Practice run to see if i am on the right track?

Hello Everyone,

I am preparing for my first venture into Lifepo4. I have held on to my FLA long enough......

Rather than make my 8 x 280AH Eva's my introduction, I thought that I would order up the BMS that I intend to use and some cheap surplus Lifepo4 cells and build a small 24v pack to practice on.

I came across a warning that if you mistreat these batteries you can let the magic smoke out and there is no available technology to put it back in.............

I am considering the 32650 cells that BatteryHookup.com has for $3.25 each and either a Daly or the BMS talked about here (Oversolar??).

Another question... As I am likely to only do this once, can I safely solder tab on to save buying/building a spot welder?

Thanks Everyone.

S.

not sure about any smoke, I did get some 280ah cells... due to my ignorance, i did manage to get a balloon out of 1 cell when I was charging it independently . No smoke.

Pnw_steve said:

Hello Everyone,

I am preparing for my first venture into Lifepo4. I have held on to my FLA long enough......

Rather than make my 8 x 280AH Eva's my introduction, I thought that I would order up the BMS that I intend to use and some cheap surplus Lifepo4 cells and build a small 24v pack to practice on.

I came across a warning that if you mistreat these batteries you can let the magic smoke out and there is no available technology to put it back in.............

I am considering the 32650 cells that BatteryHookup.com has for $3.25 each and either a Daly or the BMS talked about here (Oversolar??).

Another question... As I am likely to only do this once, can I safely solder tab on to save buying/building a spot welder?

Thanks Everyone.

S.

Click to expand...

I like this approach!
No idea about soldering vs spot welding though.

This guy, Jehu Garcia has lots of videos on building batteries with the small cells, which I like a lot:

Just my opinion, but you're eventually intending to build a bigger Energy Storage Bank using LFP, therefore if you don't want to take the Big Leap, I'd suggesting starting with lower capacity LFP cells to build your first battery... I'm unsure if BigBattery carries loose LFP Prismatic cells. You'll gain the experience & confidence to take further steps. Different chemistries all have their own peculiarities and requirements, LFP actually is the closest match to FLA basic profiles and hence why it's so well supported by the hardware.

Steve_S said:

Just my opinion, but you're eventually intending to build a bigger Energy Storage Bank using LFP, therefore if you don't want to take the Big Leap, I'd suggesting starting with lower capacity LFP cells to build your first battery... I'm unsure if BigBattery carries loose LFP Prismatic cells. You'll gain the experience & confidence to take further steps. Different chemistries all have their own peculiarities and requirements, LFP actually is the closest match to FLA basic profiles and hence why it's so well supported by the hardware.

Click to expand...

Perhaps I could order up the BMS that I intend to use and some cheap surplus Lifepo4 cells and build a small 24v pack to practice on.

Did you read my post ?

Anyone have any experience soldering instead of spot welding?

Anyone??

I built my 220ah 4s lifepo4 with 160x 32650 cells. I tried soldering with 3 different solder irons but was unsuccesful. The max wattage of my solder irons was 60 watts. Even after using sandpaper to scuff up the cells, the solder wouldn't stick. I had to buy a tab welder (malectrics 12 volt for about 100 dollars) . That worked excellent on those cells. It made quick work of the build. I never had problems before soldering the 18650 cells, which is how I would build using those cells.

But I have seen builds with those cells 32650 and 26650 where they were able to actually solder them, but might require a high wattage solder iron.
The cost of the tab welder didn't go to waste, I now use it also on my 18650 builds. Upfront is a expensive cost, but its a tool you will use again if working with cylindrical cells. It makes the job so much easier.

Seems like if I was gonna start into a small-cell project like this without the spot welder tool, I would probably a just bought these kinds of cells:

I researched what you are doing for a couple or three months before settling on my 280Ah Lifepo cells.

Soldering will NOT work in the end. Period. Every SUCCESSFUL user of those batteries you are planning to get used a spot welder.

Yet one more reason I went with the larger cells.
Hopefully this helps.

There are little $30 spotwelders on ebay, David Poz has a video using one with 32650 cells on his channel, doesn't look that difficult (but it is an irritating additional purchase if you won't have other uses for it).

Looks like a cheap spot welder is going to be the solution. $31 from China or $40 from a US seller.

Then I can tab my $26 worth of batteries.......

Thanks for the input Everyone.