I hate FedEx. In the last 5 years I have never had 1 good transaction/experience.
That's a lot of voltage applied to the buck convertor. What if you turn the voltage of the power supply down to 5 volts or so. Will the buck converter still put 100 watts into the cells? It would run a heck of a lot cooler.So its charging at roughly 100-105 watts now instead of 35 watts! But DANG that buck converter is getting warm at 30 amps. 20 minutes in and its steadily at 150* F. The little fan on the bottom is kicking ass and the heatsink seems to be doing well for it. All wiring connections are at 69* F or less.
The buck converter is rated from 20v-70v input, so its well within its capacity, its just very inefficient going from 32v to 3.6v. If I try and turn down the voltage on the power supply, the amps coming out of the buck converter drop though, I tried several different times.That's a lot of voltage applied to the buck convertor. What if you turn the voltage of the power supply down to 5 volts or so. Will the buck converter still put 100 watts into the cells? It would run a heck of a lot cooler.
I would not try to pull 30A from that Buck converter, I usually do 80% max, also keep close eye it since when Buck converter MOSFET failed shorted it will dump 32V to the output.Charging the batteries now. Since I don't have a BMS yet I can't wire them in series and charge, so I am using a bench top power supply (the one Will recommends on his website), set to 32v and max amps, and then using a 30 amp buck converter to step 32v down to 3.6v at 30amps. So its charging at roughly 100-105 watts now instead of 35 watts! But DANG that buck converter is getting warm at 30 amps. 20 minutes in and its steadily at 150* F. The little fan on the bottom is kicking ass and the heatsink seems to be doing well for it. All wiring connections are at 69* F or less.
I'm also charging inside of my Marco toolbox's Hutch. This way if something happens (like hardware malfunction) there's nothing to catch fire lol
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I would not try to pull 30A from that Buck converter, I usually do 80% max, also keep close eye it since when Buck converter MOSFET failed shorted it will dump 32V to the output.
Wow! I have never seen a stud blown off clean like that. That would have scared the crap out of me. Hope you are wearing eye protection.Any ideas to fix this one? Maybe mill the terminal flat and drill/tap a new hole? The battery still measures 3.31v.
It was really quick, and since it blew the stud off, the cable I was attaching disconnected fairly quickly, so no other damage was done.Wow! I have never seen a stud blown off clean like that. That would have scared the crap out of me. Hope you are wearing eye protection.
It could not hurt to try to mill and tap and use a helicoil. You do not want to go more than 6mm deep from the top of the terminal. I know 6 or 7 is common with EVE cells. Of course you will want to capacity test that cell after you have tapped it. My guess is there is nothing wrong with it so hopefully it can be saved.
Of course the terminal height will not be the same as your other cells. You could use a short cable for an interconnect. Personally I am a fan of braided busbars.
Yeah I thought about that, I don't know the structural integrity inside the battery and if it will just push through, as we will need to use more than likely several thousand PSI to press it in all the way.If I understand you correctly, I don't know how much pressure can be applied to the terminal. Pressing a stud might cause the whole terminal to press down. In case you didn't know, the studs are pressed into the pedestal. And then the pedestal is laser welded to the cell terminal.
I like the way those studs are mounted too. How many amps do you plan to draw from the cells once you have them in service? My concern is the surface area of the pedestal. Others are concerned about that as well and as far as I know no one has run a test to see if they can carry large current. It doesn't mean they can't, but no one knows for sure as far as I can recall.
Yeah no problem. I can do bus bars up to 1/4" thick, and I can even offer tin plating.I'm proud to be the first person to suggest a group buy of copper bus bars from Lt. Dan!
How about it, Dan? Would the shop allow it?
Yeah no problem. I can do bus bars up to 1/4" thick, and I can even offer tin plating.
I'm running a 48v system. And the only reason I am hesitant to go to a DC to DC converter is because none of them are smart charging. When talking with battleborn, we determined that they would hold the 12v Batteries at too high of a charge voltage for far too long, and cause battery degradation. Hence the suggestion for the 120v victron 10a smart charger, because it is a 3 stage charger and won't hold it at a high state of charge for extended time.
Another thought I have, which I am completely ignorant when it comes to this, but what happens when you try and turn a 12v starter with a 48v battery? Will it burn it up?
I did find out onan recommends 450 cranking amps to start the generator.
Yeah just give me the length from stud to stud that you need, and how wide you want your bus bar.Cool! You willing to do custom lengths - I'm working on a project now where I have a couple 3 cell "fat side to fat side" EVE280's to parallel and a couple 6 cell.
I was going to bug the local marine shop we get bus bars from but they are busy and grumpy with all the spring boat work going on. Seems a ton of lithium retrofits going on.
Yeah just give me the length from stud to stud that you need, and how wide you want your bus bar.
Just know I can't compete with China when it comes to this stuff ? the 12"x12" piece of 1/8" Copper i bought was $100 alone, but it should make around 28-30 bus bars.
Lt Dan, if I recall correctly, did you make your bus bars for EVE 280Ah cells?Yeah just give me the length from stud to stud that you need, and how wide you want your bus bar.
Just know I can't compete with China when it comes to this stuff ? the 12"x12" piece of 1/8" Copper i bought was $100 alone, but it should make around 28-30 bus bars.