GRAPHENE BATTERIES ?

[stuartv]

Current gen lithium batts can already be charged at 1c or more depending on the quality.
BMS capabilities and charger size is the main limitation.
Anything over a ~1000w charger is going to require 220v and/or a custom plug. Most people dont want to deal with that hassle.

What is "charged at 1c"? Is that the same as charging at 1 amp?

My Genesis charger is 275W (IIRC). It takes something like 6 hours to charge my 2.2 from a 20% charge to full. Something like 2 or 3 hours of that is just charging the last 10% or so, where it is charging at MUCH less than 275W.

If the charger could run at 400 - 600W and hold that level all the way until full, that would cut total charge time tremendously. No need for a 1000W charger.

 

[berndo]

Just because YOU wouldn't get any "real benefit" does not mean that more range and faster recharging are not beneficial to the scuba community at large.

I just don't think it's very realistic. All the people I know who do long, multi mile dives in caves do one dive a day. Those dive also tend to require a bunch of deco unless you're in Mx.
I'm not sure how many people actually need or would wanna pay for more range. As I said, IMHO something like a XK1 is overkill for most people that buy them.

And those batteries aren't a thing.

 

[berndo]

Also, I did full cave and stage cave on OC before I did CCR Cave. An OC exit would not be an issue for me.

Doing the classes is one thing, having experience is another. Just saying because you called yourself a 'baby' cave diver.

 

[stuartv]

Be glad you're coming into this at a time when you think 50lbs is a heavy scooter

I am! LOL!

Either way, the quantity of people actually doing those dives who would be interested in a dpv like that are extremely few and there is not enough of a ROI for the manufacturers to bother investing in that technology to sell a dozen of those units a year, just not enough money to bother with. If the cells come out and you can drop them into something like a Warpcore then great, but I think it will be another 5 years before anything truly major happens in the DPV world, too much volatility right now.

But that is part of the point. The Genesis Warp Core is already here. If somebody produces graphene 18650 cells that have more capacity and can charge faster, then they should just drop right into a Genesis. The only thing the manufacturer might need to do is possibly make an updated charger, if they want customers to be able to take advantage of the faster charging. And/or possibly updated BMS firmware?

The additional capacity/range would be available to the user without any redesign from the manufacturer.

Also regarding charge rates, remember this. Standard wall outlet, 15a@120v=1800w, 90% efficiency on the charger=1600w coming out of it, probably 95% efficiency of actually charging the batteries means 1500w going in, but still needs absorption so a 2kwh battery still needs a full hour to charge just limited by the wall outlet. Practically though most try to limit input wattage from a standard wall outlet to about 1200w absolute max because it's rare that it is the only device on that circuit so you don't want to max it out, so that comes out roughly to 1000w going into the pack at a max but that's where the balance comes into play. You have a dpv, your buddy has a dpv, if you're doing a pair of big dives you probably used the backup dpv to keep it cycling, so now you have 3 dpv's trying to charge so do you put one of them on and charge for 2 hours then have to cycle them out or do you put them all on a 200w charger so you can charge all three of them and your canister lights all on the same circuit? That's most of why the chargers are so small.
Pumping that much power into a pack is also going to generate a lot of heat, EV batteries are actively cooled, DPV's are not so the charge rates are going to be limited by how much of that heat can escape. Just talking about the practicality of charging these things wicked quick, 1-2hr charge rate is certainly quite fast and attainable to deal with on a SIT

The Genesis charger pumps 275W. I can only speculate that the main reason for going so slow is to keep the heat down. I also speculate that if graphene batteries can take a charge SO much more quickly, then they could probably take double the rate the Genesis charger currently operates at without getting any hotter than the current cells do at 275W. Of course, that is total speculation and could be totally wrong.

The current Genesis charger will get a 2.2 up to around 90% charge in a relatively short amount of time. At least, compared to how long it takes to get to 100%. If graphene allowed one to charge to 90% in an hour or less, that could be pretty handy in a lot of situations.

My truck has a 400W outlet (when the engine is running). If a Genesis could get to 90% of charge in less than an hour, running a 400W charger, it would be very feasible for me to charge my scooter just from running my truck engine between dives.

Anyway... all of this is just to say that I think it's great that graphene battery tech has been around for a while and is advancing. Fingers crossed for 18650 cells soon that offer a big bump in capacity, with much faster charging (at the same heat level or less), and more discharge current capability (at the same heat level or less). If nothing else, just having the longer range would be nice.

If the Genesis motor could handle more current, having more thrust available could fix my only bragging rights problem that I currently have, because of my one buddy with a CudaX.... LOL! It's only for 1 minute at a time, but he can still claim 108# of thrust, to my max of 90#. And that is probably enough to give him all the head start he needs to whup me any time we drag race.

 

[stuartv]

I just don't think it's very realistic. All the people I know who do long, multi mile dives in caves do one dive a day. Those dive also tend to require a bunch of deco unless you're in Mx.
I'm not sure how many people actually need or would wanna pay for more range. As I said, IMHO something like a XK1 is overkill for most people that buy them.

And those batteries aren't a thing.

You said the Suex has 4 - 5 miles of range.

The Genesis 2.2 and 3.2 are 17 miles of range. The Genesis 2.1 and 3.1 are almost 9 miles. The Seacraft Ghost is 20 miles. The Seacraft Future is 10 miles. The CudaX Explorer is 11 miles. A SS Magnus is 8 or 9 miles.

I know numerous people who have one or the other of those. Maybe they are overkill. Or maybe all those people have valid reasons they have chosen to spend the money it takes to have scooters with that kind of range...

Doing the classes is one thing, having experience is another. Just saying because you called yourself a 'baby' cave diver.

Fair. No argument here.

 

[Whitrzac]

What is "charged at 1c"? Is that the same as charging at 1 amp?

My Genesis charger is 275W (IIRC). It takes something like 6 hours to charge my 2.2 from a 20% charge to full. Something like 2 or 3 hours of that is just charging the last 10% or so, where it is charging at MUCH less than 275W.

If the charger could run at 400 - 600W and hold that level all the way until full, that would cut total charge time tremendously. No need for a 1000W charger.

1c = ah rating of the pack

1c charge on a 35ah pack = 35a charge rate
2c charge on a 35ah pack = 70a
etc

 

[Whitrzac]

The reason for slow chargers is cost, a 150w charger is like $20, 300w around $50, 500w is around $100, Larger ones are uncommon and go up exponentially.

Somewhere around 1c charge rate theres a tradeoff beteween speed and longevity.

 

[berndo]

Or maybe all those people have valid reasons they have chosen to spend the money it takes to have scooters with that kind of range...

I reckon the people that buy 17 or 20 mile range scooters do it because they think it's cool and have money to blow.
Wanting cool stuff can be a valid reason... like buying a Porsche or a Lambo.

 

[BoundForElsewhere]

Elon Musk will perfect the technology, give it a really goofy name, and then make it impossible to purchase unless you join his cult.

 

[tbone1004]

I am! LOL!



But that is part of the point. The Genesis Warp Core is already here. If somebody produces graphene 18650 cells that have more capacity and can charge faster, then they should just drop right into a Genesis. The only thing the manufacturer might need to do is possibly make an updated charger, if they want customers to be able to take advantage of the faster charging. And/or possibly updated BMS firmware?

The additional capacity/range would be available to the user without any redesign from the manufacturer.



The Genesis charger pumps 275W. I can only speculate that the main reason for going so slow is to keep the heat down. I also speculate that if graphene batteries can take a charge SO much more quickly, then they could probably take double the rate the Genesis charger currently operates at without getting any hotter than the current cells do at 275W. Of course, that is total speculation and could be totally wrong.

The current Genesis charger will get a 2.2 up to around 90% charge in a relatively short amount of time. At least, compared to how long it takes to get to 100%. If graphene allowed one to charge to 90% in an hour or less, that could be pretty handy in a lot of situations.

My truck has a 400W outlet (when the engine is running). If a Genesis could get to 90% of charge in less than an hour, running a 400W charger, it would be very feasible for me to charge my scooter just from running my truck engine between dives.

Anyway... all of this is just to say that I think it's great that graphene battery tech has been around for a while and is advancing. Fingers crossed for 18650 cells soon that offer a big bump in capacity, with much faster charging (at the same heat level or less), and more discharge current capability (at the same heat level or less). If nothing else, just having the longer range would be nice.

If the Genesis motor could handle more current, having more thrust available could fix my only bragging rights problem that I currently have, because of my one buddy with a CudaX.... LOL! It's only for 1 minute at a time, but he can still claim 108# of thrust, to my max of 90#. And that is probably enough to give him all the head start he needs to whup me any time we drag race.

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