February 18, 2017 • Tim Technical Support Specialist

How do I CHOOSE The Right Battery for my bike?

Welcome to this week’s tech talk at Venom Motor Sports!

Often the “which battery is the right battery for my bike” question comes up. This is not always an easy question to answer. There are many considerations when it comes to making the right choice and this week we are going to work through that process step by step. Of course the default answer is simply “replace the battery with the same rating as the one currently installed”. However, armed with some knowledge you can make a better choice.

To help with your understanding of various battery designs please click on the “battery” videos links below. These will help you understand the different types of batteries and applications they are used in.

Thank you “youtube”!

Keep in mind that this information applies to all of our bikes!

Ok!, on too this week’s topic!

Tim...What is the start point when choosing a new battery?

I like to begin with what is the voltage level you need? Most of the batteries used on our “gas powered” bikes use a 12 Voltage Direct Current Battery, featuring a negative ground.

These batteries are either of a typical lead acid design, sealed lead-acid (SLA) design or absorbed glass mat (AGM) rechargeable battery design. AGM and GEL batteries are lead-acid and of the same battery chemistry. Again typically used on negative ground based systems.

The negative ground is important to mention, as it means that the batteries negative terminal is connected to the frame. This means that all of the frame is now negative.

Negative grounding is an important consideration when adding things like cool auxiliary lighting to your bike.

Your bike frame already carries a negative charge so you need only run a power wire from the battery to any load connected to the frame. For example...your left turn signal light is already grounded to the frame...which means that you only have to run a single “hot wire” from the positive side of the battery through a switch to make the light come on. See how handy this is, instead of having to run two wires to the light...you only need to run one “hot” positive wire to the load, usually “Red” in colour.

Grounded wires connecting a load to the frame are typically Green. The main ground wire from the battery to the frame is “Black” in colour.

Tim...Does the above negative frame wiring system ever charge?

Yes it does!

Our electric ATV’s use a 36 VDC system. These types of electrical systems do not use the frame for grounding purposes. So each light or load has both a red and black wire running to it...typically from the “speed controller” which is the brains of the electrical system.

Electric ATV’s feature forward and reverse motion. This is usually achieved by reversing current flow to the motor....in other words switching the red wire to the black..and the black wire to the red position. Amazing really! Switch the power supply around and the ATV can now go backwards. No need to worry about this...as the fancy forward/Reverse switch found on the ATV does all the work for you. You just click forward to click backwards.

Our electric dirt bikes which use 24 VDC are also wired in a similar manner....except they do not go backwards. Can you imagine an electric dirt bike that could run backwards? LOL fun!

Tim...How do we make 24 VDC, 36 VDC or 72 VDC batteries?

Well, this is where things get a little complicated.

If you have ever given a car a boost or charged up a battery you will be familiar with wiring in “Parallel”. You would have connected the batteries together by placing a red wire from the positive side of the battery...to the positive terminal on the battery being boosted. You would have done the same thing to the black negative terminals. Wiring in Parallel means that the voltage stays the same but the current flow differs. So when you boost or charge your car or bike battery the voltage remains at 12 VC.

If however, we change things up a bit...we can increase the voltage available. Imagine that you have two 12 VDC batteries side by side. First run a wire from the positive terminal of battery A to the negative terminal of battery B. This joins the two batteries together in “Series”. If you then take a voltage reading using your multimeter from the Positive terminal on battery B to the negative terminal on battery A your will read 24 VDC, 24 VDC is commonly used as a voltage for Electric Dirt Bikes.

If you connect three 12 VDC batteries together in Series you will produce 36 VDC which is commonly used for Electric ATV’s. You can go even higher and connect 6, 12VDC batteries in series to produce 72 VDC used on Electric Motorcycles. Amazing!

Tim...What does the term “amp.hr” and cold cranking amps “C.C.A.” mean?

These are both common terms used to describe the energy that a battery has available under different operating conditions.

For example, if your battery has a rating of 5 amp.hr it means that your battery can produce a current flow of 5 amps for one hour without a drop in voltage. Of course this measure is done in perfect conditions on a nice hot sunny day. The colder your battery gets the less current flow it will typically produce. We never drive our bikes in the snow here in Canada so during the winter months our bikes are in the garage.

This is a good thing as the batteries found in bikes do not like cold weather and prefer temps above 10 C. So always store your bike battery indoors during the winter months.

These are the typical specs listed for a bike battery. Most bikes use in the range of 4 or 5 amp hours. Other than that you are next most concerned with the physical size of the battery as it must fit into your existing battery well on your bike.

Specifications

Voltage: 12 Volt

Amperage: 3 AH

Chemistry: SLA, AGM

Dimensions 4.40 in x 2.75 in x 3.42 in

In Canada we store our bikes in the winter...lol and take out our ATV’s which are designed to start up on cold winter days. The reason that our ATV’s are able to start up on the cold winter months is that they use a different battery design than “summer only” batteries. The C.C.A. rating for a battery is the “Cold Cranking Amp” rating for a battery. The higher the C.C.A. rating the better the battery will be able to perform in cold conditions.

Specifications

Voltage: 12 Volts

Capacity: 12 Ah

C.C.A.: 180

Dimensions: 151mm x 87mm x 146mm

Tim...Have you found any good video’s on Batteries?

Yes! gotta love “youtube”, thank you fellow “youtubers” for sharing your videos.

The video’s listed below are some of my favorites. Just click on the link below!

Battery Basics & Activation - Filling & Charging A Motorcycle Battery

https://www.youtube.com/watch?v=LUrZmKbkMz8

Motorcycle Battery Maintenance - How to Extend the Life of Your Battery

https://www.youtube.com/watch?v=siyR4l3eVlo