Heating system- battery

[Markos Valsamis]

Ive got the Santi heated vest and thermovalve but would like your opinion on the battery. I'm currently considering:

1) Yellow diving 10ah battery
2) Santi 6ah battery

I am slightly concerned the 6ah battery may not quite be sufficient for 60-90 minute dives (at least not two of them which I would usually do each day). Equally the yellow diving one doesn't seem to have a luminous button to indicate if on/off (whether that's important I don't know practically)?

 

[grantctobin]

See post 3 in this thread: Bottoms of feet cold (drysuit, 39F / 3.9C water)

There’s an attached pdf that goes a bit more into detail.

Long story short: 10Ah is the absolute smallest one should own.

 

[tbone1004]

Ive got the Santi heated vest and thermovalve but would like your opinion on the battery. I'm currently considering:

1) Yellow diving 10ah battery
2) Santi 6ah battery

I am slightly concerned the 6ah battery may not quite be sufficient for 60-90 minute dives (at least not two of them which I would usually do each day). Equally the yellow diving one doesn't seem to have a luminous button to indicate if on/off (whether that's important I don't know practically)?

get the UWLD heat controller, WAY better and safer. More expensive, but you can put a light head on it if you want, and most importantly you actually get the ability to control the temperature up and down which is ideal for ongasing and offgasing control.

 

[RVBldr]

Re: Santi 6A, diving in 48F water in Seattle, I'll turn it on at about the 60 minute point and get about 30 minutes out of it max. Go with 10A min as noted above.

 

[Markos Valsamis]

Re: Santi 6A, diving in 48F water in Seattle, I'll turn it on at about the 60 minute point and get about 30 minutes out of it max. Go with 10A min as noted above.

Is that for the Santi heated vest? They quote 1h15-1h30 run time. I can imagine that's optimistic but 30 minutes seems surprisingly little!

 

[tbone1004]

Is that for the Santi heated vest? They quote 1h15-1h30 run time. I can imagine that's optimistic but 30 minutes seems surprisingly little!

you have to do the math. The vest draws 55W of power. The battery packs are 3s packs with a nominal voltage of 11.1v and assuming 6ah is true and even, then 66.6wh in the pack. 80% of that is usable, so call it 53wh available which gives a 1hr burn. Now what is stupid is that they are using 11.1v packs and direct driving them so what happens is the vest is actually warmer when you turn it on than it is when you turn it off. The heat output of the panels is a direct function of supply voltage and since they are directly driven, that will start at around 12.6v, and end somewhere around 9v. This is the opposite of what you want from a heated vest which is a problem. You are far better off and safer by using a higher voltage battery pack that has constant output and the ability to control that output. That is one of the things that sets the UWLD controller that @Bobby designed apart from everyone else. By using a 5s battery pack, even at a minimum voltage of ~15v when the system will shut off, it is still far higher than the maximum voltage of the Santi/Light Monkey/etc. packs. What this means is that the "high" setting on the UWLD controller is exactly the same at minute 1 as it is at minute 100 offering you predictable heating. It is a lot more money, but you have to ask yourself whether or not it's worth it given the research that has been done about heating profiles.

 

[Wibble]

Best to have a physical switch that you can feel.

They do break for various reasons. A click means it's been turned on even though you're still cold.

 

[grantctobin]

TBone beat me to it. Hr probably absolute max on a new 6Ah battery with 55W vest.

 

[Markos Valsamis]

Thank you all, this is very useful information. Currently with the sort of diving I am doing I don't think I need more than around 45 mins of heating per dive. I appreciate the quality and value of something like the UWLD @tbone1004 recommends, though I have to think whether this is something I require at this stage. If however the Santi 6ah really does only give 30 mins of at best dropping heat, maybe I need to splash out a bit more!

 

[tbone1004]

Thank you all, this is very useful information. Currently with the sort of diving I am doing I don't think I need more than around 45 mins of heating per dive. I appreciate the quality and value of something like the UWLD @tbone1004 recommends, though I have to think whether this is something I require at this stage. If however the Santi 6ah really does only give 30 mins of at best dropping heat, maybe I need to splash out a bit more!

the biggest advantage to the UWLD is the ability to have multiple heat levels where you can start on low and kick it up as you need to which preserves battery and improves comfort. With the biggest canister *comparable wh to a ~15ah battery in 11.1v*, it gives you not only the insane burn time, but also the ability to put a canister light head on the same battery which is a wonderful thing indeed.