Motorcycle Lithium Batteries: All You Need to Know

Lithium batteries for motorcycles are a matter of heated debate amongst mechanics and motorbike owners. The short truth is that these power cells have both pros and cons. Even good ol` lead-acid batteries aren’t perfect, so it’s not a reason to avoid buying a motorcycle lithium battery. Still, you have to learn more about them before it. This guide by YourMotoBro.com moto lovers will help you a lot.

Cranking Power & Weight

That’s where Lithium batteries always win. For example, a Motobatt MB16U weighs a bit more than 11lbs and makes 200 Cold Cranking Amps. A lithium Ultrabatt battery weighs only 2.2lbs and grants your bike 220 CCA. Isn’t it an incredible result for such a small part? Racing batteries can be even smaller than that for extra weight reduction.

Charge Times

A good LiFePO4 battery with a BMS (read further for details) will charge up much faster than any other unit. It usually takes around 5-7 minutes to restore the power that was consumed to start the bike. If the battery drains out to the point where it can’t power the starter anymore, you can turn it back to the full capacity within 1-2 hours, depending on its size. Well, conventional lead-acid batteries need up to 12 hours to get full.

Self-Discharge Rates

You probably know that many riders install smart battery chargers on their lead-acid batteries in order to maintain them and keep the self-discharge rate as low as possible. The problem is that these devices cost like a second battery, which isn’t nice for anyone’s budget. Lithium batteries don’t suffer from that ‘disease’ and can stay idle for around 5-6 months keeping the charge high enough to start a motorbike. This means you won’t need to spend money on a smart charger.

Service Life

According to user polls by different brands, most of the lead-acid motorcycle batteries last from 3 to 5 years, while over 21% of all batteries die within the first 2 years. That’s quite a high failure rate. The ‘death rate’ for lithium batteries is as low as 2% for the first 2 years of use. This means that the chances your new LiFePO4 battery dies young are 2:100 against lead-acid’s 21:100. That’s an immense difference.

BMS and Overcharging

Although lithium batteries aren’t too new for the market, some manufacturers still try to sell the units without a built-in BMS to inexperienced riders. Battery Management Systems are essential for LiFePO4 units as they keep the cells charged evenly and keep the lifespan long enough (5-10 years). Without a BMS, the cells may overcharge or undercharge, which causes disbalance within the battery and leads to faster wear-off. Such batteries usually stop working after 2-3 years and hardly survive 5 years if you get an external BMS. Don’t waste time and money and buy batteries only if they have this protective layer.

You should also avoid manufacturers that separate the cells within the battery as it leads to battery bricking, which means you won’t be able to recharge it after 1.5-2 years of use. Together with BMS absence, this will also lead to poor performance in low temperatures, destructive overheating if short-circuited, and quick capacity reduction of the cells.

Size

The rule of thumb is to get a lithium battery that matches or exceeds the CCA of your old unit. YourMotoBro.com experts recommend installing universal batteries with universal PCA (Pulse Cranking Amps) to match both cold and warm weather conditions. You need:

  • 120 PCA for 125-250cc road bikes and 600cc race bikes with a starter;
  • 240 PCA for 600-1000cc;
  • 360 PCA for 1000-1400cc.

Power Up

As you see, there’s nothing to worry about with a lithium battery if you know how to choose it properly. Units with BMS don’t require extra maintenance and provide excellent reliability. It’s a modern lightweight option that will serve up to 5-10 years if you get the right one.