, so big packs charge slowly on small chargers. 50W is the practical floor for 1/10 crawling; dual-channel and 100W-plus chargers earn their keep when you run several trucks.

Storage voltage: the habit that doubles pack life

A lithium cell is happiest resting in the middle of its range — about 3.8 volts per cell (7.6V for 2S, 11.4V for 3S). Park a pack fully charged for a month and the chemistry quietly degrades: capacity shrinks, internal resistance climbs, and the pack starts to puff. Park it fully discharged and the voltage can sag below the point where a charger will revive it at all.

The fix is one button. Every charger worth owning has a storage mode that charges or discharges each cell to storage voltage automatically. Rule of thumb: if the truck won't run again within about a week, storage-charge the pack. Store packs somewhere cool and dry, in a LiPo-safe bag or a vented metal ammo can, away from direct sun and anything flammable. Spektrum's Smart packs deserve a mention here: G2 Smart batteries can be set to auto-discharge themselves down to storage voltage after a set number of hours, which is a genuinely useful trick for forgetful humans.

Connectors you'll meet on crawlers

IC2 and IC3 (Spektrum Smart / EC)

Spektrum's current standard. The tiny IC2 shows up on micro packs like the 650mAh 3S Trail Pro; IC3 handles 1/10 surface packs and is physically compatible with older EC3 plugs. Smart packs add a data wire that lets a Smart charger read the pack and set itself up. The Gens Ace Bashing 2S in our catalog ships with an EC3, so it plugs straight into IC3-equipped trucks.

Deans (T-plug)

The hobby's old workhorse — a red T-shaped plug you'll find on tons of budget and mid-range packs, including the Ovonic and CNHL packs below. Perfectly fine at crawler currents. If your truck and battery disagree on plugs, a quality adapter is acceptable for crawling, though a properly soldered matching plug is always the cleaner answer.

XT60

The yellow plug common on EcoPower and many aftermarket packs. Rated well beyond crawler needs and easy to solder, which is why builders like it.

Traxxas iD

Traxxas's proprietary plug on TRX-4 and TRX4M packs. iD packs carry their settings in the plug, and they only balance-charge on Traxxas iD chargers — third-party chargers can't read the balance data through the iD connector. If your fleet is Traxxas, budget for their charger; if it's mixed, standard plugs keep your options open.

JST and micro plugs

Most 1/24 and 1/18 RTRs run small JST-style plugs on their little 2S packs, and many include a simple USB charger in the box. Those work, but a real balance charger with the right lead is more accurate and much faster — and the balance plug on the pack (a small JST-XH connector) is the same style found on full-size batteries.

Browse every plug and pack we track on the batteries page.

2S or 3S for crawling?

Same charging rules either way — the choice is about how the truck drives. 2S (7.4V) gives smooth, controllable low-speed throttle and is gentle on drivetrains, which is why most trail trucks ship 2S-ready and most drivers never need more. 3S (11.1V) adds wheel speed and punch: helpful for brushless rigs, big tires, and steep comp lines where you need a burst to bump up a ledge. The price is more heat, more drivetrain stress, and a truck that gets jumpy at low throttle if the gearing isn't right.

Comp crawlers split the difference with small 3S shorty packs — the voltage of 3S with the weight placed low and forward. Whatever you choose, confirm your ESC and motor are rated for it before the first run, and set the ESC's low-voltage cutoff for LiPo so the truck tells you when the pack is done. Never run a LiPo below 3.0 volts per cell under load; a pack dragged down there is damaged goods.

Chargers worth buying: budget (under $40)

Real balance chargers that get the fundamentals right.

Mid-range chargers ($40–$130)

More watts, storage modes, cell health data, and room to grow.

Every charger we track lives on the chargers page — including the flagship Spektrum S2200 G2 dual Smart charger ($319.99) for high-volume benches.

Packs that pair well with these chargers

Charging is only half the system — here are catalog packs worth feeding.

Choosing between these packs? The best LiPo for crawlers guide compares them by truck and scale.

Safety rules that are not negotiable

Never leave a charging pack unattended

LiPo failures are rare, but when a damaged or mis-set pack lets go it does so fast and hot. Charge while you're in the room, every time. If you can't be there, don't start the charge.

Charge and store in a LiPo-safe container

A flame-resistant LiPo bag costs a few dollars and contains the worst case. Charge in the bag, store in the bag (or a vented metal ammo can), and keep both on a non-flammable surface away from solvents, paper, and the rest of the flammable clutter every garage accumulates.

Respect damaged and puffed packs

Swelling means gas from degrading chemistry — the pack is telling you it's done. Don't charge it, don't run it, don't puncture it to let the pressure out, and don't toss it in household trash. Keep it somewhere cool and non-flammable, then take it to a hobby shop, battery retailer, or hazardous-waste drop-off that accepts damaged lithium batteries.

Mind the voltage floor and the ESC cutoff

Enable the LiPo low-voltage cutoff on your ESC and actually stop when it triggers. A cell pulled below 3.0 volts under load suffers permanent damage, and trying to force-charge a deeply over-discharged pack is how bad days start. If a charger refuses a pack because a cell reads too low, believe it.

Buy the charger before the second battery

If there's one theme to this whole guide, it's that the charger is safety equipment, not an accessory. A proper balance charger with storage mode — even the $26.99 EcoPower above — protects every pack you'll ever own.

A quick note on links

Some links on this page are affiliate links. If you buy through them, the retailer may pay us a commission at no extra cost to you — it keeps the lights on and the deal verification going. Prices were verified Oct 12, 2026; the live deal pages always show the current verified total. RC Crawlers Seek currently tracks 3,545 hand-verified deals.