DPV lithium conversion

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Actually I have an Xjoy 2 which is discontinued. I will contact Suex, though, that is a good idea.

Thanks
 
tbone-
In the US, they have a distributor or subsidiary called "Tracer Power" at
TracerPower.com Tracer LiFePO4 Battery Modules
who answer the phone and email without the problem of translating from Colonial English to UK English.
One of the power units on that page is something like 160AH at 12V, so it may be worth giving them a call. Some of the units are indeed stocked here in the US.

Charging anything in series or parallel can be an issue, since the reality of how chargers and batteries will spread power, or perhaps deceive each other about power, still don't seem settled. As best I can tell, if you really want precise charging, it still comes down to a charger matched to a battery, and with lithium of any type, a lot of the companies still call for charge control or monitoring of some sort at the cell level to prevent the unlikely, but predictable, excitement when one cell goes out of bounds.
 
the problem of translating from Colonial English to UK English.
.

couple thoughts, you mean American English versus English.

second thought, if somebody that speaks American English has problems with "translating" English, they should not be doing anything so tasking as writing emails.
 
Charging anything in series or parallel can be an issue,

Not really. Li_ion behaves much like SLA's. Parallel charging is easy if you have the right pack architecture.

since the reality of how chargers and batteries will spread power, or perhaps deceive each other about power, still don't seem settled.

It's pretty well understood. The problem remains the cost of implementation. Most issues result for cell drift, and that requires time. If the time required is longer than the warranty period, or long enough to sell a batch and dissolve the company then why bother with a costly solution?


As best I can tell, if you really want precise charging, it still comes down to a charger matched to a battery, and with lithium of any type, a lot of the companies still call for charge control or monitoring of some sort at the cell level to prevent the unlikely, but predictable, excitement when one cell goes out of bounds.

Cell level monitoring and cell balancing during charging is:

Complex

Expensive

Often Ineffective

Often implemented poorly

And assumes the cells were allowed to be out of balance in the first place.

Proper pack design can greatly reduce these problems passively, but that's also not cheap or easy.

Tobin
 
@Rred unless they do custom packs, they aren't going to be usable as a supplier. these dpv's are largely 24v, and no way the 170ah pack they have will fit in any of these tubes. Companies like Ping and Battery space will custom configure a pack that fits the dimensions you want, with the right BMS, and the appropriate charger. Not sure why you are pushing Tracer since they are very much not appropriate for what we're trying to accomplish.
The link that you provided says the following

"Unfortunately, due to shipping regulations it is not viable for us to ship lithium batteries by regular courier to the USA, Australia or South Africa. If you have a large requirement, or wish to distribute our products, please contact us for a freight quotation."

nowhere is there anything that indicates they can ship their batteries within the US to normal people
 
I recently acquired an older 42AH Gavin scooter. I know the batteries are a little older and was warned they have limited battery life left. I was considering a lithium conversion. Anyone done this conversion before?

Oceanic based scooters have ~400-500 watt motors. That's a given. When SLA's walked the earth with ~10 watthours / lbs (meaning an hours worth of battery needed drive 500 watts would weight 500/10 = ~50 lbs then massive scooters were necessary.

Lithium will yield ~80+ wathours / lbs. 50 lbs of Lithium will run that same motor for ~8 hours. That does makes little sense.

Lithium upgrades are worth considering if you can either increase the power output, (Dive X Fury maxes at about 1200 watts) or reduce the displacement (smaller lighter hull) or both.

Lithium upgrades for a scoot originally designed for Nimh (~20-25 watthours / lbs) makes some sense, the increase in runtime is useful, ~3-4X.

Lithium upgrades for power limited SLA scooters make much less sense if you can't reduce the displacment.

Good luck,

Tobin
 
Cool-
"Often Ineffective...Often implemented poorly"
That's about all the makers seem to agree on. In laptop packs, they are often a 3x3 series/parallel array with sensing and charging monitored at each cell in the array. In larger packs like a Tesla, not so much. And yet somehow, even in simple batteries like the Boeing's use, they find a way to get out of balance and catch fire. I'm familiar with the specific and conflicting recommendations from several vendors, and at least one generally well-recommended vendor that got out of the BMS end of things because they finally gave up trying to discover the "best" way to do things.
With SLA, if you screw up,ok, you kill the battery. With lithium, the screw-up becomes much more expensive and with the exception of LiFePO4, often quite exciting. As long as the user knows what they can expect, no problem. A number of researchers are all saying one same thing though: There are a number of other potential chemistries that just don't have the same dendrite problems that lithium does. Lots of people working on that. Which of course does no good if you need something now.(G)
 
guyharrisonphoto,

let me know what you find out. I have an XJOY 2 also, and would like a lithium battery. The guy I bought the scooter from tried to do this conversion too, but ran into issues with the motor not responding well to the pack.
 
Oceanic based scooters have ~400-500 watt motors. That's a given. When SLA's walked the earth with ~10 watthours / lbs (meaning an hours worth of battery needed drive 500 watts would weight 500/10 = ~50 lbs then massive scooters were necessary.

Lithium will yield ~80+ wathours / lbs. 50 lbs of Lithium will run that same motor for ~8 hours. That does makes little sense.

Lithium upgrades are worth considering if you can either increase the power output, (Dive X Fury maxes at about 1200 watts) or reduce the displacement (smaller lighter hull) or both.

Lithium upgrades for a scoot originally designed for Nimh (~20-25 watthours / lbs) makes some sense, the increase in runtime is useful, ~3-4X.

Lithium upgrades for power limited SLA scooters make much less sense if you can't reduce the displacment.

Good luck,

Tobin

Thanks for the feedback. Decided that the lithium may not be worth the upgrade at this time. Think I'm going to stick with SLA. Looking at new batteries.

Is there a reason Genesis batteries are so much more expensive? Seems like i can use Duracell or vmax batteries for half the cost with a higher advertised AH rating. Genesis are a few lbs heavier but only 42AH compared to 46-50 for the Duracell and vmax. All the same physical size.

What gives?
 
AH ratings aren't always given at the same current draw. If the draw is really low, the battery can give a lot more AH so most people quote at c/20 draw or something like that. I.e. the powersonic 20ah battery vs. the Genesis 16ah batteries. The Powersonic seems like it would be 25% more in the same package, but when you put it under a 1C draw similar to a dpv, it only gets about 14-15ah when the Genesis gets the full 16ah.
 
http://cavediveflorida.com/Rum_House.htm

Back
Top Bottom