January 28, 2019

We'll discuss the basic technical requirements for putting a lithium battery in a bike. Lithium motorcycle batteries are not particularly complex, and as a result the technical requirements are pretty simple. 

While we would love to see a lithium battery in every motorcycle on earth, the truth is that not every bike, and not every rider, are good matches to lithium batteries.

We believe that our Pulse IPT batteries are a great replacement for lead acid batteries in almost every scenario- Lighter, stronger, longer lasting, with built in protection from damage are all reasons to choose lithium. There are a few things that need to work in order to use a lithium battery in your motorcycle.

So- Is your bike a good candidate for a lithium battery? What makes a bike a good candidate? Is your riding style a factor? How about climate? Will a lithium battery work in an older motorcycle? There are a few considerations to take into account: physical fitment, charging system health, and intended use are the three main things to understand here.

Let's look at fitment- we will have something for your application. This is one of the sticker racks for Pulse IPT stickers.

Pulse IPT ID Stickers

We have worked very hard to create a massive variety of sizes and power levels for our Pulse IPT battery line. At the moment, 14 individual sizes and more than 40 combinations of power and size are available. There are a few ways to size your battery correctly.

1. Use our Battery Finder Tool on our website. This is a good way to get the correct size and power to replace your stock battery.

2. Use our Battery Application Guide Document to find the physical size that fits your bike, and then choose the power level you need. So, if you have increased the bore, stroke, and compression ratio of your engine, you would want to try this method of battery selection.

3. Send us an email or call us for advice. All we do here is design and build batteries, so we have a very good idea of what will work- even if you have a really wild combination.

Now, let's turn to charging system health. This is the single most important factor in using a lithium battery in a motorcycle. 

First, all motorcycles built since 1980 are capable of running a lithium battery, providing they are in *good working condition*. More specifically, the charging system on your bike *must charge between 13.4v and 14.6v*. Every motorcycle in good working order should meet this requirement. If your charging system only puts out power under 13.4v, the battery will never charge. If it is over 14.6v, it means that your regulator is about to fail, and would likely trigger the over voltage protection in the Pulse IPT. In either scenario, this means that your bike is not suitable for a lithium battery. It also means that you have a problem that is going to damage whatever battery you are currently using, and will not be fixed by getting a new battery. 

Unfortunately, many motorcycles do not have properly functioning charging systems. In fact, during a recent restoration of a 1999 R1 here at the shop, we found that the charging system was operating between 12v and 12.8v. The cause? The regulator/rectifier was failing. So, we replaced it with a modern MOSFET regulator and it now charges at 14v. We dont sell regulators, but we are happy to point you in the right direction- send us an email. Further, we are happy to help you test your charging system. All you will need is a digital multi-meter and a phone- call us and we will help you figure it out.

Here is a Shindengen MOSFET regulator install on a Ducati 999s. This turned a troubled charging system, into one of total reliability.

MOSFET regulator installed on Ducati 999

Does your riding style have any bearing on using a lithium battery? Not if your charging system is actually working, no.

How about climate? Climate could have an impact on use of lithium. This is more complicated than a simple yes/no.

The operating temp range for our lithium batteries is -20f to 150f. So, unless you are riding on the moon, there shouldnt be an issue. There are some things to be aware of, like how lithium batteries behave in cold weather.

We have lots of friends that use our batteries ice racing, or in snowmobiles, in very cold temps. We also hear people complain that lithium wont work below 40f- so what gives? How can both of these be true?

Well, here is the deal: lithium does not like to be used to start engines after being cold-soaked for a few days. For example- if you leave your bike in an unheated garage in sub-freezing temps, dont expect to turn the key, and have a quick start when you hit the start button. Because the electrolyte in the cells is basically frozen, it is going to need a little bit of help to wake up. There are a few ways to deal with this:

1. Connect a charger for 30 seconds. This will bring the battery to within its optimal operating window very quickly.

2. Turn on lights of accessories. Creating a load on the battery forces the battery to 'wake up'. It might take 2-3 minutes for this to work, depending on the bike. Using the horn button is also a great way to load the battery.

3. We do not recommend hitting the start button repeatedly. While this may work, it also has the potential of damaging the starter gears or sprag, and should not be considered a good solution.

Now, if you are keeping your bike or sled in a heated garage or trailer, you will have no problem with starts. Riding in the cold is very different from starting in the cold.

Bottom line on climate- if you ride in very cold weather, and it is really crucial that you be able to start your bike in 1-2 seconds, lithium may not be the best choice.

If there is one takeaway from this post- one thing that you really need to understand here it is this: your charging system must be in excellent working condition in order to use a lithium battery. This is not only true of our Pulse IPT batteries- this is true with all lithium batteries. I hope this has been helpful.