Winch Testing Setup

G'day Chump,

I wouldn't class myself as an expert but I'd imagine you'd need to have a set-up consisting of 2 x N70ZZ batteries (or equivalent), hooked up in parralel and charged by an alternator (say 90 amp minimum). This could be established on a static test bed and run by a relatively small motor (assuming you don't want to mount it in a proper 4x4 vehicle, which would be the best way, so long as you didn't break anything and kill the 4by or yourself of course). Remember that you are going to be dealing with significant forces and it is inherently dangerous. Safety must be your first priority.

Alternatively, you may wish to take your winch to a recognised laboratory (like they did in 4WD Monthly magazine a few times when testing snatch straps and winch extension straps etc). However, I reckon they'd charge you big $$$$ for the job.

Good luck

Roachie

Gaday Chump. I'd suggest using several gel cell batteries in parralell. They accept charge quickly so after the test they could be topped up in 30 to 60 minutes. The number of batteries would depend on the amount of testing required but at 400 amps max load a minimum of two 55 amp hour batteries would work OK. By using batteries on a portable test bench you have the option to use for displays at field days as well. A mains transformer would have to be pretty big to cope (up to 30 amps at 240 volts) and really doesn't give a true indication of the pulling power in a car. If you are after a quality assured test result then a mains transformer would be required to supply a constant known voltage.
Cheers Craig.

Chump,

If you are going to test the winches for current draw under load you would have to have a constant and known power supply.
A alternator driven by a electric motor at a constant RPM charging one N70Z battery. From a strong frame anchored to the ground the winches could be set up one at a time to pull a constant weight. 4WD winches are rated for a pull and not for lifting. A amp meter would be able to tell how hard the winch is working,the more amps the harder it is working.
If you wanted to compare winches then the same set up could be used and the winches would have to be set up with all the power cables and controls that come with the winch.

Best of luck with your adventure and I hope it works out for you. BTW where are you going to be setting up?

Wayne

Chump

The essential thing is to get of any variables that you cannot control.

As you've stated, the applied voltage is the main one.

Unless it's a constant current supply a big mains-driven power supply is not the answer: there, the output voltage would drop at least as quickly as with a typical battery.

What I'd suggest is a battery with the least possible internal resistance - and that will not be damaged by repeated heavy loads.

Craig is obviously thinking alone the same lines, but to ensure a more constant voltage for a longer time I'd suggest AGMs (as these have even lower internal resistance than gel cells). You will need to experiment.

I agree that a couple of 50 Ah batteries will start and run the winch but I believe you will need very much more or voltage drop will mask the results. You can of course start with 100 Ah (although I'd gho bigger) and add capacity of necessary.

If you'd like to post here the cable length and known max winch current (I suspect about 500 amps starting and one third to one half that running) - I'll let you know what size cable to use. Welding cable is perfect for this as it is very flexible and also affordable).

Trust this may help - but get back to me if you need more assistance as i have been very involved in the design of measuring stuff like this.
Collyn Rivers

I guess I should have been a bit clearer by what I meant as testing.

I just need a bench to repair / fault-find customers winches if any ever get returned. Kind of like, OK, heres my test bed. Give me your faulty solenoid. No, it works fine. Lets try something else. etc....

We are not only going to be selling these winches, but also offering servicing and repairs. Rather than take the attitude of just replace any faulty products, then after 12 months see you later, we want to be able to fault a find, and quickly turn around and repair it. Also, it would be good to be able to perform services when needed.

The hardest part of the whole process is the insurance, and working out what constitutes a qualified winch repairer....lol... Still, we are just about there.

Cheers,

Chump

Now it's starting to make sense.....i know why you asked me that question via e-mail last week...
Cant help with the electrical side but if you want a bench to test loads etc give me a yell. I used to haul underground cable for a living and we had a bench for testing the max load on the winches. Then i guess the humble multi meter will do the rest.

quote:"My question is- is it best to use a car battery to power this setup, and charge the car battery as I go, or is it better to buy some sort of transformer? The Amps are pretty high for these units (65 just to turn the thing over, then up to 400 with 12000lb's on the line), and my concern is that I will need to fork out huge money for the transformer to cope with this."

If these winches are to be used on cars then your testing facility should, realistically, have similar power sources as are found in car.

I assume you are not going to test winches all day every day at full load. If you were to test a winch at maximum capacity ( as shown above) for 6 minutes then you drain about 40Ah from the battery. Meaning you should have a battery of at least 3 times bigger capacity to avoid draining it too deep.
If this was the only test for the day, then quite a small (~4A, but good quality) charger should be enough to recharge the battery overnight.
If you do repeated tests in succession, then the alternator battery charging method would be better. Keeping in mind that you need about 2HP electric motor power to drive it if this is supposed to be a bench top set up

Chump.
I have built a device for testing winches and starter motors, I used a transformer from a large welder, I used the original primary winding but rewound the secondary it only had to have about 14 turns. I wound four secondary windings (each 14 T) and conected each winding to a seperate 100 amp diode bridge this way you can have 12V at 400A or 24V at 200A etc. Because the transformer draws a lot of power I used a contacter and press button on the primary to minimise the time on. Eric.

i don't see how mains power would be enough.

*power* draw of winch is 4,800 watts (12v x 400a).

typical 10a 240v outlet gives 2,400 watts. 15a 240v -> 3,600 watts and 20a 240v -> 4,800 watts. factor in transformer and rectifier losses (say 10%) shows none of these will be adequate.

best bet is 3-phase. not sure about the power calc but at a guess it's 415 v * 16a = 6,640 watts. you'll then be up for the expense of a 3-phase transformer.

my suggesstion would be to get a pair of standard 12 v truck batteries (~70 cm long) and run them in parallel. get a big charger to go with it. the lot for less than $1,000.