GRAPHENE BATTERIES ?

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Not going to happen. Pumping that kind of energy that fast though the existing cables and EO ports would melt everything.

I didn't say a G3.1. I said a G3.1-sized scooter....

Also, even with an actual G3.1, a BIG chunk of the charging time is after it slows way down to do the last 10 - 20% of the capacity.

With graphene-based batteries, maybe it would be possible to continue charging at the full 275W all the way until full. I think that would cut at least 2 hours off the charging time on a 1700 W-Hr scooter.

And if the existing wiring could take any amount more charging current, then even better. Cutting the charging time on a G3.1 down to 2 hours or so would be pretty spectacular. Getting a 90+% charge between dives would become very feasible - if you're diving somewhere with power, of course.
 
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 they claim in the article would be groundbreaking. 45% increase in capacity and double or even 5x faster charging. Actual new tech trickles down into the hobby industry and some point but anything that actually has better efficiency, capacity or whatever is picked up by big money industries first.
It doesn't even make much sense for power tools. Every dude that uses cordless tools all day has at least 1 or 2 batteries charging while working. If you had better capacity and faster charging you still would have at least 1 or 2 batteries charging while you work. For scooters it's even less usefull. Something like a suex xk1 has a range of 4 or 5 (?) miles... who does more than one of those dives in a day. Having same day charging vs over night charging for DPVs doesn't even give you any real life benefit, IMHO. At least I don't see it.

If it trickles down into the hobby industry, the dive industry is the trash bin in back that gets the broken leftovers, lol. Everything is 10 years behind current tech.

 
But, I suspect that a scooter with a range of 5 miles means you can really only penetrate 1.7 miles or so.
1.7 miles is pretty far and you would tow a backup scooter per team. I don't really see inbetween-dive charging as an upside... but I only ever do one longer (cave) dive per day rather than 2 shorter dives, so there is that.

... or want to do more than one dive per day to more than, say, 1 mile. 5000 feet (i.e. 1 mile) in a cave is not THAT far. I am only a baby cave diver and I have swam (no DPV) 8000 feet (total) in one dive.
A ccr lets people swim very far into a cave with little experience... make sure you don't cut corners and kill yourself. 1 mile into a cave is very far when your ccr craps out and you're all of a sudden doing you're first ever OC cave dive back home. It might not feel far when everything goes to plan.
Something like the XK1 IMHO is overkill for 80% or 90% of people who buy them.
 
If it trickles down into the hobby industry, the dive industry is the trash bin in back that gets the broken leftovers, lol. Everything is 10 years behind current tech.
I'm not sure what you mean. Did you read the article and are you saying that these batteries for RC toys have 45% more capacity and 5x charging compared to what in a new Tesla for instance?
 
I'm not sure what you mean. Did you read the article and are you saying that these batteries for RC toys have 45% more capacity and 5x charging compared to what in a new Tesla for instance?
The tesla cells are unimpressive at best. There's nothing special about them.

Different usage cases and goals. A tesla batt that cost 5x the price while offering 45% more performance wouldnt sell. An RC batt that does would fly off the shelves.

RC prismatic cells already have packs rated for 30c charge rates and 100c+ discharge rates. Nothing in a 18650/21700/etc form factor comes close.

Capacity has hit a wall in the past ~5-10 years. There hasnt been much improvement from anyone in that area recently. Small evolutions, but nothing ground breaking.
 
Capacity has hit a wall in the past ~5-10 years. There hasnt been much improvement from anyone in that area recently. Small evolutions, but nothing ground breaking.
Yes, I agree, but that's not what they claim in the article. I don't think I understand what you're getting at.

My only point is that I think what they claim in the article is BS.
 
Funny you should use that example. I was talking to a cave diver just in the last couple of days who has been using a Suex and wants more capacity because he was able to do one dive and came out with 39% battery. He wanted to do a second similar dive in the same day, but could not without charging his scooter up in between dives.

Charging a scooter in between cave dives can be problematic - unless you have a generator and bring it with you...

I am not trained in Cave DPV use (yet). But, I suspect that a scooter with a range of 5 miles means you can really only penetrate 1.7 miles or so. 1/3 in, 1/3 out, 1/3 in reserve. I suspect there are plenty of cave DPVers who either want to penetrate further than that on one dive, or want to do more than one dive per day to more than, say, 1 mile. 5000 feet (i.e. 1 mile) in a cave is not THAT far. I am only a baby cave diver and I have swam (no DPV) 8000 feet (total) in one dive. Swimming that took 4 hours. But, with a scooter, a 1 mile penetration and back out is (I'm guessing) a dive that is well less than 2 hours. So, definitely something a person might want to do more than once per day.

Also, several experienced scooterers have remarked to me how nice (convenient) it is to have a scooter with enough capacity that they can use it for a whole weekend (or more) without having to charge it.

Some people like to dive and also camp at or near their dive site. They probably wouldn't have the ability to charge a scooter at all.

Ultiimately, yes, we do have scooters now that (arguably) don't really need more range. The Genesis 3.2 (17 mile range) and Seacraft Ghost (20 miles) are examples. But, those scooters are heavy. The G3.2 is 50#. My personal experience is that a 50# scooter can be a real pain in the butt in a lot of situations.

A scooter with the same range as a G3.2 that was 15 - 20 # lighter (by virtue of having half the batteries with double the capacity) as well as 10+ inches (25+ cm) shorter would be a huge benefit. Being able to charge 5X faster would also be a big benefit - to SOME few folks.

Be glad you're coming into this at a time when you think 50lbs is a heavy scooter, 10years ago it was a true luxury to have a scooter that was that light but the other issue with them getting lighter is that they are all twitchy. Too much power, not enough stability for cruising for 9000ft. A UV26 is far more comfortable than a Genesis for long hauls like that because it weighs twice as much. Torque reducing fins are relatively new in the space in the last 5 years, but even with those the lack of mass makes them twitchy when going for long cruises.
Things like the Anker Solix F2000, Ecoflow Delta Pro, etc. are all perfectly reasonable ways to recharge a dpv from a car, and people are far more likely to pay $2k for something like that which can recharge those dpv's about twice from a normal dive vs. paying an extra $2k for a bigger battery just so they don't have to charge. People ask for it, they want it, but they don't put their money where their mouth is when it comes time to actually purchase them.

Anyone actually going 9000ft into a cave has a backup dpv with them for safety. May only be one for the team, but you definitely have at least one spare, and I don't know anyone who would do a pair of 9k ft penetrations in a day. 9k total is fine, I do that fairly regularly if I want some trigger time in Ginnie or JB, but one the way out with the flow you aren't using a third in and a third out anyway.

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.

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
 
Yes, I agree, but that's not what they claim in the article. I don't thing I understand what you're getting at.

My only point is that I think what they claim in the article is BS.
It is BS. Everything the article quotes is from 2016/2017. If it was really as revolutionarry as they try to make it, it would be in a lot more things by now.
Graphene has been the new hot thing for 5+ years now with no groundbreaking improvements.

IMO the next big leap will be in safety, different construction/electrolyte so they dont catch on fire as easily. LiMn/LiFe were on the right track, but couldn't match capacity of traditional chemistries.
 
1.7 miles is a pretty far and you would tow a backup scooter per team. I don't really see inbetween-dive charging as an upside... but I only ever do one longer (cave) dive per day rather than 2 shorter dives, so there is that.


A ccr lets people swim very far into a cave with little experience... make sure you don't cut corners and kill yourself. 1 mile into a cave is very far when your ccr craps out and you're all of a sudden doing you're first ever OC cave dive back home. It might not feel far when everything goes to plan.
Something like the XK1 IMHO is overkill for 80% or 90% of people who buy them.

As I noted, some people enjoy doing more than one dive in a day. Some caves may not even offer more penetration than 1 mile. And if they scooter in for only 1 mile on the first dive, then they burn 2 miles in total. On a scooter with "4 - 5 miles" of range, that doesn't really leave enough to safely do another of the same dive without recharging.

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. Even having the same range in a smaller, lighter package is beneficial to some.

Regarding myself, I didn't go 4000' from the entrance and then turn around. I went in, then back, then down another line, and so forth. I was never more than something like 2000' from the exit. 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. To be honest, I would say I am more skilled and more comfortable on OC than I am on CCR (though I am quite comfortable on CCR).
 
https://www.shearwater.com/products/teric/

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