How Long Does It Take To Charge The Motorcycle Battery

Motorcycle batteries are generally kept charged by the motorcycle onboard charging system, but from time to time, they get discharged due to the how weather which increases self-discharge rate, parasite loads like alarms, and similar systems, long periods of inactivity (winter, for example) and similar.

Properly recharging semi or even fully discharged motorcycle battery can prolong the battery's operating lifetime and avoid future issues due to the battery's inability to crank the engine when required.

Updated: November 6, 2024.

Motorcycle Battery Types

Most popular motorcycle batteries are starting/cranking lead-acid wet/flooded and AGM batteries, with the Gel-Cell batteries also being used as well.

Lithium motorcycle drop-in replacement batteries are not as common and are mostly used in high-end and professional applications.

Lead-acid motorcycle batteries are mostly 12V batteries with capacity ranging from 5-6 to 20+ Ah.

Although these batteries are much smaller than larger deep-cycle batteries, since they are designed and optimized for one purpose, to crank gas and diesel engines, these batteries are able to provide very strong currents.

How long does it take to charge such battery depends on the battery age, Depth of Discharge (DoD%), battery capacity, and similar.

On average, starting batteries may be safely charged with currents that are in the 0.1C - 0.15C range, although some models allow charging with charging currents up to 0.25C - 0.33C.

For example, 20-25 Ah batteries may be safely charged with 2-3A battery chargers.

When charging lead-acid batteries, it is highly recommended to go for a smart AGM battery charger that features battery modes for wet/flooded, AGM, and Gel-Cell batteries, since all these battery types have very similar, but different charging end voltages.

Also, temperature compensation is a must-have feature in order to prevent the charger from under- and over-charging the batteries.

Smart battery chargers analyze the lead-acid batteries first and charge the battery according to its condition - if required, desulphation and deep-discharge recovery modes are used as well.

And when the battery is fully recharged, smart AGM battery chargers switch to the maintenance mode, keeping the battery fully charged over a longer period of time.

The following comparison table lists charging times of the fully discharged (100% DoD - not recommended condition, but it may happen) motorcycle batteries using different AGM battery chargers:

Note: these are just average values that depend on things like battery condition, battery DoD%, battery age, temperature, etc. Also, values with "-" mean that the battery is not recommended at all, while values like "(5-5.5h)" mean that the battery may be recharged, but perhaps the battery charger is a little bit too strong. Anyway, if You can find and check the battery documentation and find the maximum allowed charging current, then You can more accurately determine the maximum charging current of the battery charger.

As one can see in the chart, if You are looking for a good motorcycle lead-acid battery charger, a 2.0 Amps smart AGM battery charger (Amazon link, opens in the new window) is probably your best bet.

Lithium motorcycle batteries should be recharged only using lithium battery chargers or smart AGM battery chargers that feature dedicated lithium battery charging modes.

Depending on the battery design, lithium starting motorcycle batteries may be recharged with currents that are in the 0.2C - 1.0C range.

Again, this depends on the battery model, so please check your battery documentation for the proper charging current.

Note: Lithium batteries are charged using the so-called CC/CV (Constant Current/Constant Voltage) algorithm, which differs from the lead-acid battery charging algorithm.

The following comparison table lists the charging times of the fully discharged lithium motorcycle batteries using different lithium battery chargers:

Note: again, these are just average charging times that depend on many things. Also, values with "-" or "(1.5-2h)" mean that the battery may be recharged with such current, but perhaps the battery charger is a little bit too strong.

Anyway, it is highly recommended when charging the lithium batteries to find the battery documentation and check the maximum allowed charging current - lithium batteries are usually protected via an internal Battery Management System (BMS) that doesn't allow a charging current that is too strong.

As one can see in the table, if You are looking for a good motorcycle dedicated lithium battery charger, a 3.0 Amps smart lithium battery charger (Amazon link, opens in the new window) is probably your best bet, but first, check your battery and its maximum charging current value!

How long to charge the motorcycle battery at 2 Amps?

2 Amps current is suitable for 8-10+ Ah AGM and 4-6+ Ah lithium batteries.

For example, if you have a 12Ah 12V AGM battery discharged down to 50% DoD (6Ah "missing"), a 2 Amps charger can recharge such battery in 3-3.5h, depending on the battery condition.

And if a 6Ah 12V lithium battery is discharged down to 50% DoD (3Ah "missing"), a 2 Amps charger can recharge such battery in 1.5-2h.

If you have a 12+Ah 12V lithium battery, feel free to charge it using a stronger battery charger.

How long to charge the motorcycle battery at 6 Amps?

Not many AGM motorcycle batteries allow a charging current of 6A, but if you have a 25-30Ah AGM battery, charging it with 6A from time to time, without overheating the battery is possible. Larger AGM batteries can be recharged with 6A with no issues.

So, a 30Ah 12V AGM battery discharged down to 50% DoD (15Ah "missing") can be fully recharged with 6A in ~3h.

On the other hand, many lithium batteries feature a maximum charging current of 1C. However, to stay on the safe side, consider using 0.3-0.5C currents for charging your lithium motorcycle batteries.

So, 12Ah or larger lithium motorcycle batteries can be recharged using 6A.

For example, an 18Ah 12V lithium motorcycle battery discharged down to 50% DoD (9Ah "missing") can be safely recharged in ~1.5h using a 6A charging current.

Note: always check the documentation that came with your lithium battery, just to be sure.

Long Story Short: If You ride your motorcycle regularly and everything is alright with its electric system, it is very hard for the battery to get so discharged that it is unable to crank the engine.

In that case, check the battery type and capacity, get a suitable charger, and recharge the battery - in most cases, the battery is still good to go for many miles.

But, if the smart battery charger signals "bad battery", perhaps it is time to go for a good Powersports Battery and to replace your current battery.

Note: although these batteries are small, they are able to provide rather strong currents - so, safety first!