I can possibly give you a very good reason why computer power supplies are handy to keep around! If you ever blow up your solar charge controller, and you can fix it yourself but need spare parts! There's a good chance that the computer power supply might have what you need! I have a car Solar DC to DC charge controller which can charge from the alternator and a solar panel, always choosing the solar panel first if available, well mine was blown because the house battery was disconnected! There's these things that look like transistors but in fact are double diodes! They are not cheap and I don't know if they are genuine since coming from China but while watching a computer power supply repair video I spotted similar double diodes in it and thought to myself that I have heaps of these things in my garage! And at least I know that these components are going to be genuine! I just have to now make sure that their datasheets have the minimum requirements! I had some spare parts right under my nose and didn't realize it! Dah! The both basically are power supplies!!!
ok, so could you also get 3,7v (12 - 5 - 3.3) or (reuse the voltages AGAIN to create even more combinations thereof? Like 2x (12v - 5 -5 ) +12v = 12.8v which equals to 3 times 4,26v which Is 3S LITHIUM CELL fully charged
@@OffGridGarageAustralia Hey Andy i dont think you ended up doing this vid on the buck converters? I created an interesting project recently that allows me to charge from the power port in the back of my car without blowing the fuse. I am using step up CC and CV regulators from ali express around $7 each and i set it to 6 amps into the battery it does require the addition of a fan tho but at 4amp it doesnt anyhow it might be an interesting topic - charging lithium from step down or step up regs.
@@carlh2007 Thanks, I've shown this in future videos and we have used this method quite a bit with step down and step up converters before we started using 'real' chargers.
Hey there, can I use the +3.3V Output (with high current) to "precharge" a 3,2V LiFePO4 Battery? Wouldn't it charge about to 80 % and then lower the Current to almost 0? So it would be verry save with no posibility to overcharge? I have a 400 Watt Compurter Power Supply that shows me 30 Amps on the 3.3 V Cable continous output. I thought after a capacity test this would be a way to charge the empty cell as soon as possible to a stage that it is healthy to the Battery. Wish all of you a happy new year and many educational videos like this. Michael from Germany
Older PSUs required a dummy load to keep them turned on but I’ve yet to come across one that needs this resistor. Just need to do ‘soft’ switch on. You can adj the output voltage if you can find the feedback resistors and modify the values but there are limits. Typically the 12v can be adj to 15v before overvoltage protection cuts in.
@@OffGridGarageAustralia have you seen this guys video where he makes a 2400w 24v power supply for charging batteries out of 2 cheap rack mount 1200w HP psus? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-d7lF1sIgIlA.html
There is only one single blue cable for the -12V connection. This is limited to 0.8A only in most power supplies. So +12V and -12V will give you only 0.8A all in total.
If you need massive amps @ 12V, grab an old powersupply from a router/switch from Ebay. The Cisco 4500 for example has multiple options with massive 12V power: The 1000/1300W powersupply can deliver 84A, the 1400W version 12 V @ 113.4 A, the 6000W version does 183A.. They are cheap, approx 25 USD for the 1300W version With a 1Kohm resistor you can start the power supply, see ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7MQglbyH2TU.html If you have some electronic skills, you probably can reverse engineer the feedback circuit and modify it to provide for example 14V output. If it does provide CC at high loads you can use it directly as a charger for a 4S configuration. (If it does enter hickup mode upon exceeding its rating that won't work, unless the wires are size to limit the current to exceed the max, but I think they will become pretty hot in that case) On Ebay I see for example PWR-C45-6000ACV for $29,99. That one is able to deliver 183A.
Interesting, thanks for the lead. What would be the best way to step up the voltage to 14-15v for Lifepo4 charging however? Any idea if the high-pots are adjustable to accomplish this directly?
