ICON Golf Cart Lithium Battery Guide: Onboard Charger, 450A Controller, and the Three Situations
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Most golf cart lithium guides treat ICON like a Club Car with different plastics. It isn’t. An ICON i20, i40 or i60 has an onboard charger built into the cart, sealed AGM batteries rather than flooded lead-acid, a 350A or 450A AC controller, an electromagnetic parking brake, and a digital cluster that expects battery data. Since 2021 many ICONs shipped with a factory 51V 105Ah Eco Battery lithium pack, and from 2025 that pack is standard across the range. So “putting lithium in an ICON” means one of three quite different jobs. This guide separates them, explains the electrical details that decide which pack works, and covers the install.
First: Which of the Three ICON Situations Are You In?
| Your cart | What’s under the seat | The job |
|---|---|---|
| A. AGM lead-acid ICON (most 2018 to 2023 carts) | Six 8V or eight 6V sealed AGM batteries | Full conversion: new pack, new charger, brackets, dash decision |
| B. Factory lithium, want more range | One 51V 105Ah Eco Battery pack | Capacity upgrade: swap to 150Ah+, or add a second pack in parallel |
| C. Factory lithium, pack failed | One Eco Battery pack, cart dead or won’t charge | Replacement: aftermarket pack, or Eco Battery under its 8-year warranty first |
Situation C has a step people skip: Eco Battery’s pack on ICON carts carries an 8-year warranty. Before buying anything, check the pack’s date code and contact Eco Battery or the ICON dealer. A warranty replacement costs nothing; an aftermarket pack costs $700 to $1,600. Only move to aftermarket if the warranty is gone or the claim is denied.
ICON Electrical Facts That Change the Conversion
| Model | Stock batteries | Motor / controller | Why it matters for lithium |
|---|---|---|---|
| i20, i20L | Six 8V AGM, or Eco lithium | 4 or 5 kW AC, 350 to 450A | Two-seater, lightest load; 105Ah is plenty |
| i40, i40L | Six 8V AGM, or Eco lithium | 5 kW AC, 450A | 450A controller peak; BMS rating matters |
| i40F, i40FL | Eight 6V AGM, or Eco lithium | 5 kW AC, 450A | Eight-battery tray is larger; more room, more securing |
| i40-ECO, i40L-ECO | Six 8V or eight 6V AGM, or Eco lithium | 4 kW AC, 350A | Lower draw; 200A BMS is comfortable |
| i60, i60L, i60F | Eight 6V AGM, or Eco lithium | 5 kW AC, 450A | Six passengers; 150Ah minimum for real range |
| i80 | Eight 6V AGM, or Eco lithium | 5 kW AC, 450A | Eight passengers; 150 to 160Ah, or two packs |
Configurations from ICON EV model pages and dealer specifications. Battery count varies by model year even within a model; count yours.
The 450A controller and your BMS
ICON’s standard controller is rated 450A. That is a peak figure the controller can command for a few seconds when you floor it from a stop or start up a grade with four people aboard. A typical aftermarket pack has a 200A continuous BMS with a 1000A burst rating for three to five seconds. In normal driving the two coexist fine: the controller’s average draw on flat ground is well under 100A. Where they collide is sustained load: a lifted i40L on 23-inch tires climbing a long hill can hold the controller above 200A for longer than the BMS burst window, and the BMS opens. The cart lurches, the dash blanks, and a second later it recovers. If that’s your terrain, a 250A continuous pack is the right spec, not a bigger amp-hour number. The Cloudenergy 48V 105Ah is the 250A option in our 48V comparison.
AGM is not flooded lead-acid
ICON’s stock batteries are sealed AGM. They don’t need watering and they don’t leak, so the tray under an ICON is usually clean; the acid neutralising step that matters on an old EZGO is rarely needed here. AGM sets also tend to die more suddenly than flooded ones, which is why ICON owners often go from “fine” to “won’t hold a charge” in a season. If yours is doing that, the set is at end of life, not one bad battery.
The Onboard Charger: ICON’s Real Complication
Every other cart on this site uses an external charger that plugs into a receptacle on the cart. ICON mounts the charger inside the cart, under the seat, with a wall cord on the body and a charge indicator light on the fender. That changes three things.
- The fender charge indicator will stop working. It was driven by the factory charger. Kits either ignore it or provide their own indicator on the new charger. Not a fault.
If you buy a bare pack rather than a kit, you’ll need a standalone 48V lithium charger and a way to connect it. ICON lithium models typically use an Anderson SB50 connector at the pack; 48V LiFePO4 chargers with the SB50 connector plug straight in and can be mounted under the seat. More on chargers in the charger compatibility guide.
The Dash: Three Ways to Handle State of Charge
ICON’s digital instrument cluster shows state of charge from the battery. With AGM it reads voltage; with the Eco Battery pack it reads data over a CAN bus link. An aftermarket pack breaks that link, so you have three options:
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- Integrated kit. Allied’s ICON kit ships with a CAN/RS485 harness and a replacement digital head unit that plugs into the ICON dash position and reads the Allied pack directly. It’s the only route that keeps a dash-mounted, factory-looking gauge. Costs more, and it’s sold through dealers and specialist retailers rather than Amazon.
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- Kit with its own display. Vatrer’s ICON kit includes a small touchscreen meter that mounts on the dash or under the seat. Accurate, cheap, not integrated.
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- Bluetooth app only. Any pack with an app. Fine if you’re happy to check your phone.
Whichever you choose, expect the factory cluster’s battery bar to be blank, frozen or wrong after the swap. The cart still drives; the cluster’s speed, odometer and warning lights keep working.
The Parking Brake Draws Power When Parked
ICONs use an electromagnetic parking brake, the same approach as the EZGO RXV. The controller and brake circuit stay awake in Run mode with the key off, pulling a small continuous current. On AGM this was invisible. On lithium, a cart left for several weeks at a low state of charge can reach the BMS low-voltage cutoff, at which point the pack disconnects, the brake locks and the cart is immobile until the pack is woken and charged. Two habits prevent it: charge after use rather than before, and use the Tow/Maintenance switch for storage longer than a couple of weeks. Recovery, if it happens, is the BMS wake procedure in Cause 1 of the won’t-charge guide.
What to Buy for Each Situation
A. Converting an AGM ICON
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- A kit made for ICON is the low-friction route: pack, charger that fits the onboard mount, brackets, longer cables, and a meter. The Vatrer 48V 105Ah is sold in an ICON-specific kit listing that names the i20, i40, i40F, i40-ECO and i60; check that you’re on the kit variant, not the bare pack. For i60, i80 or lifted carts, the Vatrer 48V 150Ah.
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- Or a bare pack plus an SB50 charger if you’re comfortable fabricating a charger mount. Any pack in the 48V comparison fits the ICON tray; choose 250A BMS for lifted or hilly use.
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- Hold-down hardware. Kits include brackets. One owner installing a Vatrer kit in an i40 reported minor trimming in the battery compartment to seat the pack; have a rotary tool available and expect to fit the pack opposite the driver’s side.
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- Probably no reducer. ICONs have a factory DC-DC converter for the lights, USB and 12V outlets. Test after the swap; if everything works, you’re done. If not, the Pro Chaser 30A and our reducer guide.
B. Upgrading a factory Eco Battery pack for range
Two paths. Swap the 105Ah for a 150 or 160Ah pack, which is a straight replacement and gives roughly 45% more range. Or keep the factory pack and add a second identical Eco Battery pack in parallel, which doubles range, doubles available BMS current, and keeps the dash integration; Eco Battery sells the harness. The parallel route only works with a matching Eco Battery pack, not a mixed brand, and the second pack needs a mounting location, usually under the rear seat or in a rear-mounted tray on lifted carts. For most owners the 150Ah swap is simpler; for i60 and i80 owners who tow or run hilly resort duty, the parallel pair is worth pricing.
C. Replacing a failed factory pack
Warranty first, as above. If that’s exhausted, the options are identical to Situation A minus the AGM removal. One difference: the factory onboard charger on lithium-model ICONs is set for the Eco Battery pack, and it may or may not accept an aftermarket pack’s charge profile. Budget for a charger in the kit, and if the factory unit happens to work you have a spare.
Install: Where ICON Differs From the Usual Steps
The generic sequence (Tow mode, negative off first, remove batteries, clean, set and secure the pack, positive on, negative on, test) applies. These are the ICON-specific parts:
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- Unplug the cart from the wall and disconnect the onboard charger’s DC output leads from the battery pack before anything else. On an ICON the charger is part of the pack circuit; on other carts it’s just a receptacle.
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- Remove the onboard charger (two or three bolts) and mount the kit charger in its place. Reconnect the wall cord’s AC side to the new charger per the kit diagram. If the new charger has its own AC cord, route it to the body cord location or use the new cord through the same opening.
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- Eight-battery trays (i40F, i60, i80) leave a lot of empty space around one pack. Use the kit brackets plus a bolted spacer or a foam block; a strap alone will let the pack creep forward under braking.
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- Disconnect the factory CAN connector if the cart had an Eco Battery pack and you’re fitting a non-integrated aftermarket pack. Tape it; don’t cut it. A future owner may want the factory pack back.
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- Connect the charger’s DC output to the new pack terminals, then test the charge cycle before you close the seat. On ICON the charger is bolted in; you don’t want to discover a wiring error after everything is buttoned up.
Troubleshooting After the Swap
| Symptom | Most likely cause | Fix |
|---|---|---|
| Fender charge light dead | It was driven by the factory charger | Normal; use the new charger’s indicator |
| Cluster battery bar blank or frozen | No CAN data from aftermarket pack | Normal; use kit meter or app, or an integrated kit |
| Cart lurches and dash blanks for a second on hills | BMS continuous rating exceeded by the 450A controller | 250A BMS pack, or two packs in parallel |
| Cart dead after weeks parked, brake locked | Parking brake draw reached BMS cutoff | Wake BMS, charge, use Tow mode for storage |
| Factory charger runs then stops | AGM or Eco profile rejecting aftermarket pack | Fit the kit charger |
| Lights/USB dead | Rare on ICON; factory DC-DC converter disconnected during install | Reconnect converter input to pack; add a reducer only if the converter is absent |
| Pack won’t seat, seat won’t close | Compartment lip interfering | Minor trimming, as ICON kit owners report; or fit on the passenger side |
Frequently Asked Questions
Can I use the ICON onboard charger with an aftermarket lithium battery?
Don’t count on it. Newer ICON chargers list a LiFePO4 mode in their manual, but ICON does not support third-party lithium and the profile may not match your pack. Kits made for ICON include a replacement charger that mounts in the factory position.
What lithium battery does an ICON golf cart come with?
Since 2021 ICON’s optional, and from 2025 standard, pack is a 51V 105Ah Eco Battery lithium unit with an 8-year warranty. Check warranty status before replacing a failed one.
Will the ICON dash show battery level with a different lithium battery?
Only with an integrated kit that includes a CAN harness and replacement head unit. Otherwise the cluster’s battery bar stops being accurate and you use the pack’s meter or app.
Is a 200A BMS enough for an ICON i40?
For a stock i40 on flat terrain, yes. For an i40L on big tires, an i60 loaded with six people, or anything on sustained hills, choose 250A. The controller is rated 450A and can hold a 200A BMS past its burst window on long climbs.
Does an ICON need a voltage reducer for lithium?
Usually not. ICONs have a factory DC-DC converter for lights and 12V outlets. Test after the conversion; add a reducer only if accessories are dead.
Next Steps
Size the pack for your ICON with the range calculator (choose “lifted” for any L model), compare BMS ratings in Best 48V Lithium Golf Cart Battery, and see the full model table in the fitment guide. Evolution owner? The Evolution guide covers a similar factory-lithium situation.