Charge, maintain & jump-start a flat battery?

Steps

1. 1
   1

   Identify the battery type first

   Find the battery (under the seat or a side panel) and read the label: lead-acid / AGM or lithium (LiFePO4). This matters more than anything else here, because the two need different chargers. Note the voltage (almost always 12 V) and where the terminals are.

   Warning

   Danger
2. 2
   2

   Disconnect first if you're removing it

   You can usually charge in place, but if you remove the battery, always disconnect the negative (-) terminal first, then the positive (+) - it avoids a spanner shorting live to the frame. Reverse the order to refit (positive first, negative last).

   Warning
3. 3
   3

   Connect a smart charger

   Clip red to positive (+), black to negative (-), select the correct mode (lead-acid or lithium) and switch on. A smart charger reads the battery and steps the charge automatically, so it's safe to leave. A fully flat battery can take several hours; let it finish rather than pulling it early.

4. 4
   4

   Keep it healthy over storage

   A battery self-discharges just sitting, and a flat lead-acid battery sulphates and dies. Over any lay-up, leave it on a maintainer / tender (a smart charger that tops up and then idles), or charge it fully every few weeks. This is the single biggest thing that decides whether it lasts three years or eight.

5. 5
   5

   Jump-starting when you're caught out

   From another 12 V vehicle (engine off): connect red to the flat +, red to the donor +, black to the donor -, and the final black to a bare metal ground on your bike away from the battery. Start your bike, then remove the leads in reverse order. Ride or charge afterwards to recover the battery.

   Danger

Fits these bikes

All motorcycles