I thought I'd take a punt (gamble) on the new model UBEC (switching battery eliminator circuit) at HobbyKing, and see if it was good enough for my HK-500GT heli kit.
Since there is not much info around on these here's a dump of my bench test tonight.
I had a SportBEC 3.5Amp UBEC on hand for comparison too, the numbers I got on the alleged 5A SBEC worried me a lot. Hence my posting the mini-review.

OK.
Grunt, how many amps can it output before the supplied voltage drops significantly (say about half a volt).

With the battery supply set to 11 Volts (like 3S system) I could only get 4.2Amps. The SBEC got hot VERY quick, like too hot to hold in 15 seconds.
Ripple voltage (interference causing stuff) was a hefty 250mV on my oscilloscope.
After about 30 second the SBEC started flashing the output LED (on the 5V output line) and voltage also pulsed. Over heated I'd guess...

On a battery supply input of 21 Volts (like a 5S system) I couldn't get past 4Amps load before output voltage dropped off by a lot. The SBEC got hot VERY VERY fast. I measured over 100 degrees C on the main chip in only about 20 seconds. Ripple voltage was an astonishing 500mV, that's WORSE than on the lower voltage input.

I checked my test setup against the 3.5Amp SportBEC.
I got 4 Amps out of it before the output voltage dropped significantly. Good, since it's actually only 3.5Amp rated. It got hot too eventually, but not as fast nor as high as the new Turnigy SBEC.
Ripple was a very reasonable 40mV at that load.

Other stats.

At 3.4Amps load and 11V input (to be fair for the SportBEC) the measured efficiency of the SportBEC was 72%.
At 3.4Amps load the efficiency of the Turnigy SBEC was 55%
That helps explain the heat !

Not tested was how it handles very fast changing loads (surges), but I only have so much time for testing stuff like this.

I don't have an old 3A Hextronic UBEC on the bench right now, but I think I recall them being very much better than this (the new 5A).

Open for comments....

Edit:
I forgot to mention the differences between the two regarding the way the voltage rolls off under high load.
The SportBec voltage output decays gradually once about 4Amps is reached. The Turnigy/Otter collapses very rapidly when it's reached it's load limit, more like an abrupt shutdown.

So, it's not so good ?

I ordered 4 last week, to be used on 2s...........

Originally Posted by jay1st

So, it's not so good ?

I ordered 4 last week, to be used on 2s...........

Nope, not so good. I think the older Hextronic originals performs better than these.

These are basically the same as the Other 3amp bec's they are 5amp burst (very short bursts)... Stupid lableing....

SK

Originally Posted by ministeve2003

These are basically the same as the Other 3amp bec's they are 5amp burst (very short bursts)... Stupid lableing....

SK

Yes stupid labeling like you said. One major thing is worse though, the amount of switching ripple it has on top of the DC is much higher.

I'd try these... they're not much cheaper, and prob way better... I've used this one with
5 hxt900 servo's on a 4cell, and have never had an issue...

http://www.hobbycity.com/hobbyking/s...oise_Reduction

SK

For anything above

3micro + 1 Mid servo (heli)

5 Micro's like hxt900's (or 4 hs65's)

I'd recommend uping the amp rating to be a bit safer... I use this one on my Trex500 with 3 mid size Digital MG servos, and an Futaba 9254, spartan gyro, and it has never failed me... better to be on the safe side than have a Bec induced brownout

http://www.hobbycity.com/hobbyking/s...BEC_for_Lipoly

If you like castle stuff, they also have a similar Bec with the same specs, and a very similar price....
SK

Originally Posted by ministeve2003

I'd try these... they're not much cheaper, and prob way better... I've used this one with
5 hxt900 servo's on a 4cell, and have never had an issue...

http://www.hobbycity.com/hobbyking/s...oise_Reduction

SK

I agree too ministeve. That UBEC is a good one, in bench tests and in the air. I use the unshielded version in a full house glider with 6 servos and have had no problems.
I also have used them in 450 helis.
I think it would be fine on a 500 size helicopter too. The 7.5A model is a weight penalty that needs to be considered.

It's really safer on the 500 to use the 7.5a one, it's not much of a weight consern on that perticular application... and the 500's use larger servo's.... it's also fine on 45"+ size planes... where you might use larger servos... and a plane that size won't mind an extra ounce or so...

SK

what do you think of these?

http://cgi.ebay.co.uk/ws/eBayISAPI.d...g#ht_651wt_939

thanks

Originally Posted by captaintomo

what do you think of these?

http://cgi.ebay.co.uk/ws/eBayISAPI.d...g#ht_651wt_939

thanks

Good, it's the old design. But surely HK is cheaper, it's their product after all.

Originally Posted by PLMS

Good, it's the old design. But surely HK is cheaper, it's their product after all.

I live in the uk. So after deliveru from hk i might aswell get it from ebay. USA so dang cheap

Hello,
I have 2 questions.
1. Does it come with ferite O-ring as shown in this picture?
http://www.topprops.co.uk/Assets/Tur...0V/SBEC40V.jpg
Mine arrived without this ring.
2. Its said input 8v-26v(2-7cell LiPo) but normal 2s LiPo voltage is around 7-7.5v under load. Can it still operate under rated minimum 8v input voltage? I dont want to risk my model.

Best regards,
S.Ganchev

PLMS,
Thanks for the great info. I definitely think the Otter is 3A w/ 5A burst but label no clearly. When they say "Max 5A", that tells me normal amps is below that. However, your ripple data should be noted. I have the older Turnigy but haven't really stressed it nor do I have test set up and understanding...so far it has been fine.

Can you also check the efficiency if you stay under 3A?

Also, I'm pondering some bigger planes with retracts, flaps, etc...that are advertised as up to 12 servos...yikes. Is there a good SBEC that you'd recommend while still staying fairly economical?

Originally Posted by dude_109

PLMS,
Thanks for the great info. I definitely think the Otter is 3A w/ 5A burst but label no clearly. When they say "Max 5A", that tells me normal amps is below that. However, your ripple data should be noted. I have the older Turnigy but haven't really stressed it nor do I have test set up and understanding...so far it has been fine.

Can you also check the efficiency if you stay under 3A?

Also, I'm pondering some bigger planes with retracts, flaps, etc...that are advertised as up to 12 servos...yikes. Is there a good SBEC that you'd recommend while still staying fairly economical?

I think the older Turnigy (hextronic) are good in the larger sizes too, but I've not tested them to the limits like the new Otter.
12 servos still may not tax a 5A UBEC much (see link), it really depends on what the duty cycle is and how big those servos are. Always do a good 60 second ground test before your maiden flight, moving all servos at once if possible. If the UBEC takes that for 60s it will fly fine too.
http://www.hobbycity.com/hobbycity/s...idProduct=6320
or
http://www.hobbycity.com/hobbycity/s...idProduct=6233