the Ofna 's fan does the same thing not an issue and I guess you can't judge a book by its cover the apperance probubly explains its cheaper price

any idea on a decent (able to run the hyperion duo at full power) 240v compatible supply? can be up to 15 or less,

also, ive got an antec earthwatts power supply, which ive pulled apart gotten the 2 12v inputs and was wanting to knwo what would ahppen if i connected the 2? it would provide 40+ A like that (2 19a rails)

ryan

Up to 15 or less what?

The hyperion duo is max output 360W. Assuming 80% efficiency (about average for these things) u need a 450W PS.

The duo can take up to 28V input, making your usable power supply cheaper. you could get a 28V power supply capable of delivering 16A

Or if you wanted to stick with something more compatible with other chargers, a 13.8V that can hold its own at just over 32A (say 35 to be safe).

Or, best case is to get something variable. Doesnt need to be CCCV power supply like the mastech ones everyone loves so much, but something like this
(less than half the price of a cccv 30V/20A here, note the aussie link, would be a lot cheaper in the states) would be more than ample for all your power supply needs.

15v, sorry!

yeah, i looked at those supplies, but wondered, can they supply the full 20A at 30v?
if they could it would be awesome. it would allow me to charge my batteries without a charger... hmm. cheaper too.

would that work, id be charging in 4s2p, so even if it did try and pull the full 20A it would be perfect. i could just set it on 15v or so, and wait for the amps to drop (is that right, or is there another step they use with their HUGE supplies over in the USA!)

sorry for sounding so noobish. its cause i am :(

Yeah they can supply the full 20A at 30V.

The one I posted you CANT charge batteries with, because it doesn't have the constant current function like the mastech power supplies do (they are a lot more expensive for that reason).

:(

is there any way of getting the cccv chargers in australia or is it just too pricey

You have to be really careful with those CC/CV supplies if using to charge batteries directly. One wrong setting and bye-bye lipo! And it makes it harder if you have different pack "S" sizes. A true lipo charger has additional safeguards to detect cell count and memory profiles to store several settings. Convenience and safety comes at a price.

To set up one of those CC/CV supplies, you would enter in the max current to charge at (1C rate), and then a voltage limit of 4.2v x the number of S cells (for lipo) or 3.6v/cell for A123. This voltage setting is the most important and the one that can cause major issues if you mess up.

Many/most computer power supplies have a 125/240v switch on the back panel to select what you have for mains.

And you have to remember that chargers have efficiency losses (typically around 80% efficient). You have to take this into account when figuring the current you need. If the charger has a 250w limit, that is 20.83A @ 12v. But, figuring in efficiency means you need 26A @ 12v. And since you generally don't want to run things at their max, I usually figure in another 10-15%. So, that's almost 31A @ 12v. Also, the 12v line will drop under those kinds of currents so the charger will try to pull even more current to compensate for the lack of voltage. Being able to tweak the output to ~14.5v would reduce the current required substantially. But since it's hard to tell which PS unit will have the ability to tweak the output a little higher, I would shoot for a higher current PS, something like 35A. This page can help select the right size PS for your needs.

Paralleling the output of a dual 12v rail supply may or may not work. I had one where if you did that, the supply got quite hot quite fast and shut down. IMO, it's best to get a single supply type. Here are just a few seemingly decent ones:
35A: http://www.newegg.com/Product/Produc...82E16817182010
35A: http://www.newegg.com/Product/Produc...82E16817148009
28A: http://www.newegg.com/Product/Produc...82E16817101520
25A: http://www.newegg.com/Product/Produc...82E16817170017

hmm. if im spending more money, id rather get a power supply DESIGNED for this use...

and i wouldnt ever try charging lipos on the cccv psu's. only a123... are there any other 1/2 decent brands available fron HK or the like? (or that dont weigh a ton and cost $100 just to ship it here??)

sorry for hijacking... oops!

nah, I've seen a few mastech (or rebadged but the same) go on ebay for about $120usd, usually costs around $110 to ship it also, still less than half what they want for one here.

Heres a CCCV charger, looks like a rebadged mastech. It's a 50A model too, which would have to add to the price a bit

Anybody have any experience with these power supplies?

20, 30, 40 Amp Power Supplies

@George16

I've got one of them, T2M branded (a french hobby distributor),
Work fine,
the Fan behind do accelerate his speed in fonction of the amount of current used. The box is quit large but it's light.

The only flaw I found that the front led does not always turn on when i turn on the PSU

its a very good price ...they dont give you very much info and no company name you can research.....

I did some searching on the net and found this ham radio switching PS and got some very good reviews from the radio guys which have higher demands then RC expect to pay about $80 minus the shipping charges and since it only weighs 4 lbs it shouldnt be more than $10

http://www.jetstream-usa.com/jtps28.shtml