GRAPHENE BATTERIES ?

[stuartv]

275w is a reasonable balance of charge time, wear on the cells, and cost. It can charge faster, but see the number of things that need to be charged simultaneously. If it's going to take more than an hour, then you may as well let it take 8 hours while you sleep and be able to charge everything.

Your Genesis can handle a much larger charger, 18650's that you bought can easily charge at 0.5c or a bit higher without any concerns at all, but you couldn't run it on your 400w truck inverter which would basically be maxed out with the existing 275w charger. If you had a Ford Powerboost with a real inverter in it then you could charge faster, but even then you are trying to charge a big battery at fast speeds in an enclosed space with no way to shed that heat so regardless of how fast the batteries can charge, how fast can they safely charge inside a confined space with no active cooling..... You'll find when you start using this thing that yours will quite comfortably do two quite large dives in a day without issue at all and the practicality of a dpv that charges that quickly is pretty small. The better use of fast charging batteries will be in the handheld dive light world when they can be charged with USB-C at 165w or whatever and charge in less than an hour between dives, that's where the benefit would really be, not in DPV's

I have already ordered a 2.1 tube for mine, so I can make it shorter and lighter.

I agree that fast charging is not a huge deal for my scooter. But, if the same batteries that can charge quickly can also provide 50% or 100% more capacity, then that would be a big deal.

More to the point: If there were 18650 cells that had double the capacity and 5 times the charging speed, then a Genesis scooter that is more the size of a Seacraft Go!, but with the same range and thrust as a 3.1 becomes feasible. And you could (possibly) do a big dive with it and then charge it back up to 90% during a surface interval before another big dive.

As for my truck's 400W outlet, it's inside the driver's side RamBox. I don't know where the actual inverter is, how it's cooled, etc.. If it can't sustain an actual 400W load, well, that is somewhat disappointing.

Anyway... you guys don't see any value in scooter batteries that are higher capacity and faster charging. That's fine. I will look forward to a smaller, lighter scooter, with just as much thrust and range as I have now, all by myself. 25#, 10 mile range, and 90# of thrust sounds pretty awesome, to me. I'll have to experience the "twitchy" before I decide I don't like it.

 

[BoundForElsewhere]

why don't y'all just get an underwater Kato?

 

[tbone1004]

I have already ordered a 2.1 tube for mine, so I can make it shorter and lighter.

I agree that fast charging is not a huge deal for my scooter. But, if the same batteries that can charge quickly can also provide 50% or 100% more capacity, then that would be a big deal.

More to the point: If there were 18650 cells that had double the capacity and 5 times the charging speed, then a Genesis scooter that is more the size of a Seacraft Go!, but with the same range and thrust as a 3.1 becomes feasible. And you could (possibly) do a big dive with it and then charge it back up to 90% during a surface interval before another big dive.

As for my truck's 400W outlet, it's inside the driver's side RamBox. I don't know where the actual inverter is, how it's cooled, etc.. If it can't sustain an actual 400W load, well, that is somewhat disappointing.

Anyway... you guys don't see any value in scooter batteries that are higher capacity and faster charging. That's fine. I will look forward to a smaller, lighter scooter, with just as much thrust and range as I have now, all by myself. 25#, 10 mile range, and 90# of thrust sounds pretty awesome, to me. I'll have to experience the "twitchy" before I decide I don't like it.

The issue with fast charging is practicality. To charge your 2.2 as it currently is at the speeds the graphene batteries are talking, you are looking at an EV charger on a 50a/240v outlet and the chargers to do it cost around $1500. Sure they exist, but it is entirely impractical *yes the Ford Lightning can actually do it from its inverter, but to my knowledge it's the only vehicle out there with a ~10kw inverter built in*.
Your rambox can sustain a 400w load, the inverter is probably right behind the plug, it's cooled by an electric fan. It can charge your scooter with its current 275w charger which probably pulls 330w or so.

A 25lb scooter with 90lb of thrust actually sounds quite horrific to me. The 50lb units with that much thrust are a handful when you're operating at full thrust, a unit with half the mass would be quite unstable in the water.

 

[stuartv]

The issue with fast charging is practicality. To charge your 2.2 as it currently is at the speeds the graphene batteries are talking, you are looking at an EV charger on a 50a/240v outlet and the chargers to do it cost around $1500. Sure they exist, but it is entirely impractical *yes the Ford Lightning can actually do it from its inverter, but to my knowledge it's the only vehicle out there with a ~10kw inverter built in*.
Your rambox can sustain a 400w load, the inverter is probably right behind the plug, it's cooled by an electric fan. It can charge your scooter with its current 275w charger which probably pulls 330w or so.

A 25lb scooter with 90lb of thrust actually sounds quite horrific to me. The 50lb units with that much thrust are a handful when you're operating at full thrust, a unit with half the mass would be quite unstable in the water.

I think you are missing part of my point.

I'm not saying they have to charge as fast as possible.

I'm just saying to possibly charge them as fast as a standard 15 or 20A household circuit would allow.

AND, if they are capable of charging hugely faster, then maybe that means they could be charged all the way to 100% without slowing the last 10% of charging down to the same crawl my 275W charger does now.

The goal being an overall net effect of maybe charging an 850 W-Hr scooter in an hour or two. At least, to 90% in less than an hour.

You're focusing on "fastest", which is impractical, and ignoring "faster". If "faster" is practical to cut charging time to 1/4 to 1/3 (while still preserving long-term cell health), that would be pretty handy - to SOME people.

Or maybe offer a dual-mode charger. A "slow" mode that is good for cell health, when you have time for it. And a "fast" mode that you can use during a surface interval, when needed. Or maybe it just always runs "fast" up to 90%, then slows down, and no need for two modes.

As for 90# of thrust in a baby scooter... well, I haven't gotten to play with my Genesis enough yet. I've never driven anything (beefier than a BlackTip) that was actually running at max thrust for any length of time. However, the same statement comes to mind that I also have when people talking about some motorcycles and saying that they have "too much" power. "Just because it's there doesn't mean you have to use it." As long as the throttle is not a light-switch and I can control the speed with precision, I'd be happy to have 150# of thrust available.

If it's super light and super powerful, maybe it just needs to be longer and skinnier, instead of really short and 8" across. And maybe with some small stabilizing fins/vanes at the front. If BMW can make an S1000RR that is short, light, 200 horsepower, and still stable to ride for fun on the street, I think the scooter manufacturers can find a way...

 

[Whitrzac]

"AND, if they are capable of charging hugely faster, then maybe that means they could be charged all the way to 100% without slowing the last 10% of charging down to the same crawl my 275W charger does now."

Nope, still need the cv stage to balance the cells.

 

[stuartv]

"AND, if they are capable of charging hugely faster, then maybe that means they could be charged all the way to 100% without slowing the last 10% of charging down to the same crawl my 275W charger does now."

Nope, still need the cv stage to balance the cells.

I will stipulate to that and just say this: If they are only 11% higher capacity than the current 18650 cells, then I can charge them very quickly to 90% and still have as much range as I have now, and that would be just as good. If they are more than 11% higher capacity, then that is just bonus range.


I don't pretend to understand BMS very well and the balancing it does. Very unclear on why it has to slow the charging down to milliamps for the last 10% or so, and why it would have to slow it down to just as slow for graphene-tech cells.

 

[Superlyte27]

The issue with fast charging is practicality. To charge your 2.2 as it currently is at the speeds the graphene batteries are talking, you are looking at an EV charger on a 50a/240v outlet and the chargers to do it cost around $1500. Sure they exist, but it is entirely impractical *yes the Ford Lightning can actually do it from its inverter, but to my knowledge it's the only vehicle out there with a ~10kw inverter built in*.
Your rambox can sustain a 400w load, the inverter is probably right behind the plug, it's cooled by an electric fan. It can charge your scooter with its current 275w charger which probably pulls 330w or so.

A 25lb scooter with 90lb of thrust actually sounds quite horrific to me. The 50lb units with that much thrust are a handful when you're operating at full thrust, a unit with half the mass would be quite unstable in the water.

You should dove it. My 25lb Genesis scooter with 90 lbs of thrust can almost be flown hands free. At 60% power, it can be flown hands free. The anti-torque veins work spectacularly.

I have no issue doing 12k’ dives on full power with a Genesis 2.1 or 3.1

 

[Whitrzac]

I will stipulate to that and just say this: If they are only 11% higher capacity than the current 18650 cells, then I can charge them very quickly to 90% and still have as much range as I have now, and that would be just as good. If they are more than 11% higher capacity, then that is just bonus range.


I don't pretend to understand BMS very well and the balancing it does. Very unclear on why it has to slow the charging down to milliamps for the last 10% or so, and why it would have to slow it down to just as slow for graphene-tech cells.

This was just the first clickbait thing that popped up when I googled for an explanation better than what I could give.
Most lithiums cant be charged past 4.2v a cell, so once it gets to that voltage the charger switches from cc(constant currant) to cv(constant voltage) to top off the battery.

Lithium Charging Stages​

• Stage 1 is your constant current stage and accounts for roughly 80% of the battery's state of charge. This stage of charging is maintained by sending a constant, relatively high current to the battery.
• Stage 2 is a constant voltage stage. Once the battery reaches its voltage limit of 14.7V the charger holds the voltage constant and reduces the current gradually down to 0 until the battery reaches a full charge. At this point, the battery is charged to 100%.
  

 

[berndo]

But, if the same batteries that can charge quickly can also provide 50% or 100% more capacity, then that would be a big deal.

It really would be a big deal for scooters though, tbone explained why. It's also not going to happen any time soon. You're arguing over a fantasy tech that doesn't exist.
We already have small and light scooters that run for much longer than what +90% of divers need or will ever need. Having faster charging wouldn't change anyones dives at this point either. You seem to think more would be better but in real life, it really wouldn't make a difference.

 

[grantmac]

The real next step in batteries is solid state (not liquid electrolyte), these are already in production. The issue is that EVs are going away from the 18650 so it's likely you'll need an entirely new battery arrangement to take advantage.
The step after solid state is changing from lithium to something a lot more common such as sodium. This is at the technology demonstrator state at the moment. Again unlikely to be in the 18650 form factor.