The Voltage Conundrum: Is a Surron Better with a 60V or 72V Battery?

60V vs 72V Battery

Have you noticed many e-moto riders upgrade to a 72 Volt battery? Let’s discuss if a 60V or a 72V battery is better for your riding style and, more importantly, how to know you’re actually upgrading to something better. 

However, before working out what battery you need, we need to have just a little understanding of a few basic principles. It’s not quite as simple as comparing *this* 60v battery with *this* 60v battery… there are many variables to consider. 

Batteries are an in-depth topic, of which I’ll only cover the basics as I’m not a battery builder or manufacturer, just someone who has learned the basics, and asks experts many questions! This discussion will be limited to how batteries affect your Surron LBX without taking into account all variables, though the information this guide covers generally applies to all suitable e-motos like the Talaria Sting and E-Ride Pro SS.

Why Upgrade Your Battery?

You need to be clear on why you’re upgrading before starting the modding process. Is it for range? Higher top speed? More torque? Commuting will have different requirements to MX tracks, unless you’re scrubbing the jumps and riding the berms on the way to the office. If so, I think you have a dream job! (or at least dream commute!)

Rules of Thumb when Choosing your Surron Battery

• More Range: Look for a higher Amp hour rating 
• More Torque: Look for higher Amps
• Higher Top Speed: Look for a higher Voltage

Starting The Upgrade Process

Before starting any mods on the powertrain, you’ll need to work out if you choose a 60V or 72V battery. This will change many factors in your modding process. If you upgrade to a 72V battery, and have a stock controller and motor, you’ll need to factor in upgrading these components also. The 60V option means you‘ll be able to upgrade in sections and use the stock controller first, even if it’s not using the battery to its full potential. Yet.

Most of these modifications can be done at home, with limited experience, but you will always need to check if you need to upgrade the wiring loom, circuit breaker, etc. The battery manufacturer will be able to assist with what else will need to be upgraded. Always ask if you’re not sure, and don’t be afraid to take your bike to one of the growing number of independent shops out there willing to do your entire 72v upgrade so you don’t have to get your hands dirty. 

When you start to dive a little deeper, you’ll see there’s lots more to it than a few simple numbers – what happens if the battery manufacturer doesn’t have comparable data? We need to make sure we’re comparing equivalent data. This is when we need to grab a calculator and find the right numbers to compare.

Watch the video here:

Important Battery Terminology 

Please note: the following equations are accurate, but don’t account for many variables that are outside the scope of this article. You may find some discrepancies when using these equations compared to manufacturer data – which often accounts for many variables. These equations are, however, the best way to gauge battery capacity. 

Let’s kick off the tech talk with a recap on the terminology – take note of how components are related. 

• Cell: An individual component within the battery housing that undergoes a chemical reaction to expel energy as electricity. When joined up in series, they create the battery. 
• BMS: Battery Management System. The brains of the battery. It is an integral part that looks after the battery – it determines things like safety control, if power output needs to be lowered to preserve the life of the battery. It also won’t let the battery go below a certain level or overcharge when it is full on the charger, and many more things.
• IMPORTANT EQUATION: Watts = Amps x Voltage (remember this one or write it on a sticky note!) 
• Watts: A Watt is how you measure the power. You can work out Watts by calculating Amps x Volts. 
• Amps: Amps are how you measure how big the stream of electricity is. It is how much current is flowing through your electrical circuit. Think of the water inside a large-diameter hose vs. a small-diameter hose. 
• Voltage: Voltage is a term that describes how much ‘pressure’ pushes electricity. Higher voltages ‘push’ more electricity flow into an electronic device. Think of electricity as a stream. It will flow from a place of higher pressure to a place of lower pressure, much like a stream flowing from the top of a mountain to the bottom. You could replace the word flow with ‘current’ and voltage could be the potential energy ‘pushing’ it downstream.
• Amp hours: Measures how many amps can flow in one unit of time. It is a simple way of measuring how ‘big’ the battery is. (Think: how much gas is in your tank)
• Watt hours: Calculated as Volts x Amp hours = Watt hours. It is a measurement of the equivalent usage of 1 watt of energy per hour.

What Battery Does a Stock Surron LBX Have?

With a little background knowledge, and a handy calculator, we can start looking at comparing batteries in real life. Taken directly from Surron’s website, the battery details are: 

• 60V 40Ah Lithium Battery
• It also mentions 6kW peak power and rated at 3kW

Thinking back to the equation Watts hours = Amp hours x Volts. We can calculate 40Ah x 60V= 2400 Wh, meaning you could draw 2400 W over one hour or spread it out over many hours (theoretically). If you’re running at the rated 3kW, you’ll be drawing 50 amps (W/V=A or 3000W / 60V = 50A). Now, let’s say you bypass the battery BMS and ask the battery to deliver, say, 7kW. This means that you’ll be drawing 116 amps. (W/V=A or 7000W / 60V = 116A) Generally, higher amperage means less efficiency and more heat generated.

Now, you’re starting to have some comparable data to start making comparisons with other batteries. 

72V 40Ah Lithium Battery comparison to the Stock Surron LBX 60V 40Ah Battery

To keep things simple, let’s compare a hypothetical 72V 40Ah Battery. (Note I’ve kept the Amps constant for this example). So, this battery in Watt hours would be 72V x 40Ah = 2880 Watt hours. Already, you can see that this battery has a higher Watt hours. This gives a good indication of a potentially higher range. If you use the same tune of 7kW, you’ll need only 97 amps (W/V=A or 7000W/72V = 97A). This is more efficient than the 60V battery due to lower amps (lower current running through the circuit). 

This is where things start to get a little more complicated. 

What Happens When the Amp Hour is Different? 

Now for a real-life example with Chi batteries. These figures are taken from the Chi Battery Systems website covering three different batteries:

• Gladiator 60 Compact: 60V 51Ah. This will produce 2938 Watt hours. Yes, much of the time you’ll actually need to grab your calculator to make the comparisons. If you were to keep your stock controller, and run a 7Kw tune, then it would be drawing 50 amps. Taking nothing else into consideration, comparing this battery to the 60V 40Ah stock battery, the amps would be the same but this one would give you a greater range. Of course, in the real world we need to consider things like how they are made, how efficient the battery is, the BMS and more, but without overcomplicating this article (for now), the higher Amp hour rating of the Chi would, in theory, give you a better range. 
• Gladiator 72 Max: 72V 51Ah. This gives 3672 Watt hours. So, again, even more range than the previous example. Now, if you kept the same 7Kw tune, then it would be drawing the same 116 amps. So, in this example the Watt hours measurement is greater. But if you were to compare the Gladiator 60 70Ah battery, the Watt hours are 4200 Watt hours – so, look at the Gladiator 72 Max Watt hours. See that it is greater? This battery has a larger range. Keeping to the 7kW tune, the 60V battery will draw 116 amps. Lost yet?
• Gladiator 72 Touring: 72V 60Ah. Watt hours are 4320 Watt hours. On the 7kW tune, 97 amps would be drawn. So this battery would, in theory, have a larger range and a greater efficiency that the 60V batteries – hence the “touring” name.

Let’s simplify all of this information. If you multiply the volts by the amp hours, you’ll get watt hours. This is an indication of potential range. Hence, a 60V battery with a higher Ah rating might have a larger range. However, you need to consider amps. The lower the amps, generally the better efficiency. The 72V batteries will generally have lower amps. So much for simplifying things! 

Peak Power Output – What is the Importance of This? 

Manufacturers discuss peak power output like it’s the next best thing. Surron exclaims on their website that their e-moto has a peak output of 6Kw. While this is a somewhat useful figure for comparisons, it doesn’t tell you much about everyday riding. On the stock setup, you may be able to hit this output, but not keep it sustained. The BMS won’t allow that. Think of it as ‘redlining’ your engine. Gas powered car companies don’t go around telling you redline figures as part of their marketing strategy, but I digress.

Controllers

The next topic of discussion needs to be: why keep only a 7kW tune? If you have a beefier battery and you’re like me, you’ll want more power! The reason to keep to a lower kilowatt tune is due to the limitations of the stock controller. If you want to get the most out of your bigger battery, you’ll need to consider upgrading the controller. Read more on controllers here. Not to mention, the stock controller won’t be able to talk to a 72V battery and you will require an aftermarket controller. Once your controller can safely handle the larger input, you will also need to look at upgrading your motor to be able to take full advantage of all your new power. 

On your wish list, let’s say you install the EBMX V2 X9000 Controller, which is capable of tunes up to 40kW. If you have a 60V battery, you’ll hypothetically be drawing 666 amps, whereas the 72V battery will be at 555 amps. The higher power is when you need to start really watching your amperage. Remember, higher amps means less efficiency, and will expel more heat. This, of course, is theoretical as the Chi batteries recommend the highest continuous amps of 30 amps on their 72 Max battery. 

What are Batteries Made of?

Without going into in-depth detail that’s beyond my understanding, something that does need to be considered are the materials the battery is made from and the build quality. You’ve probably noticed that comparable batteries (ie same voltage and amperage) vary considerably in price. That’s because, you guessed it, build quality varies. 

There are two distinct ways batteries can be made. Either by connecting multiple cells, think of your standard torch batteries, or pouches which are similar to your cell phone battery. Generally speaking, the cell style batteries can withstand more amps and are more efficient. However, being cylindrical, the cells don’t pack as nicely together as pouches. This can make the battery bigger and not as customizable. On the other hand, pouch cells can be tightly packed together, but in turn, this creates more heat buildup – reducing efficiency. 

Then you need to look at the quality of the cells themselves, and the packing and build quality. You don’t need to be a battery buff, just be aware that there are different types of cells, packing materials and battery housing. This resource will give you an understanding of why the price varies, and why buying from a reputable store might just save you long term costs. It would also be worthwhile reading this article about battery care and the importance of buying from a reputable brand.

What is the Best Battery For Me?

This needs a two part answer. The first is how much are you willing to spend? A larger battery doesn’t just mean more cost in the battery – you’ll also need to look to upgrade other components to utilize the full power of your new battery. Don’t forget about physical size too! We’ll get to that in a moment.

The second part is, what is your riding style? If it’s commuting to work, you probably don’t need the highest capacity battery unless you’re pushing the distance and need something that will last a long time. High torque probably isn’t necessary either. If you’re after high bursts of torque on the motocross track, then the 72V battery could be what you need. 

The 72V battery would, in theory, have a higher top speed, however usually the motor has an RPM limiter and this would be the deciding factor in top speed.

What Order Do You Need To Upgrade Parts In? 

Think of your Sur Ron’s drive train as the controller, motor, and battery. Read more on controllers here. The brief run down is: If you want a 72V battery, you’ll need a controller that will be able to talk to a 72V battery. The controller will also need to be able to handle the power of a larger capacity battery.  Likewise with the motor. 

Sticking with the 60V battery will allow you to upgrade the motor and controller at a later date. Just be cautious of how big you make the tune, and how hard you’re trying to get the stock motor and controller to work. They have limitations even though your battery might be able to handle it, and you could risk damaging those components. 

Physical Size

Bigger batteries may just not fit into the stock compartment! For this reason, if you’re after bigger capacity, the battery itself might come with additional covers or base plates. It will also be heavier. Some upgraded batteries are able to fit into the stock battery holder, and some will be protruding from the top! This may make the concept of ‘plug and play’ a little more difficult, and will require knowledge of changing the top cover, wiring loom, circuit breakers, etc. If you’re not sure, chat with the battery manufacturer or give us a call to talk with an expert.

Something else to consider is the weight. Between the Chi batteries, you’ll be looking at 33lbs to 44lbs. This is a big difference to a light e-moto like a Surron LBX. If you’re running higher amps, you may also need to increase the size of the wiring loom, which again might add more weight – a small amount, yes, but it all adds up with a bike this light.

Charger

Just a point to note, if you purchase a new battery, be aware that unless it says otherwise, you’ll probably need to also purchase a new, separate charger, especially if you upgrade to the 72V battery.

Surron LBX 60V vs 72V: The Final Verdict

Unbelievably, after all that, 60V vs 72V battery is still questionable. Which battery do you upgrade to? The questions that really need to be asked are:

• Do you need to upgrade?
• What is your riding style?
• Are you commuting a short distance and don’t require crazy acceleration or range?
• Perhaps the stock battery will be sufficient for your needs, and instead, look at upgrading something else to make your ride better suited for your style?

If there’s one thing I hope this article helps people avoid, it’s going out and getting a 72V setup just because it’s a bigger number than 60! To be clear, you definitely don’t need to spend a ton of time or money on a fancy 72V setup just to have fun on a Surron LBX. Our staff has ridden bone-stock LBXs in sanctioned off-road competitions, and even in a grueling setting like that we still had plenty of capability to work with. For riding on the road or having fun around town with friends, there’s nothing wrong with the stock battery at all.

But, if you’re like the majority of riders who want faster everything… you won’t go wrong with the 72V battery. Just factor in the price of an upgraded controller, motor and potentially wiring loom so you don’t get any nasty money-related surprises. Read what comes with your battery to ensure you have all the parts ready, including the charger. Follow the manufacturer’s instructions, or ask if you’re not sure. Whichever option you choose, you know you’ll have great fun on your e-moto, and when the time is right, head to GritShift to stock up on all the accessories you need to finish your upgrade.