Revolectrix

[785boats]

I guess that's why they call us the Lucky Country down here in the land of Oz.

2 x 3s & 2 x 2s $20.00 shipping (Fedex)
2 x 3s $17.00 shipping (Fedex)

No customs, no duty, no brokerage fees, no taxes. Yet.

[Peter A]

I guess that's why they call us the Lucky Country down here in the land of Oz.

2 x 3s & 2 x 2s $20.00 shipping (Fedex)
2 x 3s $17.00 shipping (Fedex)

No customs, no duty, no brokerage fees, no taxes. Yet.

Similar to NZ, we only pay tax (GST) on anything over $399 (NZ), so even a big order with a devalued invoice is all good!

[Gary]

Ok this is what I found.I am sure I will get beat up for this but here goes. On average about 1,800 --2,000 rpm more than my Thunder Powers...46,500rpm and is more than I have ever seen. Voltage drop was one volt less and ripple about 1.8 max for what ever thats worth. Batteries warmed to 90* as I always do with lake about perfect as always. Boat picked up 6 mph over its average and tested many times.
At half the cost of Thunders I am sold on them for my boat. Only have old vid for some viewing fun and with the guy fishing it killed my day after one pass!
https://www.youtube.com/watch?v=fkKN...ature=youtu.be

Even more testing. Found that pre heating batteries to 100*+ made an even bigger change in rpm and is now around 47,500. I will have to drop the prop a little and see if it picks up any more speed. Here we go LOL !!!!

[kfxguy]

What are you using to pre heat the packs?

[Gary]

To prevent heat in the packs? Or to preheat the packs?

[montymike]

Pre heat packs.

[Brushless55]

I always let mine sit out in the sun on race days

[Pitts]

Even more testing. Found that pre heating batteries to 100*+ made an even bigger change in rpm and is now around 47,500. I will have to drop the prop a little and see if it picks up any more speed. Here we go LOL !!!!

As an approved manufacturer/ supplier to the Australian Government, my systems supplied to the ADF, when using Lithium Polymer, must keep the batteries constantly between 20 C and 30 C (27 C optimum). This was not just a request from the ADF, but a requirement from the battery manufacture, and is still relevant today.
Any lower in temp increases internal resistance, degrading the battery. This is why a lost model left connected, and left overnight with the temperature dropping, will swell the foil "bag" housing the electrolyte gel. The gel emits a gas and although it looks like the dreaded heat "puff", it will not combust; it may burst (although rare), but wont combust. Heat lowers this internal resistance, but excessive heat stresses the battery. Excessive heat on the other hand can cause the dreaded heat "puff" and combust.
Since first switching to Li-ion in late 1999 we had a terrible time keeping the cells at the correct temperature to induce conductivity. The release of lithium polymer cells a few months later, allowed for stable temperature control because of the electrolyte added to enhance conductivity.

I'm certainly no expert on LiPo's, and other manufacturers may have different techniques nowadays, but this is what we had/have to comply to, and it's worked flawlessly.
Since this time, I have always ensured my RC batteries are between 20 and 30 degrees C, and as close to 27 C as possible, just before, and while in use. I still have and use original packs from 1999 and 2000, and have never had a pack failure (I did however swell a pack from plugging it incorrectly using the horrible "Micro Deans" plugs).

[tlandauer]

@ Pitts,
Thank you VERY much for this info!
This is why I love this Forum, one can learn so many things!

[montymike]

Yep...

[montymike]

A friend of mine used to swear by heating them up by running the boat slow before he punched it.

[grsboats]

There is no doubt that pre heat Lipo batts improve performance and decrease IR so for this task this is what you need: http://www.hobbyking.com/hobbyking/s...g_12v_DC_.html
I've been using this gadget when temps are below 25C.Gill

[Pitts]

@ Pitts,
Thank you VERY much for this info!
This is why I love this Forum, one can learn so many things!

Thanks tlandauer.
As we know, there are advancements in technology at scary rates, so things are probably a little different with other manufacturers. I have no doubt that some manufacturers read threads like this, so it would be good if these people "in the know" dropped in with their take on it all.
Another interesting piece of advise I was given by "our" LiPo manufacturer was to store them in a refrigerator at 5 or so degree's C when not in use. They also said it was fine to store them fully charged this way, so I have been doing this for years, without any problems at all.
I also have a small 12V car cooler/heater which I have fitted a thermostat set at 30 degrees C. It is also plugged in to a mains power timer set to turn on two hrs before I expect to leave the next day, so the night before I am going flying/boating, I place all the LiPo's I'll need in this cooler/heater, and by the time I load the car the batteries are ready; I just pick it up and put it in the car. It stays warm most of the day, and I have put strips of velcro along the outside of it, so my used LiPo's get stuck to that. No confusion, and still just one box to carry!!!.
Like I said though, I'm no LiPo expert, but this advise has worked for me...

[montymike]

Cool gaget

[Pitts]

There is no doubt that pre heat Lipo batts improve performance and decrease IR so for this task this is what you need: http://www.hobbyking.com/hobbyking/s...g_12v_DC_.html
I've been using this gadget when temps are below 25C.Gill

When HK released this for sale, I thought this is a great idea, but it has a minor fault. To give the batteries good heat soak, you would probably need a few of these warmer bags to do all the LiPo's; meaning it's just not big enough. This of course depends on how many LiPo's, and of what size, you take with you. Hence why I like my Cooler/warmer as it has a 14 litre capacity and fits all my LiPo's I need for the day.
The HK warmer is still good though...