PINNED ZXD2400 Old + New 0-60V 0-50A Power Supply & Charger

[shirley_hkg]

I'll fix it all, before shipping.

[slomobile]

I want the twin supply unit. I can wire it directly to my garage electrical service panel provided there is a means of connecting large enough wire.

My vision is getting worse. I'd like a means to view and control remotely on a much bigger screen. Maybe with a raspberry pi, or via network. Is there English documentation for the control interface so I could hack something together?

[Burgerman]

What advantage does a twin one have?
2 seperate ones side by side takes the same space.

But if one dies you dont end up with a massive case, and a dead power supply to lump about and waste space.
And if they are seerate you can take one to charge your van or test some motors or power something else as needed. While still charging your chair with the other.

Seems 2 seperate ones have many advantages.

[slomobile]

The way I'm building my power walker thing is with 2 battery packs along the left and right frame with open space in the middle. Swappable packs. I want to be able to charge at least 2 at once.
Also, the well pump backup requires 2 powerchairs in series which I ordinarily use on their own. If a storm is coming, I want to get them equalized asap.
I guess you are right that they don't need to be in the same case. Hmm. I'll think about the weight of a combined unit vs the hassle of moving about 2 separate boxes.

I can only get 3kw 240V easily in the garage. But it might be nice to move one into the house occasionally to run on 120v.

Are there any electrical use case advantages of the combined unit? Like balancing 2 12v series connected lead batteries installed in a chair without separating them? 2 bank charging I think its called? But I suppose you could do that with 2 individual power supplies too.

[Burgerman]

If you wire the 24v chair right you can do it with one 12v supply. Like I do in my van.

Theres no advantage to having 2 in one box other than you cant lose one!

I can actually take 6200 watts from any of the double sockets in my room. Just not on a single outlet. Since they are on a ring. A loop fed by a 15A 240v AC breaker at each end. So I can take 30A or 240V from the wall. In any room. It will work safely. But not sure its a good idea. But its unlikely that both will be drawing full power anyway. Because you would need to be using both at 60V DC to make that happen. So less of a problem than you thing anyway.

But I think its overkill. Unless charging a tesla.

I think seperate ones make more sense. Right now theres 2 supplies on my bench next to my computer. Because I use them for lots of different things (hobby stuff). And one near my bed to charge my salsa chair.

Last week only one on the bench, one in my garage charging other chairs with a PL8. And one temporarily on my van.

Lumping a 2 in one version about will be heavy, harder to sit on a seat or out of the way and less flexible.

[shirley_hkg]

I missed the
USER MENU.

[Burgerman]

I am saving!

[robint]

How do I get one of these? pls
Robin

[Burgerman]

I already have 2. Just PM a freind of this site in hong kong. ShirleyHK that posted the pictures. Dont be scared of HK Dollars theres about a million to the £.

[fishinjunky]

I am saving!

Same here. Its time for me to get one or two. How long do you think they will last lifespan?

[Burgerman]

Well theres a lightbulb in a livermoor fire station thats been on and working for 100+ years. The worlds longest living on bulb...
Some of mine lasted a week. So who can know! I have 2 of them. Use all the time and so far no problem in years. They are made well electrically. So should last a long time. But shit has been known to happen!

[Pierro]

Hi guys! I have a ZXD2400 too. It is one of the series 1. It works great, - thanks to Shirley_hk. Up until now I have only used it as a desktop power supply. Apart from voltage and current, there was nothing to do. Now my original charger for the Optimus2 is defective and I have sent it in for repair.

Now I want to set up my ZXD2400 as a charger by using the 3-stage charging function. I want to do it like Steves1977uk - via XLR - 12 amps.

Which of the circles represents the 3-stage charging function?

thanks for help.

[shirley_hkg]

Yes. The one you pointed to.

[shirley_hkg]

Here is LROBBINS' parameters to fine tune 3-stage charger.

Page 15.


https://www.wheelchairdriver.com/board/ ... &start=420

[Burgerman]

That is a bit ott. Goes into full calibration details etc.

I cant explain in words. But its relatively simple once you play with it.

You can do this 2 ways.
1. Dont worry about 3 stage. Just do a 12A and 28.2V for gel, (28.8V for AGM), CC/CV power supply setting, and charge until current drops to below 0.1A. Or 8 hours at CV voltage whichever occurs first. Best in cyclic use. And is faster. No float required.

2. 3 stage. Charge as above, same current, same voltage, but when current falls to 0.4A drop to a 27.2V float. This is slower and it needs about 8 to 12 hours at float minimum to end charge at 100% full. Best if in no hurry. And getting a battery to 100% matters in cycle lifespan.

[Pierro]

Thank you very much for your help.

One more question: I have these MK batteries:

Do you know the maximum Ah I can charge these batteries with if I charge them directly via Anderson?

I couldn't find any information about it on the Internet.

Thank you very much!

[Burgerman]

AROUND 1/3rd C is where you want to be as a maximum. Around 1/4C is ideal for a balance of service life and affordable charger... So a 25 or 30A charger.

Amps, not Ah though. And they are gel I think. So you want a MAXIMUM of 14.1V per battery (28.2V for 2 in series), and you need to charge them until they reach this voltage, plus 8 HOURS in deep cycle use. At this point float isnt required. But wont hurt, at 13.6V per battery indefintely. (27 to 27.2V.).

[shirley_hkg]

Seems no room for SB50. Be prepared to swap out the XT90, if an Anderson were to be installed.

I prefer the last one. The laid down on its side one.

Have some progress on adding Anderson SB50.

[shirley_hkg]

[jefferso]

This thing is great. It's nearly silent.

Looks like I'm using about 27 Ah in a day just rolling around in the flat, standing a few times and running my ventilator. The charger put in 5.77Ah during a mid day charge and 21.35Ah overnight into the MK Gels in my Permobil F5 VS. That's through the joystick XLR port though so probably losing a fair amount due to resistance.

[Burgerman]

As a rule with XLR charging you will only lose maybe less than 1% due to wiring. Where you lose out is in the time it takes to charge. Because while on charge the natural battery voltage once around 95% charged is dragged high. To maybe 13.4V due to the opposite to peukert. The surface charge is high. So if charging at 14.1V for gel for e.g thats a difference of only 0.7V per battery. So any resistance in the loom, means you might lose a fraction of that 0.7V difference and so less current flows. This means that the bulk of the charge isnt really affected.

But at the poit where it naturally slows down as the battery becomes more charged, then now it slows down a lot more. It may add an extra few hours to the charge compared to say an anderson connector and some more substantial cable.

So it causes a bit time difference. But no real losses. Where there are losses is inside the battery. The higher the charge voltage is, the more that some of the charge energy goes into splitting water into oxygen and hydrogen. So at the last part of the charge, during CV, then the battery wastes some energy getting hotter. The battery is recombinant. Which just means that at low currents, where gassing is slow, the battery recombines these gasses back into water. That process produces heat too. So in the first 80% of the charge its about 99.9% efficient! The last 20% gets more and more wasteful as time goes on. So how much gets wasted as a percentage overall depends on the charge voltage, the battery itself, and the length of the CV stage. But you likely waste 5% on a full charge. Or should I say you SHOULD be returning around 5% more in watt hours that you took out. In order to get a complete charge.

[LROBBINS]

The ZXD also compensates for wiring and connector resistance by raising its output voltage so that the voltage ad the chair comes close to matching what you set.

[shirley_hkg]

How to go to the menus :⇒

USER : press the menu button.

ADVANCE : press menu button for 4 seconds, prompted for password, (default 0000). Press again.

FACTORY : press menu button for 4 seconds, prompted for password, (default 0000). Press 4 seconds to enter.

[shirley_hkg]

The ZXD also compensates for wiring and connector resistance by raising its output voltage so that the voltage ad the chair comes close to matching what you set.

This version has 4-wires mode (switchable), that ensures accurate voltage at ends of wires. Calibration is needed for the first time, to bookmark resistance of the power lines.

With it, we can charge individual cell at high amp.

[Burgerman]

That then works the same as the PL8 does.
It uses the cell balance wires to do the same thing.
When charging 1 cell or all 8 cells, the balance wires (OR THE CHARGE WIRES) sense the cell / pack voltgage during the breaks in the high frequency pulse width charging.

Its switching all the time at one of 3 different frequencies. It measures volts while charger isnt charging every few ms.

So the individual cell voltages at top of page are accurate, and measured during the charger "OFF" periods.
The overall voltage displayed lower down, is the average voltage at the charger required to achieve the voltage at the top if lead or the cell voltages if lithium. Which is why they are not exctly the same and dont match. Although they will get closer as the current falls away.

Read the top one for accuracy! Not the lower down one as it will usually be a little higher voltage but its not the battery voltage... Even when no balance wires are used.

[Burgerman]

Even on lead, the BLUE arrow shows ACCURATE voltage as it is measured during the breaks in the square wave pulse during charge. Its a rested battery voltage. Measured while theres no charging happening at high frequency. In this case its the actua measured voltage div by the number of cells at the battery. It can do this on just 2 wires... But on lithium needs 9 balance wires. As presumed equal cell voltage isnt good enough here.

6 cells x 2.4481V = 14.668V
Average output = 14.713V (So now you can see why they are different!)

The green arrow shows the average charger voltage during the on and off pulses at the charger output. So it will read higher than the cell volts figure times by no. of cells, at the top.

If I put my fancy fluke 289 at the charger output, I see 3 different voltages.
HIGH (during the "on" times)
AVERAGED RMS (average as any normal voltmeter will read)
LOW (during the "off" times). This matches the blue line...

And I can do the same at the battery. And this also shows 3 different voltages. Only the "off" low figure matches the charger off time. The rest are different!
Voltage isnt simple.

[shirley_hkg]

I've made one laying on side , with XT90 and Anderson at the back.

I prefer to stock case one as it's more compact.

[Burgerman]

Very neat!

[Burgerman]

I just ordered on of these newer version ZXD supplies/chargers from Shirley.

These are 0-60 Volts DC, 0-50 Amps, 3000 watts. (same as older ones were, better display, quieter, more connectivity options)

And are either a power supply, which means it can be used as a quality high power capable bench supply, as a charger 2 stage CC/CV charger, or for lead batteries it can be used as a 3 stage charger.

All user configurable. These things are converted from a high reliability 24/7 duty cycle telecoms rack mount supply used in industry. They are electrically very robust and high efficiency. They work on 240V (and at half power on 120V AC systems. 25A DC output instead of 50A).

They can be configured as a 0-120V and 25A clean DC supply too should that be of interest.
I use 2 of these already as lead/AGM/Gel battery chargers at 12A and proper settings and 3 stage (via XLR) to give a superior battery charger than any mobility charger. And at 30A via Anderson. 50A on Odyssey.

I also use them to power PL8 chargers for lithium chairs and lithium/nmh etc hobby stuff.

Rear Panel Connections:
Anderson 50 (120A capable)
XT90 (90A capable)

Front Panel Connections:
4mm banana connectors for bench use on front. (Only use 4mm front connectors for 25A or less).

It is £110 +£45 fast(ish?) shippng from HK. And a bargain! Contact Shirley.

[Burgerman]

What size is the small barrel connector on the front? Is it also DC power? If so then only good for maybe 5A max? Or something else? Ground? Programming? Or voltage sensing at the battery?