The barrel is 1,45cm tall with a diameter of 2,5cm
The cone is 1,4cm tall with a diameter of 2,4cm/1.8cm
I think they were slightly taller from factory, they are visibly warped.
I always overtightened the bushings. I wonder if 2x barrels are better for me, at the same time I like the characteristics of these when they were new and tight. Perhaps higher hardness, or larger size? You are the expert.
on my revel i used first a combo cone and barrel but i ended up with a double barrel 97a riptide.
It does. You will wreck any battery if you ignore the critical voltage warning, slow down, wait for the voltage to recover and keep riding. Drill, chainsaw, skateboard, etc. You can destroy the battery on a single “long range test” ride. Remember that if you damage even a single cell, the enitre battery is compromised. A compromised battery can loose voltage very fast in ways that can be dangerous.
A critical voltage alarm is a warning that riders should not ignore. Automated power downs are an even more important warning. Never restart and continue to ride a board that has powered itself down due to low voltage.
If you find yourself overtightening the cone/barrel combination then switching to two barrels is probably a good idea. I’m in the exact same boat as you. I have 95a cone/barrels. I can’t get them stiff enough for my tastes so now I want double barrel bushings and perhaps 97a or even harder.
For anyone interested, this is what the inside of a 216wh revel kit battery looks like.
I saw discussions back and forth earlier about the type of batteries. This has more or less been confirmed since then, but I have seen no one take the time to disect one. I can confirm that they are Samsung 30Q cells in 10s2p configuration.
The white goo is an insulator used both in the batteries and inside the kit itself. (The little bit of goo on top of one of the batteries is not a leak… Just more of the same insulator)
I do NOT recommend opening your own batteries… Simply because revelboard do not recommend this. But if you do, I’m curious if you have the same/different wear. And perhaps we can learn from each other.
As you can maybe tell, there is dust and some light corrosion starting to form on/around some of the terminals. This is a big no no, and I wish I caught it earlier. This is not something I blame the batteries for. I live in Sweden, I rode in winter conditions. This means salted roads and mud…
Overall this battery still works fine, some lost range from harsh conditions but no sudden shutdowns or issues.
I have cleaned off the outer corrosion to the best of my abilities.
This is my other battery…
It is in worse shape…
Here there is no corrosion on the terminals which is good! (Still dust, but no corrosion) but two other problems. First off the shielding tape is missing on one side. I did NOT take this off. It was never put on from the factory.
More importantly, the soldering to a critical wire has snapped off. It was only held on by a thin layer of tin at the top.
Both battery packs have burned holes through the protective tape. I assume I am not the only one with this problem?
If someone decides to open their batteries I take no responsibility. But if you do, it is important to know that the wires connecting the USB-port are thin and fragile, be careful and lift slowly. Also make sure they are out of the way when screwing back together. Don’t make the same mistakes the guys at the factory did with my broken battery… The screws graced the wires and they are frayed. (Not my fault) but it still works.
The screws are Philips #1. You will need a long thin screwdriver for the deep holes, an even thinner screwdriver for the corner screws.
I am not an expert at all, I am not sure how dangerous this is, so treat it with caution. I used gloves and tweezers when touching wires. I cleaned battery corrosion and the BMS with isopropyl alcohol. I had no issues.
I am reluctant to hijack this thread into a bushing thread so please post your questions here: Bushing and Truck Setup Help Offered and I will answer them there also so everyone can benefit.
So I deleted and re-posted to your thread.
This is correct. Any voltage “recovered” after voltage sag can be used until voltage at rest is at the minimum (2.5v for 30Q). No BMS will allow resting voltage of a cell to go below that and turn back on.
@murdomeek
If you follow that advice you will almost certainly damage your batteries and/or greatly reduce your range. Following the advice of BP, you would also be doing the exact opposite as is recommended by respected esk8 manufacturers including Boostedboards and Onewheel. They both say to promptly come to a safe stop as soon as possible after a low battery warning (Beep or kickup). The Revel kit manual does not include these instructions but it should.
BP is a troll who visits different threads pretending to know stuff. He recently accused the owner of metroboards of not knowing how to tighten axle nuts. BP is often wrong and typically turns to insulting people when he is found out. I’m sure the pattern of insults will be confirmed in his next post to this thread. He is currently trolling me and others in other threads.
I’m giving you the benefit of my experience using lithium battries. Most of my lithium batteries are in peak condition up to five years after purchase. This includes Boosted boards, my original Onewheel and all but one of my Ego power tool batteries.
The only damaged batteries are the ones that I over depeleted by ignoring battery warnings, waiting for the voltage to recover and then running on recovered voltage. This was before I knew any better.
I don’t want to repeat all the information in my previous post but i have real experience with batteries malfunctioning the next day after running past battery alerts. These experienced include an Ego chainsaw battery and a long range test that I did with my first two L3-x batteries. Since revising the way that I use lithium batteries, I have had no other failures. I have eight L3-x battereis that are in perfet condition. Also have 10 ego batteries that are in perfect conditon. These are each three to five years old.
Batteries are expensive. They can last for five to ten years if you use them right. But they usually only have a six month warranty. So stay well above critical voltage and you will have more fun and spend less.
Here is an excerpts from the EGO battery manual. Notice that they suggest immediate charging after a low battery warning. The flashing red light usually happens long before the power cut-off.
If you ignore the warnings, you risk damaging your battery.
Nice, vague user manual. What is the cutoff of that BMS? What cells are they and what is their voltage sag at what amp draw? Wtf is “recovered voltage”? Cells don’t recover voltage, they sag under load then go back to a resting voltage when not under load. Have you ever looked at a discharge curve of any battery? A cell reaches cutoff sooner at a higher amp draw. Lower the amps and you can keep using it for a bit more. Evolves drop to to eco mode on low battery for this very reason. Just because the battery voltage is too low to sustain high power output does not mean it’s dead, just means you need to lower the power draw.
But nah course I’m just trolling, you seem like you know it all, go ask some other battery builder what they think of your analysis then. Apparently you are expert on everything, jump to conclusion right away “definitely wrong material, definitely don’t do this because my chainsaw user manual says this”. I’m gonna call and get a refund on my mech-e degree because apparently I don’t know shit. Thanks.
So if we use it as advertised then damaged batteries should be covered under some warranty by revel boards. Otherwise they need to update their documentation.
This would’ve swayed my purchase if this recommended use was advertised.
If you like to ride long distances then the best way to do that with a Revel Kit is to have spare batteries. In my opinion, the worst way is to have only one battery and ignore multiple low battery alerts until you come to a hard stop. This is not a criticism of the revel kit. Regardless of what brand you ride, critical battery alarms are there to protect your battery and should not be ignored.
Edit:
I deleted most of this post because it is redundant with this one:
Did you mean one bar consumed or one bar remaining. I assumed you meant one bar remaining.
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.
