One bar remaining.
If you’re saying it’s not “safe” to keep riding the board at one bar left when I get the buzz notification then I would’ve liked to have known this since with one bar left I’m not even close to the advertised range. This is something customers should know.
“Safe” can mean alot of different things. I’m talking about maximizing the life expectancy of your battery.
I’m saying your battery will last longer and have better range if you do not ignore the warnings that tell you have just dropped below critical voltage. I’m saying that if you repeatedly ignore the vibration alerts that there is a very high probablility of battery damage and reduced range.
I’m just another customer like you. I’m not speakng on behalf of any manufacturer or about any particular manufacturer. I would give you the same advice if you were riding a boosted board, or an evolve, etc.
Lithium batteries are not intended to be fully depleted. I own a Nissan Leaf electric car. When my range drops to 30 kilometers I start getting warnings. At 20 kilometers of range the car won’t stop beeping. Those warnings are there to prevent me from damaging my battery.
Lets talk about the Nissan Leaf range. If I drive at residential street speeds, then I can get approxmately the advertised range. If I travel on the highway at 120 kph, I get half the advertised range. If the weather is cold, the range drops by about 30% or more. If I accellerate hard, I don’t get to drive as far.
These are characteristics of lithium batteries/EV’s. No manufacturer guarantees you a specific range regardless of temperature, acceleration and speed.
It sounds like you can get approximately the advertised Revel Kit range if you ride the Kit until the last drop (and if you ignore at least one vibration alert). It also sounds like you would be disappointed with the range if you stopped at some point on the fourth bar when you feel the first vibration alert.
How far do you get before the first vibration alert? How much further do you get if you ignore the alert.
I’m a heavy rider (220 lbs with gear). When I rode a 2WD Revel Kit, at conservative speed and acceleration, then on a warm day, I could make it to 14 kilometers before a vibration alert. I will admit to just once riding past those alerts in order to stay with a group of riders who had bigger batteries than me. My revel kit powered down at 17 kilometers. The extra three kilometers were slow, stressful and not much fun. I also felt really bad because I knew that I had mistreated my battery.
But I don’t often ride that conservatively so my range is often less. If i ride near top speed and accelerate hard then my range can be as low as 6 kilometers. This variability is normal.
So given my own tastes for acceleration, speed and range, I upgraded to 4WD and a total of four Revel kit batteries. Two extended range and two travel size. Now I’m never tempted to do bad things to the battery. I don’t get stressed about getting stranded.
So think about what your range expectations are and if you should lower them depending on…
How much do you weigh?
How hard do you accelerate?
Do often you travel at higher speeds?
Have you been riding in relatively cold weather?
If there is a gap between the range you need and the range that a revel kit produces for your weight and riding style, then the simple solution is to buy an extra battery. They don’t cost alot and I would be surprised if you did not thoroughly enjoy the freedom of swapping batteries at the first warning. It really is alot more fun than streaching out a charge on eco mode.
For everyonr’s sake I need to inject that you have named 0 facts here. Without knowing the cutoff voltage of the BMS and when the warning comes on, all that means nothing.
Lithium doesn’t like being discharged under 20% and over 80%, most electric cars will limit this to those numbers unless you activate extended range.
Usually this means warning around 3.2v, but most lithium cells do not suffer rapid damage unless discharged under 2.5v per cell. It’s usually suggested not to go under 3-3.2 per cell for longevity sake.
However one first must know what the cutoff is on the BMS. If the bms gives warnings and cuts off at 3.6v per cell, you could squeeze it until the BMS never turns back on and its still good because you barely used half the power before shutoff… If another BMS cuts off at 2v per cell, even if you stop at the first warning, you’ve already fucked the cells because it went way below lithium ion safe voltage…
So unless you can put out numbers and state at what voltage per cell is the revel kit giving warnings and when does it power down, all that speculation means nothing.
And no, not all BMS is the same. Some push safer numbers, some let it go to the last drop, and some is programmable so you can decide when it cuts power.
So most people don’t realize this but the BMS is rarely triggered while opperating an electric skateboard. It is the ESC or VESC that monitors the battery voltage. The ESC/VESC also does the pacing so that acceleration is throttled back when voltage starts to fall. And it is the ESC/VESC that issues all of the low battery warnings to the remote. It is the ESC/VESC that gracefully powers down the skateboard based on the low voltage of the battery.
So everything you just wrote about the BMS is not relevant.
Occasionally, A BMS will (ungracefully and without warning) cut off the power to a skateboard ESC/VESC. These are pretty dangerous events becasue the sudden loss of power can trigger 100% brakes or it can leave the rider with no brakes on a hill.
The events that can trigger a BMS to pull the plug on the ESC/VESC are excessive battery temperature, Excessive voltage (overcharge) or extreme critically low voltage. The latter should not happen with a healthy battery becasue the ESC/VESC should throttle back and power down gracefully long before the BMS critical voltage is reached. But in the case of batteries with damaged cells, the voltage can crash so suddenly that the ESC/VESC has no time to perform that task.
.
Just look at any wiring diagram for connecting a VESC to a battery. The VESC is wired to positive and negative wires of the battery. There is no communication port between the BMS and the VESC. The transmitter is connected to the Vesc, not to the BMS. The BMS has no means of communicating with the VESC or the Remote, or the rider. The only thing a BMS can do is to completely disconnect the battery from the entire system.
In general, a 36 volt electric skateboard battery charges to about 42 volts and I’m pretty sure most ESC/VESC will try to keep the voltage above approximately 38 or 39 volts. When the voltage drops below that you get a critical battery alert. For example, the voltage might drop to 37 volts under load and then recover to 39 volts. That’s enough for the ESC to continue operating but you are operating on a marginal charge (which I recomend against).
Note that the ESC/VESC is monitoring the total voltage coming out of the battery. So if some cells are weaker, the ESC/VESC is oblivious to that fact. By keeping the voltage of the entire battery up around 39 volts you are protecting the weakest cells from the type of damage that can cripple a battery.
Oh shoot, you right. VESC does not run through the BMS… Sorry I missed that on the VESC schematics…
So the Vesc schematics should show the vesc connection to the batter as a simple +/- connection.
Within the battery, most batteries are wired so that the BMS can pull the plug on the wires that exit the battery.
People who build their own custom DIY electric skateboards for climbing and decending large hills often build their batteries with two circuits. The charging circuit runs through the BMS. But the operational circuit to power the VESC and recieve Regen current is direct to the battery.
This apporach is suitable for very large batteries that can accept a high regen flow rate. It eliminates the risk of the BMS pulling the plug on a steep hill.
That sounds dangerous… What protects the battery if the VESC does not go through a BMS?
The BMS protects the battery from overcharging at the wall outlet.
The ESC/VESC protects the battery from excessive discharge.
The battery is unprotected from excessive regen current but there are advantages.
There are two different downhill regenerative current risks:
Overcharged (voltage) due to decending a hill on a full battery. This is never wise but less experienced riders often fall into this trap.
a) If the BMS disconnects the ESC then you have no brakes on a hill.
b) If the BMS can’t disconnect the ESC then you keep your brakes but your battery is likely fried at the bottom of the hill. There are practical limits. There is only so long that you can overcharge a battery before the damage is so severe that you lose your brakes anyway. But this type of wiring can give you a few minutes of lifeline if you are foolish enough to decend a steep slope on a full battery. The battery cells can be destroyed in seconds. But the downhill regen current can keep the VESC powered – which gives you brakes – as long as the damaged battery can still act as a resistor. If the circuit is broken then you finally have no brakes.
Excessive regeneratve current charging rate or high temperature. This can happen on long, steep slopes even when the battery is at a relatively low state of charge. For example if you climb a long steep hill and have 25% battery level on at the top, you may not make it down the same hill if the slope is steep. This happens becasue regen current is much more rapid than the charging bricks. So the down hill regen can be too rapid for a small battery to absorb. However for an extremely large battery there is no risk because the regent current is distributed across so many cells.
a) If the BMS is wired to disconnect the battery, you lose your brakes on a steep slope.
b) If the BMS can’t disconnect the battery and the battery is small then you have a bit more time to brake but eventually the battery may pop.
c) If the BMS can’t disconnect the ESC and the battery is very large then there is no risk of damage and you keep your brakes.
Between the two methods, I prefer bypassing the BMS for operation. I would rather fry a battery than find myself in a down hill free fall.
This is another area where the eskate manufacturers tell you alot less than is known by some customers. I was pretty oblivious to everything in this particular post until I went riding with friends on Mont Royal (Royal Mountain). The local riders with custom build boards and Lacroix had no problem decending. I also had no problem with my quadrupal battery L3-x. But my friend (riding a Mellow Board) lost power shortly after leaving the top of the hill. He lost it at 55 kph and broke his femur. He lost power with less than 50% charge so presumably battery temperature triggered the BMS to pull the plug on the Mellow board ESC.
Incidentally, the L3-x was factory wired to the battery in the same manner as the mountain climbing boards. The L3-x BMS cannot disconnect the power to the ESC. That wireing and the four batteries both contributed to my safe decent. If I had tried to decend that hill on only a single battery I would have likely fried the battery but I probably would have made it to the bottom without losing brakes.
Here is a recap of why it is better to purchase an additional battery compared to riding past the critical battery warnings.
A well engineered electric skateboard will warn the rider and power down gracefully well before the BMS could pull the plug on the ESC. Pulling the plug on the ESC is dangerous for a variety of reasons including no brakes or surprise brakes. So a quality eskate like a boosted board or Revel kit will throttle back power to maintain a voltage that protects the rider and the battery. These qualty systems also issue critical battery warnings and eventually reduce power to bring the rider to a stop.
The Revel kit has a few added safety features. It maintains the ability to brake, even when the battery is too low to support throttle. Not many products do that, I’m not sure if the boosted boards even do that.
The critical battery warnings are issued by the remote when the ESC detects total battery voltage that falls below a threashold. The ESC’s in electric skateboards do not monitor each cell in the battery and there is no communication between the BMS and the ESC. Therefore, the critical voltage threashold of the ESC needs to be high enough that the weakest cell in the battery is protected. If you don’t protect the weakest cell, there is the risk that the BMS will act independently to pull the plug – endangering the rider.
So a well engineered product like the revel kit, boosted board, etc,-- these products are set-up to make your batteries last for years. If you ignore the critical battery warnings then this is potentially problematic. When the load is removed from the cells, the voltage recovers.
In my experience, repeatedly ignoring critical battery warnings can damage the weakest cells in a battery resulting in a very low range or completely unusable battery.
I don’t know exactly why that happens but I suspect that the weakest cells in the battery do not recover voltage as efficiently as the stronger cells. So my theory is that as you keep squeezing out power and waiting for voltage to recover, the weakest cells are being driven down to the level that causes damage.
I think it is a reasonable theory based on practical experience. Here is some of that experience
In Ottawa, we have a riding group and from time to time riders post about having to replace thier batteries prematurely. I ask those riders questions and find that most of them ignore battery warnings and ride until they stop. Those examples include some of the least expensive and some of the most expensive brands.
For a long time, I participated L3-x owner threads. The riders who bought only one battery and tried to squeeze every drop out of thier battery damaged thier batteries. The riders who purchased multiple batteries and respected the vibration alerts are still running strong on four year old L3-x batteries.
And finally there is also my chainsaw battery. An ego battery is a high quality battery that uses the same cells as skateboard batteries. Pleanty of onewheel owners use Ego batteries to supliment Onewheel range or even to replace a damaged one-wheel battery. So the fact that I was able to destroy that brand new EGO battery in the space of five minutes, is some pretty strong evidence that ignoring critical battery warnings is bad for batteries.
So if the way you like to ride does not give you the range that you need out of a single Revel kit battery, my advice is to purchase a second battery instead of riding past the critical battery warnings.
Your battery should last longer, maintain its range. And I suspect you will really enjoy the experience of riding your entire journey on a strong battery.
Hey @BearBoi
You and I both know that the Revel kit batteries are water resistant, not water proof. The same is true of most brands including boostedboards, etc. Don’t get me wrong, I’m not scolding you. I just have a little tip for you to help you protect your batteries when you just can’t resist heading out on salty or damp roads.
I usually wait until the April downpours have washed the roads clean. I wait to protect my entire skateboard including the bearings in the wheels and motors from salt and rust.
I went out a bit early this year so I came up with a 99 cent solution to protect the batteries.
That is a shower cap. Six for 99 cents at the dollar store.
It is very effective at shielding the seam between the battery and the drive against moisture and dust. They also seem to stay on just fine at higher speeds.
It won’t protect my bearings from salt grit but it seems pretty effective for the battery.
I don’t plan to run with these 100% of the time but I do plan to keep a set in my pockets incase i get caught in some surprise rain.
Very much so, I know they are not water proof (none are really).
Nice 
I ordered two new batteries right before the port of shanghai was closed down (bad timing) but should get them in the coming week(s). Hopefully I am not in quarantine when they arrive.
The shower cap is a nice trick. Like you said, not a year 'round always on solution, but in case of emergency. I never go out riding if I know it’s wet or raining, but damp roads and I have been caught by puddles and surprise rain.
Just ordered a pair of 4 shower caps for a total of 1,98 USD shipped to me within Sweden 
could be here as early as tomorrow.
right out of trampas playbook
Speaking of batteries and range, I just wanted to remind everyone that the first few rides of the season after taking an eskate out of winter mothballs can give you much less range than the previous season. For me it usually takes about six charge cycles to get back to normal range. That’s for all of my esk8’s including boostedboad, Onewheel, L3-x and likely also for the Revel Kit.
So don’t panic. The first ride in particular can really short change you on range.
The same is true of freshly unboxed batteries. Over the first six charge cycles, range should improve (provided you are not overdepleting the batteries).
Depeding on where you live, it may still be relatively cool out. The temperature combined with “out of practice batteries” could give you much less range that you will be getting mid-summer.
@jxslepton & @murdomeek
Does this apply to you? Cool Temperatures and/or you bateries are brand new and/or your battereis have been stored all winter?
are there plans to make adapters for AT wheels in the works? The 4wd Revel Kit with extended range batteries is an absolute beast and i’d love to gain the ability to cut across grass and dirt without thinking about it. in the meantime i’m taking advantage of the completely empty golf course nearby with beautifully pave golf cart paths
PS: would not be going AT on the golf course, that would be a garbage thing to do
@visnu777 has built a 4WD AT direct drive setup that may be relevant to your question.
I’m not sure if he built it with standard TB wheels and Elofty drive adapters. It is also possible that he has made some custom parts.
@visnu777 can you enlighten us?
Here are two links to his creation.
@visnu777
I did 60 seconds of research and it looks like the e-lofty motors have 5 bolts vs 4 bolts on the Revel Kit. the TB dd motors have 6 bolts. So neither the E-lofty or TB wheel adapters would fit a Revel kit motor.
Also, the 160mm TB wheel has a new five spoke pattern that would not fit Kegel or ABEC motor adapters.
So it might be possible to mill down the TB gear pulley for the 160mm wheel, drill 4 holes and convert them into DD wheel adapters.
The alternative would be the Janux aluminum rims. see next post.
Is there any reason that these would not fit on a Revel Kit Direct Drive.
Is it correct to assume that your Kegel version is standard Kegel and ABEC is standard ABEC. Correct?
and the bearing spacing is standard right? So it won’t require any additional axle length compared to standard urethane wheels?
Do you also sell the tires? If not do you have a tire ordering link?
The TB direct drive is not recommended for AT wheels if you’re not in 4WD… The revel kit is less powerful than the TB… So no chance if your not in 4WD. By the way , one video in this thread was posted by the revel crew, you can see a 4wd revel with 120 mm cloudwheels. I think it’s a the best AT option for a revel kit.
Hubs were designed to fit standard Kegel, can’t confirm to fit Revel Kit Direct Drive.
A minor modification of the hub is enough to fit any direct drive with Kegel pattern by using a progressively larger size drill bit to enlarge the holes.
Yes, bearing spacer is standard at 10mm wide.
6"x2" tires are available in limited quantities, please PM.