Bought this Thermalution 15m Surf Series about when I started GPSTC, 6-7 years ago (2011 to 2012) for $300 AUD (www.thermalution.com/Product_water_surf.html) and of course it's a whole lot more bucks now:-(
I remember the day it was delivered taking a plunge on a product no one had heard of and knew about. At the time I was windsurfing a lot more over winter than I am now and I remember freezing my arse off regularly during these winter sessions.
I've only used this vest maybe a handful of times over 5 years, last used 13/6/17, under my wetsuit being a 4-3mm. So this is a lightly used product but still going strong. The tighter the fit the better for distribution of heat to your back where the elements are located. There is some heft from the x2 lithium ion batteries but they are not overtly heavy and they are located on each side just under your arm pits.
There are x3 heat settings and indeed I've never actually run out of juice when using this as even on the lowest setting I've not used it for more than 4 minute bursts as I'll get too hot if on for longer. The hottest setting gets hot quickly and is a good quick heat booster after you've just fallen into the cold cold water which sometimes water slides in from the top of my wetsuit!
The dongle switch seems to be the right length which is easy to use whilst sailing, and doesn't seem to bang around enough to scone you in the head. The quality is I suppose is okay and speaks for itself in still being alive after 6 years. The battery lead contacts are solid, no corrosion evident and still watertight when you connect it all up. There are x3 pin connectors that do require deft lining up but otherwise I've not bent any pins. The battery units are well constructed with no corrosion evident on my casual inspection. I'm the sort of guy is if it works I wont pry to much more. I'm surprised the company is still going so indeed if I needed new batteries they have them:-) They also do many more variants of heated vests for a wide range of activities.
Would I pay the amount they're asking for now, alas probably no. Did I pay to much back then, hell no. Has it been worth the bucks, hell yes. This is a hot water bottle on steroids with the user getting the option to use it when needed and supposedly can last for 90+ minutes:-) I've never used it more than 30-40 minutes in a session, only using it in bursts as the heat is trapped inside the wetsuit fast. I love toasty warm, its just getting out of my gear that my tootsies get a wee bit blue I don't like these days!
(these are my own opinions with no incentives from anyone for this write up - just thought I'd give a shout out for this niche product)
Thanks for the review. AFAIK, Thermalution is the only game in town now - both Quicksilver and Rip Curl discontinued theirs. The Quicksilver shop guy told me "they are trying to work out how to make them cheaper". The Rip Curl guy - "the wetsuits are warm enough".