Charger Power Supply from old PC ATX PSU

[MGone]

Another late night post from me...

I stumbled upon this electronics tutorial that outlines the creation of a bench supply from an old ATX PSU and I was wondering if doing this as a simple 24v supply would be a good way to power something like the ISDT Q8 500W DC Charger?  Then running a parallel board off of it to get a dual output of approx 250W/channel max

I'm basically trying to find a solid and reliable way to charge multiple identical batteries....probably nothing bigger than a 5000mAh 3s lipo.  2 at a time would be fine. 

At 2c that would be 110W/channel so well within the Q8 range...could I even push it to parallel charge 4 batteries at 2c?

Sorry too many questions...so back to the main one.

Is this a sensible approach to take?  The power supply is 550W I think.

Might it be better to run 2x Q6 Nano's (200W each) instead or should I just simplify it all on go for a 2 channel charger such as the ISDT D2 or even simpler the SkyRC T200 and I don't need to mess around with external PSUs.

cheers

[Gampla]

Be honest with yourself how many batteries do you run at 1 time?

Sent from my G8341 using Tapatalk

[m4inbrain]

15 minutes ago, MGone said:

Another late night post from me...

I stumbled upon this electronics tutorial that outlines the creation of a bench supply from an old ATX PSU and I was wondering if doing this as a simple 24v supply would be a good way to power something like the ISDT Q8 500W DC Charger?  Then running a parallel board off of it to get a dual output of approx 250W/channel max

I'm basically trying to find a solid and reliable way to charge multiple identical batteries....probably nothing bigger than a 5000mAh 3s lipo.  2 at a time would be fine. 

At 2c that would be 110W/channel so well within the Q8 range...could I even push it to parallel charge 4 batteries at 2c?

Sorry too many questions...so back to the main one.

Is this a sensible approach to take?  The power supply is 550W I think.

Might it be better to run 2x Q6 Nano's (200W each) instead or should I just simplify it all on go for a 2 channel charger such as the ISDT D2 or even simpler the SkyRC T200 and I don't need to mess around with external PSUs.

cheers

 

It's never really sensible to charge batteries higher than 1c. Yes, you can, but you shouldn't - you'll reduce their life considerably faster that way. 

 

Yes, you can run a balancing board to charge multiple batteries on one channel - technically. In reality, there's a few restrictions like this only works with equal batteries - not just manufacturer, capacity etc, but also cycles etc pp. I know people who do so, but generally i'm more the kind of guy that argues that if you want to do a certain thing, you buy the thing that's supposed to do what you want to do. I have a four port charger, and charge 4x 4s 6200 at once - at 1c. The batteries are charged in less than an hour. Charging at 2c, to me personally, just makes zero sense unless you're charging at the field via car battery. 

 

Each to his own though, if that's what you'd like to do, you can. 

[MGone]

Only one at a time but we’d probably get though 10-12 packs for me and two boys.  So if I can get recharge down to three hours I’ll be happy. 

[MGone]

Thanks @m4inbrain  I'm not ready to splash out for a 4 port yet, but that sounds like a great setup.  I guess I'd like to get up put the packs on to charge before breakfast and then head out when they're done.  I don't really like the idea of charging overnight and I wouldn't want to keep them charged in advance for too long, so was just thinking 2C might be okay...that was the general consensus I picked up from a number of YouTube channels.

But sticking to 1C lowers the required power I guess, so I have more headroom on the PSU.

Would it be possible to run two chargers connected in parallel so they both get the 24V?

If I'm only connecting one pack (5000mAh 3S) to each charger then I'm only really needing 5x(3x4.2) = 63W from the charger, so maybe an 80-100W unit would be okay.

If the PSU is 550W could I start with 2 100W chargers in parallel and add a couple more further down the line?  At around £25 each for something like the ISDT Q6 Nano it seems like a good way to get 2-4 port charging?

 

[m4inbrain]

4 minutes ago, MGone said:

Thanks @m4inbrain  I'm not ready to splash out for a 4 port yet, but that sounds like a great setup.  I guess I'd like to get up put the packs on to charge before breakfast and then head out when they're done.  I don't really like the idea of charging overnight and I wouldn't want to keep them charged in advance for too long, so was just thinking 2C might be okay...that was the general consensus I picked up from a number of YouTube channels.

 

You can charge them the day before, it doesn't hurt the batteries. You shouldn't leave them charged for weeks, but a day or two is completely fine. Sensible approach in regards to overnight charging, just don't. Always be around (and awake) your batteries while charging. 

 

2C charging generally is fine, it won't blow up the battery or anything - but it'll reduce the overall cycles it can take, for no real reason - you're still charging them 45 minutes on balance charge. I would also not necessarily go by youtube comments (for anything, ever, lol), i'd stick with tutorials etc of people who're in the hobby for decades and are known to know what they're talking about, plenty of them about. 

 

The point here is, it's also fine to over-discharge your battery once or twice, it won't blow up from that either. Yet you won't see anyone suggesting to do so. 

 

I'm not an electrician, as i said, i'm the kinda guy who buys things according to purpose (at least when it comes to witchcraft electricity). I wanted to charge big packs quickly, so instead of charging them at a higher charge rate, i bought a charger that charges four of them at once. In fact, i bought it years back when i technically didn't need that much charging power - but now with two RCs running 8s packs (and the charger now £100 more expensive).. Probably best buy i did in my RC "career". All i do is plug it into the wall, press a few buttons, and then go out with my RCs the next day. 

 

If i were you? I'd get a few Imax B6 AC/DC chargers, done. They're like £20 on the usual webpages, get two (or four), plug them into the wall and be done with it. 80W is sufficient for most stuff, and at £20 a pop they don't break the bank. This also leads to batteries being balanced individually, unlike what you're trying to do where the charger is trying to balance a big 12s pack, basically.

 

That said: this is how i approach things, that doesn't necessarily mean that you need to do that too. It's just that i can't offer different advice. 

[MGone]

Completely get where you're coming from.  I tend to be a 'buy good, buy once' kinda bloke...but also like to recycle things where possible and given that RC as a hobby is a goldmine for tinkering I figured there's no harm in asking questions as it makes trying stuff out less expensive

 

[Gampla]

Completely get where you're coming from.  I tend to be a 'buy good, buy once' kinda bloke...but also like to recycle things where possible and given that RC as a hobby is a goldmine for tinkering I figured there's no harm in asking questions as it makes trying stuff out less expensive [emoji4]

 

Then go ahead build your charging system update us on how that goes

Sent from my G8341 using Tapatalk

[Smoothybb]

38 minutes ago, m4inbrain said:

If i were you? I'd get a few Imax B6 AC/DC chargers, done. They're like £20 on the usual webpages, get two (or four), plug them into the wall and be done with it. 80W is sufficient for most stuff, and at £20 a pop they don't break the bank. This also leads to batteries being balanced individually, unlike what you're trying to do where the charger is trying to balance a big 12s..... 

That's the approach I've taken and like the flexibility it gives. I started with x1 b6 when I bought my first plane, I now have x2 b6 and x2 overlanders. I only currently go up to 4s but with planes, cars, quads and boats all having different batteries, it means I can charge whatever I'm going to need simultaneously on a different charger. 

[MGone]

On 19/09/2020 at 12:18, Smoothybb said:

That's the approach I've taken and like the flexibility it gives. I started with x1 b6 when I bought my first plane, I now have x2 b6 and x2 overlanders. I only currently go up to 4s but with planes, cars, quads and boats all having different batteries, it means I can charge whatever I'm going to need simultaneously on a different charger. 

I'm thinking the same, only maybe with the ToolkitRC M6's...at around £25 they seem affordable and packed with features.

Then hook it up to a home made PSU from server parts.

Two of these maybe?


Although to be fair, they are a little long!!

 

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