New DPV - Dive Xtras

[stuartv]

Get the bigger batteries.
"I wish I had a lower capacity scooter battery" said no one ever.

Understood.

But, someone might say "I wish I had spent the same money for 4 x 9Ah as what I spent for 2 x 12Ah". I mean, that does give you more total run time... (over 2 or more dives).

$70 for a Waitley 9Ah versus $222 for a DeWalt 12Ah.

Even with the 12s, I would LIKE to have 2 pairs, just 'cause I like to have backups of important things. That's $888 just for batteries! (versus $280 for 4 x Waitley...).

But... I'll probably get some 12s...

 

[rng]

Is a DeWalt 15 or 16 on the horizon and do you expect it to fit in the current BlackTip with no mods?

I saw a picture of an exploded view of a DeWalt 9Ah. It LOOKED like it was just a casing assembled around a bunch of 18650 cells. Meaning, it looked like one could easily disassemble it and replace the 18650s. Are the DeWalt 9 and 12 the same overall size? Is the difference between them simply that the 12Ah pack uses the same number of 18650 batteries, but ones of higher individual capacity?

Is the Waitley 9Ah the same? Could one take it apart and rebuild it with top shelf 18650s to end up with a 12Ah (or more) battery pack?

FWIW the 12ah are 21700 cells as are the newer 9ah packs - the 6, 9 and 12ah flexvolt packs are the same size.

 

[Primary]

A few ounces positive on a smaller scooter sucks big time!

I like to keep the scooter slightly positive. When not in use, I let it float up under my arm and I hardly know it's there.

In use, I never found a little buoyancy to make a scooter (Blacktip or Aquaprop) ill mannered but that's just my opinion.

 

[_Ralph]

I like to keep the scooter slightly positive. When not in use, I let it float up under my arm and I hardly know it's there.

In use, I never found a little buoyancy to make a scooter (Blacktip or Aquaprop) ill mannered but that's just my opinion.

What you talk about above vs. What happens when you do take the steel plate out are 2 different ‘a few ounces’

Unless both of mine have more weight in the steel than everyone else’s...

_R

 

[rjack321]

Is a DeWalt 15 or 16 on the horizon and do you expect it to fit in the current BlackTip with no mods?

I saw a picture of an exploded view of a DeWalt 9Ah. It LOOKED like it was just a casing assembled around a bunch of 18650 cells. Meaning, it looked like one could easily disassemble it and replace the 18650s. Are the DeWalt 9 and 12 the same overall size? Is the difference between them simply that the 12Ah pack uses the same number of 18650 batteries, but ones of higher individual capacity?

Is the Waitley 9Ah the same? Could one take it apart and rebuild it with top shelf 18650s to end up with a 12Ah (or more) battery pack?

Same number of cells just higher quality and capacity in the dewalts. You do get more runtime from 2 sets of waitley's vs 1 set of dewalts but of course you have to change them and keep them dry on the boat between dives. And not have an especially long dive. But even at $500, 2 sets of dewalts is pretty budget. Or one set of dewalts and a second backup set of waitley's.

 

[Primary]

What you talk about above vs. What happens when you do take the steel plate out are 2 different ‘a few ounces’

Unless both of mine have more weight in the steel than everyone else’s...

_R

Without the steel plate and with 2x12AH batteries, my Blacktip is a few ounces positive in saltwater and right where I want it to be. That's all I can say

 

[macado]

Is a DeWalt 15 or 16 on the horizon and do you expect it to fit in the current BlackTip with no mods?

I saw a picture of an exploded view of a DeWalt 9Ah. It LOOKED like it was just a casing assembled around a bunch of 18650 cells. Meaning, it looked like one could easily disassemble it and replace the 18650s. Are the DeWalt 9 and 12 the same overall size? Is the difference between them simply that the 12Ah pack uses the same number of 18650 batteries, but ones of higher individual capacity?

Is the Waitley 9Ah the same? Could one take it apart and rebuild it with top shelf 18650s to end up with a 12Ah (or more) battery pack?

The newer DeWalt packs (FlexVolt 9Ah and 12Ah) are not using 18650 cells anymore. They're using 21700 cells (21mm x 70mm). My understanding is this is the new cell format that was developed together with Tesla and Panasonic. There is also the 20700 (20mm x 70mm) format to make things more confusing. The Tesla cell is slightly longer..well. 1mm longer to pack a bit more density. c

This post shows them using 20700 cells but I *believe* the newer packs are using 21700 now.
Syonyk's Project Blog: DeWalt 20V Max 6.0Ah Pack Teardown & Analysis

This post claims the DeWalt 9Ah packs uses Samsung 30T 21700 and the DeWalt 12Ah pack uses Samsung 40T 21700
New Dewalt 20V Max 8.0Ah Cordless Power Tool Battery

Samsung 30T 21700 3000mAh 35A Battery
Samsung 40T 21700 4000mAh 35A Battery
Both cells are capable of 35A continuous discharge..


But the answer to your question is yes. You could conceivably rebuild the packs with higher density cells to get a larger battery. I assume the Waitley packs might still be using 18650 cells but I don't own a pack to check myself.

EDIT: It is interesting that Samsung also makes a 5000mAh cell now. The Samsung 50E but it's only rated for 9.8A continuous discharge. I'm not an electrical engineer but I wonder if that would be enough for the Blacktip?

The DeWalt packs are using 5S3P (15 21700 cells, 5 cells in a series, 3 series in the set). A pack with Samsung 50E cells should give ~15Ah capacity. Let's hope DeWalt releases one otherwise I suppose you could buy Samsung 50E cells and rebuild the pack if you were so inclined

In theory a 15Ah DeWalt pack using Samsung 50E cells could give a runtime at cruise speed (150ft/minute) of around ~153 minutes. That wouldn't be too shabby for a 24lb scooter.

EDIT2: I missed @rng 's comment above where he basically said the same thing.

 

[Jeremy Williams]

The Waitley 9ah packs are indeed using 18650.

 

[stuartv]

Thanks for the info @macado.

If you buy 30, the 50Es are $6.25 each. So, $187.50? Buy 2 9Ah packs and 30 batteries and you could have 2 15Ah packs?

 

[rjack321]

Thanks for the info @macado.

If you buy 30, the 50Es are $6.25 each. So, $187.50? Buy 2 9Ah packs and 30 batteries and you could have 2 15Ah packs?

you missed the part about them only being rated for 9.8A discharge. They will self destruct in your scooter which pulls more current than that. So that's a big no no
You need a cell with 5000mah capacity AND at least 20A discharge. Not exactly sure how much current the motor draws at max speed but its way over 10A.

you also need a spot welder and some willingness to risk burning down your garage if you really screw it up