Advise toward a decent enough 1000W or 2000w switching psu :) - Page 1
Forum section: electronics / beginners

author: New Nubby
author_rank: Contributor
timestamp: September 16, 2022, 10:08:16 am
content: Hey guys,I thought about buying this behemothhttps://www.isdt.co/x16.html?lang=enRC charger. But and a big butt, the cost outweighs, logic of getting a different RC charger with the same output minus the internal supplyAs the x16 versus, a p30/q max ( almost matches the output ) and getting a separate psu for it. About a 1000W or a 2000W power switching power/sine wave/variable outweighs the gold plated ISDT x16 lol. Which a heck of lot cheaper with two 1000w or one 2000W. Need a 35A/40A or above with highest voltage can get away with with min of 34v. either two 1000w or 1500w/2000w.That's why I am asking for advise for a decent enough or not to expensive ( if it has decent protection and quality caps etc.. ). I know meanwell is a good brand. Though if can get away with another cheaper but decent brand. Cool ). Though don't mind paying up to $300 or more for a good 2000W supply. But there are cheap 2000w server grade ones that are bargains as ex server supplies.I know you can get cheap server power supplies on ebay or elsewhere be it HP or a trusted brand with 1000 to 2000w cheaply. But wouldn't know what seller or where or which to get. So advise welcome for a power supply and then go for the substantially cheaper charger with a power supply. That has the same charge power/current as or near the x16, i.e the P30 ( dual charge is 800W not the full 1000w each ).Again the x16 is way way too overpriced, goes for $850 to $900 just ridiculous. Knowing you can get P30https://www.isdt.co/p30.html?lang=enwith Maximum Parallel Charging power up to 1500W or the Q MAXhttps://www.isdt.co/qseries.html?lang=enat half cost of the P30, just takes little bit longer to charge 8 lipo's.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 16, 2022, 10:34:42 am
content: Server power supplies are not suitable for battery charging. Modification is possible, but requires deep understanding on how the supplies are designed.Or are you asking powering a cheaper charger which only has a DC input? If yes, then old server supplies are a good idea, or indeed Meanwell does decent supplies, go for it.IMHO, $850-900 is expected price for a 2.2kW li-ion charger with mains input, not ridiculous at all. Parts cost alone for such a product is beyond $100 and they are not sold in millions so after NRE costs, the profit margin is quite thin.

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 16, 2022, 11:14:47 am
content: Quote from: New Nubby on September 16, 2022, 10:08:16 amplenty to choose from in ebay au, just make sure you know how to power them ON independently bofore buying...https://www.ebay.com.au/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=server+power+supply&_sacat=0i purchased 2x Dell 750W PS-2751-5Q, combined power 1.5KW for $25.. another choice is you check for china brand mining PSU, i also bought a 2KW version for less than $100 for my current PC (being sick of cheap 500W PSU that keep burning within months). whichever you want to put your trust on.

author: New Nubby
author_rank: Contributor
timestamp: September 16, 2022, 02:05:59 pm
content: Yes the ISDT x16 is way way to overpriced for a rc charger with internal psu.Look at Mechatrommer's post about how cheap ex servers are ie even 2000w. And in answer to Mechtrommer yea DC input, most if not all rc charger are dc input. All the cheaper rc chargers are DC input. Not many have ac and dc. And the ones that have ac inputs too. Are extremely low wattage like 50w or 100w or 200w and near 200w ones you looking at $300 plus. But their DC input translates to 400w, 500w to 600w. And ac is 50/100w to 200w max depending on how much you are spending. But i think most know.Not worth the cost of a low wattage inclusion of ac ( its more a play thing to have ac/dc rc chargers for the ac part). Also thank Mechtrommer for being awesome!Also "IMHO, $850-900 is expected price for a 2.2kW li-ion charger with mains input, not ridiculous at all." it is very expensive when you can get a DC Q MAX at 1000w/30w and a cheap ex server psu for about $10/$30 to $100. The parts are not worth that at all. As the internal psu are cheap as chips if ex server or even switchable psu and the x16 loses lead acid ability and about 5 different battery chemistry charging capability.So it charges only 3 chemistry types of batteries thats a bit ...yea. Look at the reviews Siwastaja, absolutely everyone agrees it just way, way to overpriced. That's why hardly anyone reviews it unless it was given to them free by ISDT which all are. Its a luxury item, then anyone with sense. Again look at Mecha's prices of ex servers and throw a 120/150 Q MAX lol.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 16, 2022, 04:41:56 pm
content: Well, obviously a dismantled, used unit which has no commercial value will be cheap. Of course there is no way to compete against that price by designing and selling new products. What's the point?I'm driving a car which I bought for 790EUR and it's doing fine. But I won't complain about new cars costing 20kEUR and saying this is "ridiculous" because of the cost of the car I'm driving.Safety Extra Low Voltage DC input charger is much easier and cheaper to design and manufacture than mains AC input charger. The difference is just huge. The reason most hobby RC chargers are DC input is exactly this, to push price down and let the users deal with whatever DC supply, including reuse of old PC power supplies.

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 16, 2022, 05:28:26 pm
content: Quote from: Siwastaja on September 16, 2022, 04:41:56 pmi guess ac input charger is just a specialized ac to dc psu (offline stepdown, a simplified version of those server pc psu) feeding the dc to dc balance charger. and i agree on your points about used car vs new car. those cheap used server psu in ebay were once costed an arm when they were new, so 500-1K cost of KW branded and new PSU is normal imho. used item is cheap, but if its broken in short time, we lose our small investment, the only leverage is knowledge to fix, if we have any.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 16, 2022, 06:21:25 pm
content: Quote from: Mechatrommer on September 16, 2022, 05:28:26 pmNo need for such cascade design, it is possible to design the off-line AC - DC supply to act as the charger, i.e., have a controllable current limit (CC-CV). In this sense, total component cost in such "expensive" product is less than if you buy a server power supply and then a separate DC-DC charger. The only point in that server power supply thing is the economy of scales, plus the market of surplus / used supplies, so you get bang for the buck.For absolutely lowest component cost, one buys a cheap server power supply and modifies it by adding adjustable constant-current operating mode, plus li-ion balance charge controls, totally avoiding the extra DC-DC stage. But as I said in the initial post, this is not trivial.

author: james_s
author_rank: Super Contributor
timestamp: September 16, 2022, 06:26:41 pm
content: Quote from: Siwastaja on September 16, 2022, 10:34:42 amAll of the best RC oriented chargers are DC input, most guys use modified server PSUs to power them. For stuff in the 1kW+ range they pretty much all will accept at least 24V input so what I've always done is modify server PSUs to separate DC ground from earth ground and run two in series. Loads of RC flyers have been doing this for years, there are large threads on the rcgroups forum detailing modification steps for various PSUs. $800+ is ridiculously expensive for a charger, there is no need to spend more than a few hundred bucks.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 16, 2022, 06:40:39 pm
content: Well, obviously a DIY solution where you combine some basically free or nearly free stuff is going to be cheaper than a finished, integrated product which has to do all the same, while being built from new components. You pay premium for the integration into a single product which does it all (AC to battery).Plus I was talking about modifying a server supplyintoa battery charger, which would involve designing a functional and stable CC mode, plus adding control logic with balancing.

author: james_s
author_rank: Super Contributor
timestamp: September 16, 2022, 07:20:08 pm
content: Modifying a server PSU into a charger would be crazy unless you really wanted a challenge, nice robust and flexible chargers are cheap mass produced items. You can buy power supplies intended for running them off line voltage but IMO it doesn't really make sense to do so when there is a glut of top quality PSUs on the surplus market you can get for a song. Almost everybody at the RC fields with a charger >100W is using repurposed server PSUs to run it.

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 17, 2022, 02:18:45 pm
content: even here in malaysia i've to order oversea some 2Mm away to get some stuffs, so i cant really help you about australia, maybe you can ask Dave Jones. 2KW of power is not for beginner, esp modding one, you need to buy oscilloscope, multimeter, solder etc... but then i suggest you start with small power if you are not familiar, but then if you already know, you will not need to ask. 2KW level of rc hobby is not cheap imho, so i'm not sure why you less appreciation on more expensive well designed product. if you already spent hundreds of dollars on big batteries, you should be more carefull not to blow them up with poorly modded psu. btw, you can get 36V by connecting 3 x 12V PSU's in series. if you are lucky, there will be trimpot inside to adjust to 11.3333V each to get exactly 34V you want, but if you are unlucky, you need to get your hand wet. ymmv.

author: james_s
author_rank: Super Contributor
timestamp: September 18, 2022, 06:34:21 pm
content: Quote from: New Nubby on September 17, 2022, 01:44:11 pmI wasn't really intending it to be a retort, he's a smart guy and contributes a lot around here, in this particular case I just so happen to have direct experience from flying electric RC planes for a decade or so.

author: New Nubby
author_rank: Contributor
timestamp: September 19, 2022, 04:15:00 pm
content: I dont spend hundreds on big batteries. And "why you less appreciation on more expensive well designed product" well i dont mind spending a good amount around $300 on a min 34v and at least 40A PSU. So server psu aside. Whats a good enough switchable power-supply ya'll recommend

author: New Nubby
author_rank: Contributor
timestamp: September 20, 2022, 06:24:18 pm
content: Is this anygood below in the pic for price and is there a decent guide for combing two server psu together, but one that has protection in mind to not blow up your dc rc charger then just straight combing themAlso noob question does the dc charger draw as much Amp's as it needs obviously voltage fixed. Or does it push full total amp depending how you wire it ?And second noob question, Is it complicated to make the amp/voltage adjustable?

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 20, 2022, 07:28:40 pm
content: Quote from: New Nubby on September 20, 2022, 06:24:18 pmtldr... what do you think?Quote from: New Nubby on September 20, 2022, 06:24:18 pmjust connect ones +ve to the others -ve then you have series connection. google electrical series vs parallel connection.Quote from: New Nubby on September 20, 2022, 06:24:18 pmusually pc/server psu have overcurrent or overvoltage protection so not to damage the pc/server. but as usual, warranty void if seal is broken (if you do your own mod, your own risk).Quote from: New Nubby on September 20, 2022, 06:24:18 pmmy imax b6 charger, we can set how many amp we want, if we set to lower amp, the answer is no, if set to max the answer is yes. which one you prefer? i dont have the luxury or the need for a KW balance charger, nor the luxury to test all the surplus psu advertized. do you? tell us then what do you think when you got one.Quote from: New Nubby on September 20, 2022, 06:24:18 pmyes. for noobs they have to learn, for more experienced, it will take time. you can search in this forum few designs. i believe diy balance charger also available in the net. i think my imax b6 was from open source design and later made by china cloner, i could be wrong. i bought it instead of design it diy just because it is... complicated. and takes timenot really helpful i guess but i guess you have to pick the spoon yourself to know how it feels. hint: you need to be more specific and show some effort, so we can know your specific case. asking which brand is good which is not can lead to a long pages of debate, not everybody can buy all the brands, for me, any brands are good esp when you see tag such as "used by Dell or HP" psu, but then used and cheap items can be anything, even my used Gossen MetraHit X-TRA was DOA, need some effort to get it back to life. ymmv. cheers.

author: james_s
author_rank: Super Contributor
timestamp: September 20, 2022, 07:56:46 pm
content: If you want guides on converting server PSUs you should visit the rcgroups forum, there are lots of people doing this there.Every load draws as much current as it needs. The load a charger draws will depend on the power you are asking it to deliver to the batteries. Charging higher cell count or higher current requires more power so the input side will draw more current from the power supply.

author: New Nubby
author_rank: Contributor
timestamp: September 21, 2022, 04:16:42 am
content: Regarding Mecha "tldr... what do you think?" I don't know thats why i asked you guys, as you guys or you have bought them in the past and know the pricing.Also not trying to build a balance charger the ISDT has a balance charger inbuilt. I was trying to to just wire two 2000w and was seeing if the youtube video Josh did was on point ( aside my deep diving into more things which i will do ). I will also once i get one or two will update.I will look up more but how about the can you turn/wire the server psu into an adjustable power ? Also not need to badger me too much "nor the luxury to test all the surplus psu advertized"and badger the about long forum postas look at my username lol.Also are you saying there is an rc group thread on here. Or you meant rc group forum somewhere else

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 21, 2022, 05:00:46 am
content: Quote from: New Nubby on September 21, 2022, 04:16:42 amhttps://www.rcgroups.com/forums/index.phpuse the Quote button..Code:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXX

author: james_s
author_rank: Super Contributor
timestamp: September 21, 2022, 06:55:48 am
content: Quote from: New Nubby on September 21, 2022, 04:16:42 amwww.rcgroups.com