Thread: High Current 12 Volt Power Supply

$400 for a new battery? Surely if you aren't using it in a controlled environment you could just buy a N70Z new or second hand for less than a 12V power supply? 30A AC lighting transformers are common enough, perhaps you could parallel 4 of them, but you still need a rectifier that can handle the load.

That's a massive amount of current. With a large battery, it would be completely flat in 1 hour. Does that sound about right? It's quite a lot!

If you cater for 120A at 12v, that equals 1440W. 1440W at 240v is 6A, so a 240v powerpoint could supply enough power OK, however finding a AC-DC convertor capable of that is likely to be VERY expensive IMO. Probably a lot more than $400.

Originally Posted by Mr Whippy

................Is such an animal available to do the job, and would it be cost effective?

Dave.

There is undoubtedly a device capable of doing the job, but at what cost ?. To provide a stable supply that can deliver from zero to 100 Amps plus is a very expensive exercise.
A battery is the obvious choice, and it would have to be a bloody good one to cost $400 . What's wrong with a normal car battery ?, 100 Amps is niether here nor there. Even the starter motor in a small car will draw more than 100 Amps.
The important question is for how long does the battery have to sustain this load ? If it's only a short period then to use a small car or sealed battery might be OK.
What's it say on the side of the old battery. ie. specification. Presumably some sort of sealed lead acid battery, how many amp hours (capacity). Might be written as eg. 20 AH @ 20 hour rate or something similiar.
The OEM (original equipment manafacturer) of the lifting device could typically quote $400 for an 'original' replacement for a battery really worth a quarter or less of that amount if bought elsewhere.

IMO steer away from the idea of a stand alone no battery power supply. The device will have it's own built in battery charger (presumably), just replace the battery.

Deano

Storage batteries are just that... Devices to store lots and lots of electrons, and let them out in vast numbers when required. When not required, the charger slowly pumps more of them in to replace the dead and worn out ones.

Need more info regarding the length of time the motor is running under load... a minute or two? 10 minutes? - How long between each use?

x2 on the N-70 route.

I only purchased this machine yesterday. As for my $400 cost it was actually $360. I just rounded the cost. This machine is a one person vertical lift. When operated it would only take about 15 seconds to get to the top. Probably similar for coming down, although I reckon that it would use much less currant as it has help from gravity.

Info on the battery. I have not yet removed it, but picture shows info on the top cap. Although it is 130Ah the book says that it should be 160Ah.



A picture of the machine



Dave.

Certainly a mean looking machine, how high does it go ? Probably should have its big battery, but suck it and see with a N70 as suggested. Worst case you'll be stuck up there and won't be able to come down.

Deano

Seeing as there's a mains plug, what amps does it charge the battery at? It could be capable of providing much of the power already.

gel and SLA batteries are not ideal for what you're planning i the current draw is going to be 100A,

if your going to do it off of 12V (and Im surprised its not 24/36V) youd be best off with a good car battery in the 500cca range with at least a 10A charger.

if the charger is good then all you need is a battery and Id expect you could get it workable on about a $250 budget (covers modding clamps and covers as well as purchasing a good battery.)