December 12, 2012

For most of the US, winter has arrived with just enough cold to bring a halt to the riding season. Hopefully, most of you reading this post are taking the time to prepare your motorcycle for storage.

While there are a number of things that should be done to a motorcycle for winter storage, at Full Spectrum Power we are mostly concerned with how you handle your lithium battery. There is a proper way to care for your lightweight battery, and we are going to discuss that here.

We are also going to talk about a lot of the misinformation being passed off as correct by other battery companies. We cover this information on our FAQ pages and our video page, so if you want to learn more, head over and start reading.

There are two ways that you can store a lightweight lithium battery properly:

1. Disconnect it from the bike. Lithium has a very low self-discharge rate and will be able to sit for months on end without losing charge, provided it isnt connected to your vehicle. You dont need to remove it completely, just disconnect one of the battery cables, preferably the negative cable.

2. Use a maintenance charger specifically designed for lithium batteries, like our Pacemaker charger. We would actually prefer you to disconnect your battery if you dont plan on riding for longer than a few weeks. Maintenance chargers are great to keep the battery from being drained by the clock, alarm, ECU and other accessories, but leaving it like this for an entire winter is the equal to riding your bike for 24/7/365, and will eventually wear out the battery. When it is so easy to disconnect a cable, why would you do anything else?

The question we get asked most often is, “Can I use a Battery Tender® on my lightweight battery?”

Tricky question- Well, yes you can… but no, you should not- at least if you want the battery to survive. The follow-up question is always, “Why not?”.

(Note- we are talking about Battery Tender® brand chargers here, as this is by far the most popular charger in use in the US market.)

Why you should not use a Battery Tender® on a lithium battery

Here is the simple answer: A Battery Tender® can not measure State of Charge (SoC) of a lithium battery. It simply does not have this capability. While they work great on lead acid batteries, they are not able to accurately “read” lithium batteries. So, they will never properly charge a lightweight lithium battery.

Beyond SoC, the Battery Tender® is looking for a 6 cell battery, with each cell having roughly 2 volts. All lithium lightweight batteries are based on 4 cell packs, with each cell having roughly 3.3 volts. This sends the Battery Tender® a reading that is outside of the safe charging window, and contributes to the incompatibility.

So, how will this damage a lithium battery? The answer depends on a number of factors which are too numerous to go into here. The fact is that it wont work properly, it can damage a lightweight lithium battery, and will void your warranty…so dont do it.

A final note- when you see battery companies advertising “no battery tender required” or “works with battery tender”, they are either lying to you, or dont know any better. Neither of those options is good when working with a battery company and should raise a big red flag about their understanding of the products they are selling.

Next week, we are going to discuss another topic related to lightweight battery performance- thanks for reading!