Electronic load for testing - any thoughts on ET5410?

[pickworthi]

I have been thinking of building my own restive load device. I don't need anything fancy, just enough load to discharge a 10S Lipo battery pack safely, although some flexibility would be nice. For context, I'm in the UK, and have a street legal e-bike. Staying legal means I'm in a power range that the USA users on here would find hard to live with (250 - 500 watts approx)

I see lots of threads on here about such load devices, ranging from repurposed hairdryers, water heaters to halogen bulbs. While I could go about building something, I've had a look for something off the shelf, and found this:
https://www.banggood.com/ET5410-Pro...Electronic-Loads-400W-150V-40A-p-1613467.html

Looking through the manual, it looks like it could do what I need - up to 400W by the looks of things. That is a bit lower than my estimated 500W max load but seems serviceable.
It costs more than a resistor load bank I've designed, but not a lot more, and I'd save the time involved, and get functions I could not do myself (CC, CV and the like).

However, I don't have a great deal of experience in using simulated load devices, so I'd appreciate any feedback on the suitability of this device. If people know of better devices that would also be useful.

Thanks.

 

[markz]

https://www.youtube.com/watch?v=V5PZb6HtwIE

https://www.youtube.com/watch?v=y1zQvgytnFg

https://ebikes.ca/shop/electric-bicycle-parts/test-equipment.html

 

[pickworthi]

Thanks for the link to Grin stuff - I'll have a look. Not had good experiences shipping from USA/Canada to UK in the past.

I'm afraid my hillbilly tolerance level isn't high enough to watch the videos through.

 

[markz]

I'm afraid you are missing out. You could actually learn a lot if you check out his other videos, which he has lots but goes into a variety of other departments including disassembling batteries, tools, guns, fixing stuff.

I'm afraid my hillbilly tolerance level isn't high enough to watch the videos through.

 

[john61ct]

I'm afraid my hillbilly tolerance level isn't high enough to watch the videos through.

I was going to criticize your bigotry, but have to agree, 15sec in had to bail

not just the accent but that delivery style, just intolerable.

Can't stand YT in general for information transfer, just write it up post a diagram works much better for me, only want a short video when it's absolutely needed, to demonstrate a procedure or something.

 

[john61ct]

Be sure whatever you choose can also do single cells if you need that.

40A is only 150W limit when voltage gets low.

The ZTE / ZKETECH line gets great kudos from many experts

EBD-A20H being a common example

 

[pickworthi]

Thanks for the pointers,
The EBD-A20H looks really nice. Unfortunately the 30V limit is just short of what I will be using it for most of the time.

I searched for ZTE and ZKETECH and my searching skills must suck worse than I thought. I didn't find anything in the 42V category I need. Several quite expensive and nice looking devices did show up, so I did spend quite a while weighing up options.

Since no one here has responded on the ET5410 yet, I thought I'd do a little public service exercise and bought one. Less than a weekly grocery shop if it turns out to be rubbish.

First surprise was that it arrived (via Banggood) nine days after order was placed - with Christmas and New Year in between. Parcel said it was shipped in Abu Dhabi - not seen that before, but whatever works I guess.

The device itself appears well built. Supplied with a European IEC cable (aka "kettle lead" for UK viewers). Unearthed with a travel adaptor. I don't know why suppliers bother with leads for IEC plug devices, but that's another story. Threw that away and used one of my (many) grounded UK IEC leads instead. A small switch on the back selects between 110V and 220V supply - it was set to 220V, but worth checking.

A printed user manual was provided. It is a comprehensive description of how to set the value of every setting the device has. What it does not do is explain what any of the value settings actually do (beyond the function headings like "Constant Current", "Constant Resistance", "Battery Test" etc). So that is for the user to discover, or have prior knowledge of.

In use, experimentation with the aforementioned values is complicated by the use of only two not very helpful error messages: "unreg" and "OVP!". So, perseverance is the name of the game (for me, at least).

I have now used the ET5410 to discharge a few batteries, 3S and 10S. I used CC, CR, and the Battery Test mode (which can be either CC or CR). The device does what it says, in that it will discharge at a load of your choosing up to it's limit of 400W. That meant 10A CC for my 10S packs, which is fine for my intended usage. The fan kicks in very noticeably at 300W, and produces a nice little shed warming flow of warmish air.

Conclusion so far is that the ET5410 is not rubbish. It works for my very limited use case, as stated at the top of the thread. For me, it's a good price point. I'll continue using it and report back after more extensive use.

If anyone gets a ET5410 and can't make any sense of the settings I'm happy to share what knowledge I've gained in this exercise.

 

[pickworthi]

Follow up after seven months of use.

After getting the ET5410 I built myself a 600W resistance load from an IKEA desk fan heater. That allows me to do full stress tests on my newly built batteries, which I wanted to do to be sure I built them right.

However, the ET5410 has been getting a lot of use in my shop, and I've found it very useful. I would suggest that for someone who wants an adjustable load at a cheap-ish price point, it is a good choice.

It's main drawback, and something I only realised after using it for some time, is that it does not have separate input ports for voltage sensing. This means that it can't be used for so called "four wire" discharge tests, and the voltage reported is lower than actual. Thus, for accurate discharge comparisons this is not the device to use.

Having said that, the flexibility provided is useful for other things. Some of the things I've been doing are:
- Popping fuses, using it's short circuit mode. This allows testing of the current that a fuse will blow at for example, or for testing short circuit protection in any circuits you build if you want to test that. Limit of 400W applies (i.e. only combinations of V and A that are under 400W).
- Providing variable load to test circuits. I found it's current measurement was pretty accurate - at least as good as the several hobby watt meters I have.
- Discharging batteries to storage levels if they come back from a ride unused/slightly used.

Just in case someone is thinking this would be a great device to plug into an iCharger 4010DUO as an external load.... it doesn't work. I suspect that the iCharger does some testing down the discharge port that gets "interfered with" by having an electronic device plugged in. You probably all know that, but I was dumb enough to have a go

My summary would be - its a good, reasonably priced variable load device that is useful for casual or occasional users. It's more flexible than a fixed resistance load. But, if you are going to do discharge tests, I'd recommend finding a model that has separate voltage sensor inputs.

 

[john61ct]

excellent contribution.

If you feel further inspired, a write up on how you would rig an accurate CC load discharge test

as high current and low voltage as possible, ideally 1S

would be greatly appreciated

 

[pickworthi]

If you feel further inspired, a write up on how you would rig an accurate CC load discharge test ...

I would feel like such a fraud given the esteemed contributors to this forum. I'm just a another hacker

 

[pickworthi]

I thought I'd post this here because it would honestly not have occurred to me to do this until I saw someone on YouTube doing it.

Picture below shows two ET5410 loads connected in parallel to a pair of Dolphin batteries, also in parallel, under discharge test. Each ET5410 contributes 250W of load, thus giving me my required 500W continuous discharge for my test. A Siglent desk multi meter is providing logging of voltages to a laptop on the top of the tower (not required - just to explain what's going on).

I had got fixated on looking for an electronic load that would provide 500W of load, completely missing the fact that two would work in parallel, thus allowing lower rated loads to combine to provide higher loads than each could handle individually.

Obvious I know. But something in my brain didn't switch on that possibility until it was shown to me. I guess being electronic loads made me nervous to fiddle. Anyway - hopefully this gives someone some inspiration.

 

[LewTwo]

I thought I'd post this here because it would honestly not have occurred to me to do this until I saw someone on YouTube doing it.

Thank thee .... I just ordered one of these as well (via a slow boat from China).

Why waste money on an “Expensive Desktop DC Load tester”. Simple answer is I had already wasted money on a “cheap” battery tester and quickly burned it up due to the lack of protection circuits (it was a 180 watt unit that I accidentally turned above that limit …. magic smoke). I also had to have a Low Voltage cutoff board inline with that unit. I decided the wiser choice was to spend more money to get a unit with the extra bits built in.

Question: Have you tried the PC software for data logging?

Software download: https://www.easttester-cn.com/uploads/DC-LOAD-software-V1.07-11.18.rar
Manual PDF (English): https://www.easttester-cn.com/uploads/ET5410-ET5411-Programmable-Single-DC-Electronic-Load-User-Manual.pdf

 

[pickworthi]

Question: Have you tried the PC software for data logging?

No, I have not tried any computer interface with these.
For my main use case, I am hooking two up in parallel to get a constant power load. I then use other equipment (desktop multi-meter, current clamps etc) to get any data I need.

Note that they do not have four wire capability, so any voltage they report is skewed by cable resistance and current.

If I want accurate discharge data I use my iCharger - as described here:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=112842

 

[Hillhater]

That seems like an expensive , overkill for just dumping 500W ....when you could just use a few $10 hair dryers or even a coil of wire in a bucket of water !

 

[pickworthi]

That seems like an expensive , overkill for just dumping 500W ....when you could just use a few $10 hair dryers or even a coil of wire in a bucket of water !

I'm not suggesting anywhere that other people do it.
I have the equipment, and so I use it.

Buckets of water have poor data gathering characteristics.

 

[john61ct]

Yes just getting back down to storage V is entirely different from benchmarking SoH

 

[DogDipstick]

I use a bank of 1700w, 240V max, Tempco Strip heaters. I have 30 of them in parralel. 33 Ohms each. On a server rack, on a dolly, serviced with some big switches, heavy wire, and fused input terminal. I consider 240vDC the max, even thought I am sure I could go higher.

They can get red hot, and do, when loaded above 200v. Certainly. I have fans blowing on the top four, or so, stripheaters.

https://www.globalindustrial.com/p/tempco-finned-strip-240v-t1-19-12l-1700w

I also have five 3000w ceramic, half an ohm ( 0.5 Ohm) , Ohmite resistors. I think they are 3000w each. They are about the size of a Arizona aluminum can each. They are those squiggly nichrome wrapped around a ceramic core: spiraling. They love being red hot.

I try not to waste the energy though, I usually regen back in to the battery banks fueling the datalogger.

Here is a pic of it loading up a ~8000w discharge test on a 72v battery on a very cold day in the garage.. (Lol.. Ambient 34* F). I set up the load resistance for the test that day: sometimes I use five, some times ten, some times more, in parallel. Depending on the test that day.

Just in case someone is thinking this would be a great device to plug into an iCharger 4010DUO as an external load.... it doesn't work.

This DOES work with my Powerlab 6s-32s charger by Revolectrix... but.. you have to trick the machine. Machine asks for " Regen battery input" or "Power supply" when you first turn it on... and... If you are running off the regen battery... choose " DC POWER SUPPLY" when first turned on ( even though it is still on the battery DC bank), you can put the resistances across the positive and negative from the Powerlab input right after you star the CC phase of the discharge... ... and it will let the resistance pull the entire current, happily datalogging the discharge. It will not error out.

There was a thread describing this on Helifreak Forums, when the Powerlab first came out and people wanted to get the whole 40A discharge power out, datalogged: but were fueling the charger with small capacity bank: Discharging 6x ( ~5000mAh? ~6000mAh?, ~6s to 8s? 16s? Up to 32s? big heli packs) lipos in parallel on pigtails... Trying to dump 1000wH of lipos into a 500wh lead acid regen battery to store the batteries after the day of flight : Or did not have a regen bank large enough to carry the whole (input) load without complying and reaching the top voltage the charger would accept:.. It would throttle the discharge when it sensed its regen battery as " full".. but is ok with placing a dummy load across the terminals if you need to ( set to switchmode, not battery bank), and still datalogs the channels to spreadsheet. If/when you trick the charger into thinking a dc switchmode power supply is there.

Look up " Revo-Kelly" on Helifreak:, he was a Revolectrix company rep that told us how to do this.

Just a FYI.

 

[Hillhater]

That seems like an expensive , overkill for just dumping 500W ....when you could just use a few $10 hair dryers or even a coil of wire in a bucket of water !

Buckets of water have poor data gathering characteristics.

Sure. ...but you said..

..........I then use other equipment (desktop multi-meter, current clamps etc) to get any data I need.....

If you are using external equipment, how you load the pack is irrelevant as long as you have a constant load.

 

[pickworthi]

Yeah.
If you go back far enough in the thread you will see I'm not into hillbilly solutions.

Also - good luck drawing fixed amount of power across a whole discharge with any of the hairdryer etc solutions.
And, plugging in, switching on, and setting desired load is a lot quicker than trying to marshal 20 or more hairdryers.

Of course, you do what you do.