Let's get started... How to look after your motorcycle battery | Troubleshooting and recovery guide

Motorcycle battery maintenance is a key element to ensuring you can enjoy your riding as much as possible. There is nothing worse than excitedly approaching your bike only to find the starter won’t spin over (even though the kill switch is on and it’s in neutral… we’ve all been there) because the battery is flat.

There are several types of batteries. The most common is (or was) the lead-acid wet-cell type which in past times was accessible though now is less common. This type featured lead plates suspended in a solution of acid and distilled water and each cell (there were six in 12V batteries and three in 6V ones) could have its water topped up to maintain a certain level.

Lead-acid wet-cell batteries have eventually phased out. They were replaced by sealed, maintenance-free batteries where the acid is held in glass fibre matting. Any gasses produced by the chemical reaction generating the electricity were re-absorbed into the liquid, so they didn’t require any topping up.

Gel batteries work on a similar principle but instead of familiar liquid, the acid is more of a gel-like consistency and these kinds of batteries can be mounted on their side instead of standing upright.

• Related: Best motorcycle jump packs

Finally, the increasingly common lithium battery, with the numerous scare stories that accompany them.

However, these are largely unfounded: these batteries produce the same electrical power but more efficiently. They are lighter than other options, but also require slightly different motorcycle battery maintenance charging regimes.

Generally speaking, a 12V motorcycle battery will have six separate cells joined electrically, each generating 2V. A fully-charged battery in its resting state should show a voltage of around 12.8V, dropping to one that is around 1/4 charged showing 11.7V and a totally discharged battery showing around 10.5V. If yours shows less than that, it is certainly time for a recharge and possibly, a new battery.

With the engine running, the voltage across the battery terminals should be in the region of 14.4V – any supply voltage higher than around 12.5 will recharge the battery. However, it’s worth remembering that many modern bikes will have a slight parasitic drain on the battery when they are stood – ECUs will require some power, however minor, to maintain a memory function and a tracker, if fitted, can drain a battery in a few days or weeks.

Fitting a charger for motorcycle battery maintenance is always a good idea, whether you leave it for a couple of days (over the weekend say) or lay it up for winter. Don’t forget that electricity is generated by a chemical reaction within the battery and lower temperatures always slow this process.

A charger that has a maintenance function will vary the charging cycles to prevent long-term damage as well as automatically detect the type of battery and adopt the right charging strategy for it (lead-acid, lithium etc).

A flat battery can occur because the battery is nearing the end of its life and is struggling to maintain charge – and it’s worth pointing out that cheaper batteries will fail much quicker than some of the leading brands. Having a remote charge lead to the battery and connected to a charger is the only way to maintain a battery in peak condition.

Here’s our motorcycle battery maintenance guide:

How low can it go?

If your bike turns over slowly and won’t start, it doesn’t always mean the battery is knackered. Often the bike’s alarm, immobiliser or tracking device can drain the battery enough to prevent the engine from cranking over. Partial discharge down to nine volts on a relatively new battery is recoverable – use a multimeter to take a voltage reading, as shown here.

Take charge

If you have time, it’s always better to give the battery a proper charge. Make sure the bike’s ignition switch is in the off position then connect a charger to the battery. If the battery is discharged to a lower voltage than the charger’s minimum threshold then it won’t be able to charge it, so check the charger’s specifications.

• Bruce’s tip: Maintenance mode may help recover a low-voltage battery

Jump to it

If your battery has failed while you’re out and about, a jump-start can help you get back on your way. There is a new generation of jump-starters, including this Noco GBX55 (£139.96 Amazon), that are extremely compact and can deliver enormous amperage thanks to a lithium battery – up to 1750 amps. That’s more than enough to start large-capacity engines.

Before you can jump-start…

…remove any panels required to allow the crocodile clips to grip the battery terminals. This Triumph Street Triple needs only to have the seat removed plus a plastic shroud that covers half of the battery. With all of these bits removed the jump leads can be safely attached.

• Bruce’s tip: Don’t perform a jump-start on a lithium-ion battery

Grip with the clip

Connect the red lead to the positive terminal. Don’t let the crocodile clips touch anything metallic that’s near the terminal – that’ll cause a direct short circuit, resulting in damage to surfaces or the battery. With the red lead secure, attach the black lead to the negative terminal.

Press to assess

A jump-starter pack like this is more sophisticated than the old-school running jump leads off another vehicle’s battery. Once the pack is connected, pressing a button lets it assess battery condition before energising the jump leads – they’re not live until that point.

Turn on – and wait!

Next, turn the ignition on and wait a few seconds for the fuel pump and electronics to initialise. Most modern bikes will run through a sequence of system checks. As a rule, once the dash has finished cycling its welcome screen and check lights, the bike will be ready to start.

• Bruce’s tip: Still won’t start? Check the jump-lead connection on the battery

Don’t push it (well, not too much)

Press the starter button and allow the engine to crank over – it should start straight away. If it doesn’t, only keep the starter motor running for 15 seconds at a time – keeping it running for too long can cause it to burn out. With the bike now idling, you can remove the jump leads.

Warm up and test ride

With the jump leads off, replace any panels you removed. Allow the bike to idle until the engine is fully warm then go for a 15-minute ride. Then turn off and try to restart – all being well the battery will have recovered with no problems. If not, there may be a charging fault.

• Bruce’s tip: When you get it running, don’t turn the engine  off until you’re home