Battery & energy

The two battery slots

The seatbox has two battery slots side by side: a front one and a rear one. In the stock hardware configuration, only the front slot is electrically connected and supplies power to the scooter. The rear slot is mechanically identical but not wired; it works as storage space, for example to carry a charged spare battery along.

A hardware mod (dual-battery operation) can wire up the rear slot as well, so both batteries supply power at the same time.

Single-battery operation (default)

Out of the box, the scooter runs in single-battery operation. The battery in the front slot supplies the power; an additional battery in the rear slot is only a spare and otherwise does nothing.

When the battery in the front slot runs low, you need to stop and swap batteries.

Swapping batteries

The swap happens while parked, entirely through the seat, with nothing else to operate:

1. Scooter in park mode, open the seat with the switch on the handlebar.
2. Lift the discharged battery out of the front slot by its handle.
3. Slide the charged spare battery from the rear slot into the front one.
4. Put the discharged battery into the rear slot.
5. Close the seat.

During the swap, the scooter stays alive on its internal backup batteries (AUX and CBB); you just can't ride in the meantime. The display's indicators update automatically once the new battery is detected.

Dual-battery operation

Dual-battery operation requires a hardware retrofit of the rear battery slot, so it's wired up as well and can communicate with the battery inside it. This retrofit is a separate hardware measure and isn't part of the stock configuration. Ask in the Discord for the current options if you're interested.

With the retrofit, both battery slots are active at the same time. Both batteries supply power in parallel, which can extend the usable range considerably – the actual gain depends on both packs and how you ride. On the display's energy gauge, you'll notice dual mode as a higher scale for power draw.

After the retrofit, you can switch the mode itself at any time in Menu → Settings → Vehicle → Battery Mode, between "Single Battery" and "Dual Battery".

Voltage safety

For two batteries to work in parallel, their voltages can't be too far apart. The scooter continuously checks the difference. If it goes above a configurable limit (default 1 volt), the scooter temporarily switches off the rear slot and continues on the front one alone, until the voltages have converged closely enough again. So you don't need to do anything if you insert one full battery and one nearly empty one together.

Charging the main battery

Main batteries are only ever charged externally in the charging station, never inside the scooter. The steps:

1. Lift the battery out of the slot.
2. Place it in the charging station.
3. The LED ring on the battery's handle shows the charge level and charging progress.

If the LED ring bothers you at night, you can turn it off with the button on the battery's handle; charging continues normally either way. If you press the button while the battery is inserted in the scooter, the ring lights up briefly and shows the current charge level.

Battery indicators on the display

In the top left of the status bar, an icon with a numeric charge level appears for each connected battery slot. In the stock configuration that's exactly one icon for the front slot; with the dual-battery retrofit, a second one for the rear slot is added.

• At a normal charge level, the text appears in the display's usual color.
• At or below 20%, the text turns orange and a turtle icon appears next to it. Motor power is capped until the battery is charged again.
• Below 10%, the text turns red.
• On a hardware error, a red error marker sits over the icon; the display also shows a code from the B-series, for example "B11" for undervoltage.

If percentages feel too abstract, you can switch to a range display in kilometers in Menu → Settings → Appearance → Status Bar → Battery Display.

Backup batteries in the scooter

Inside the scooter sit two small backup batteries, the AUX battery (12 V) and the CBB battery. They keep the scooter alive during a battery swap and while it's locked. Day to day, you don't need to worry about either one. If one gets weak, the scooter reports it with an extra warning icon in the status bar or a toast at the top of the display. If the scooter sits unused for a longer stretch, a charged main battery should be in the front slot so the backup batteries don't run completely flat.

Warnings and error messages

If something unusual happens with the batteries, the scooter reports it through icons, toasts, or explicit codes:

• Low AUX voltage or critical AUX readings appear as a toast at the top of the display, along with a dedicated icon in the status bar.
• Battery error codes in the B-series (B1 through B35) indicate a specific hardware problem with the battery. What each code means and what to do about it is on Troubleshooting.
• An open seat is shown with its own icon at the top of the status bar; the scooter can't set off in that state.

What changed compared to scooterOS

What's different about battery handling compared to the original firmware is summarized on Changes from scooterOS.