Question Heated Vest - Santi Flex 2.0 vs. Light Monkey DTEK

[JohnN]

The problem as @Superlyte27 mentioned is thermal runaway
It is irrelevant if the battery pack is watertight. A lithium battery's worst enemy is heat.
The most probable cause of a lithium battery over heating is a short circuit in the electronics and/or wiring.
There are many ways and points that can cause a short to happen, starting from a defect at assembly of the battery pack to the wiring from the battery to the vest, a defective battery prematurely going dead in the pack, and the bms.

Once the battery goes into thermal runaway there is absolutely nothing you can do to stop it other than (pun not intended)runaway, and the heat from that one battery burning will cause all the other batteries in the pack to also go into thermal runaway.

Anything electric or combustible inside a dry suit that you don't have the option of shutting it down reliably from the outside is a big risk.
Doing a techdive or a cave dive, you have enough risk to deal with already, adding a potential fire hazard in the mix is not wise, especially if there is other options to make it all safe.
A recreational dive in a dry suit can also become catastrophic with a battery in thermal runway. you still have to get back to shore or on the boat which could take long enough that you will be in a spiral of trouble.

An exterior battery that you can disconnect like a breaker in you electrical panel at home just make a whole world of sense. If your electronics only gets stuck in the on position and you cant stop it consider your self lucky compared to potential bigger hazard of having a ticking timebomb in your pants.

you can easily go on YouTube and see lithium batteries in thermal runaway in action, it will be a eye opener.

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Again, battery technology and protection has advanced quite a bit. Please show me a reference to where either a Thermalution or Venture Heat battery went into thermal runaway.

 

[dogbone]

Again, battery technology and protection has advanced quite a bit. Please show me a reference to where either a Thermalution or Venture Heat battery went into thermal runaway.

I'm a sport that's all about mitigating risk, it feels like an unnecessary risk to take, because technology may have advanced... Be like taking a bungee cord that has previously snapped Bungie jumping saying, repair tech has come a long way... It may save a little bit of money to go that route, but it doesn't mean it's better... Especially in a sport where an unmanaged problem is the difference between life and death... But you do you...

 

[treasurehunter]

@JohnN you are missing the point.
The point is with the energy potential those batteries have ,and if by any unforeseen event a short is caused, quality built or not, they will catch on fire with a very intense heat and they are not extinguishable.

I am not saying that those batteries are not quality and built with quality material.
The physics of the lithium ion battery has not changed or been improved in case of a short. You short a lithium ion battery and it will catch fire.
All the protection is installed after the battery pack itself.
So any improvements in battery protection stops at the bms. After that you are left with the battery itself.
The whole body of the battery is the negative side and only the top button is the positive. These are separated by a mere 2mm. And the entire negative body is only coved by a very thin pvc shrink cover.

Because of the physics of the lithium ion battery, why take a chance for any reason for a potential fire hazard in a sport that is already dangerous enough when there is an alternative. Battery outside of suit.

Also just because something has not happed yet does not mean it never will.
Many companies have had excellent products just to get a bad batch of components and have major recalls or caused deaths.

 

[Superlyte27]

OOOOOhhhh insults. Isn't that the last refuge of the hopeless.

Lol, I couldn’t care less how you live your life. I gave you good solid info. Use it or don’t. We both hope I’m not right.

 

[Whitrzac]

The whole external vs internal batt is purely a theoretical argument, because its a non issue.
If your external batt floods and catches fire youre not getting it off before it melts a hole in your suit, and gives you 3rd degree burns. Most people have issues reaching the switch, much less unbuckleing and sliding a d ring, triglide and canister off, while its on fire.

 

[MrBlenny]

Both my wife and I have the Santi heated vest and they work great. We also have the Santi full heated suits and gloves (we dove in Antarctica and the Arctic) and so far, all of the Santi heated undergarments have worked really well. You'll also need a good battery...Santi makes a small one for the vests...we have UWLD batteries for the suits. You just need to keep the battery under 160 wh for any airplane travel.

Thanks for the input, I went ahead and ordered the Santi vest, thermovalve, and 15 Ah LM canister yesterday evening. Looking forward to having a non-shivering dive buddy this winter!

 

[MrBlenny]

MrBlenny, maybe a heated shirt would be a better option then a bulky heated vest (in Europe Heizteufel, Yellow Diving or Smart-Tex would be good examples).

@Michael, still happy with your Heizteufel shirt? Still without heated gloves?

Those are interesting. Heizteufel looks a bit like the DTEK option I was looking at, but alas, I already had pulled the trigger when I saw this. I'm still going to give it a good look, as I am thinking of getting something later for myself. 90min dives get chilly for me in winter.

 

[MrBlenny]

The whole external vs internal batt is purely a theoretical argument, because its a non issue.
If your external batt floods and catches fire youre not getting it off before it melts a hole in your suit, and gives you 3rd degree burns. Most people have issues reaching the switch, much less unbuckleing and sliding a d ring, triglide and canister off, while its on fire.

On the topic of runaway batteries that others have mentioned, we dive with EAN32, no separate Argon for inflation, so not only is a runaway batter bad news in and of itself, the suit is filled with plenty of O2 to sustain combustion.

As far as removing an externally mounted, combusting battery goes, yes, it would not be trivial to do quickly, but I'd give it a shot with a Z-knife, something I would have no chance of with an internal battery pack. Also, the majority of the battery is surrounded by seawater, which is great at absorbing heat and reducing burn severity.

 

[Chris H]

Both my wife and I have the Santi heated vest and they work great. We also have the Santi full heated suits and gloves (we dove in Antarctica and the Arctic) and so far, all of the Santi heated undergarments have worked really well. You'll also need a good battery...Santi makes a small one for the vests...we have UWLD batteries for the suits. You just need to keep the battery under 160 wh for any airplane travel.

All of the Santi literature says to use 12V DC. Isn’t UWLD higher than that?

 

[grantctobin]

All of the Santi literature says to use 12V DC. Isn’t UWLD higher than that?

The pack is, but it’s only a constant 12V that hits the end of the controller, so no worries on that front