Vehicle alternator as recharge option (and some other q's)

Okay, so where I live, importing items is a high risk as we have a very corrupt government, and also corrupt customs. I know this from personal experience where items were imported, never received, but tracked up to customs and they laugh when you get upset. Anyways, so importing motors and psu's is a high risk.

WRT wiper motors, I can get new ones from automotive sellers like Midas etc, for most current vehicle brands. Would a new vehicle like the new opels wiper motors work for this purpose? I had a look at them, most look kinda the same, but none gives technical detail, only said 12v, and part nr.

Secondly, old server psu's are non existing here, so I'm forced to take a different route to solve the power delivery problem. I'm thinking of using one car battery per motor, which totals to 3 batteries in parallel. Then, to charge these, I have vw golf R alternator. To spin the alternator at 2200 rpm at least, I have a stand alone 220v motor which I can hook up via a pulley system. I know this may sound ghetto A.F, but it's the best, quickest, and cheapest option I can think of atm, unless I buy 6 brand new 2000w corsair PSU'S and link them to double the amps, but that's going to cost a small fortune.

Would this idea work? Or are there better alternatives out there somewhere?

I can get new 12v 30a cctv psu's for very cheap if that may be a viable option.

http://m.bidorbuy.co.za/item/246649845/12v_30amp_CCTV_Power_Supply.html

It will work but its not a good method to connect batteries in parallel and then charge them together because they will discharge and charge at somewhat different rates and you can ruin batteries that way if any get overcharged.

@BlazinH thanks for the reply. It's good to know, then I shall take a different route. The 12v 30a cctv psu? Would that work if I use 1 per motor?

I'm not sure why you're thinking you need 3 batteries anyway when one should do the job. One automobile battery provides more than enough current to run all your motors. Its just a matter of whether you can keep it charging fast enough. I use one battery and a 100amp charger myself and run all of my motors that total 3000 watts and can potentially pull over 300 peak amps without any problems.

Schweeeet man. That's perfect. Adjusting the pulley ratio of the alternator I'm able to run it at 7-10 000rpm, which might do the trick and only using 1 battery. Thanks mate. Any idea if the new vehicle wiper motors would suffice?

Sorry but I haven't a clue when it comes to wiper motors.

No worries, I'm gonna buy and try them. If it doesn't hold up, then I'll source motors from 18 wheelers

I was going to say something about being worried about the _constant_ draw from the battery.. but then.. if you're talking about a 2DOF build, then you're talking about 2 wiper motors, which is what you'd find on a car, being powered by that battery... so that's likely not a problem. Your mechanical AC-DC bridge of motor and alternator would work (and I've heard of people removing the alternator rectifiers from that sort of setup to change back to AC at a different voltage and/or frequency - with hefty efficiency losses, but it's done), but a good battery charger as mentioned would be a much quieter option and probably quite a bit more efficient.

Okay, yes, I do have a 30 amp industrial battery charger that I'd rather use instead of the alternator setup. Thanks for the reply.

30A * 12V = 360W, so assuming your motors are less than 180W each then it should theoretically be able to keep up with them running constantly (though the charger likely puts out more like 14.5V or so, which is where a fully charged 12V battery usually sits). They're not going to be pulling peak power all the time though, so even accounting for inefficiencies, you should be fine with that, I'd think. I'm no expert, though.

The battery charger is an Einhell 30/100. 6V, 12V, and 24V at minimum 30 amps, with 100 amp @ 5 seconds peak (for a starting option). So then it definitely should work.

you could use a computer power source, i don know how much current does the motor need , but these kind of sources provides different levels of voltages (3.3, 5 12, 24)

AFAIK normal psu's are underpowered for these applications, that's why server psu's are recommended, because of the high amperage rails.

Correct, tho I have seen some PC PSU's used in the past.

Agree with you ... just adding (5-6) 10000 uF capacitors parallel to the 12v output to handle the peak current and you're ready to go