The battery builders club

How-Tos & Esk8 mechanics
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#7471

No, I cut the nickel to length, chomp corners, tack each piece once, then do back and add welds

#7472

Also nominal voltage for 18650 cells is 3.6v, you want them to be within 0.01v when you make the pack

1 Like
#7473

SO, tell me if this is ok:
this is the charger I’m using:


The voltages above are what I got after the charger claims they’re fully charged (just shy of 4.2V as you can see).
Is it safe to build the pack with them like this?? As in, this charged, or do i need to discharge them to 3.7?
#7474

that’s close; how much am I gonna fuck my pack if they’re .03 difference?

#7475

Whats the voltage of the rest of the pack?

Have you had any incidents happen before while you built packs?

If you balance these at 4.2v and the rest of the p groups are at 3.7v for example, its easier to discharge the 4.2v group then charge the rest to 4.2

#7476

https://bigbattery.com/product/delta-electronics-power-supply/
Apparently this (48V version) is a 13S float charger.
https://www.manualslib.com/manual/37613/Delta-Electronics-Mcs-1800.html?page=20#manual

#7477

so I’m building the pack with salvaged cells that are all around 2.6V. So I’m charging them to 4.2(ish) because this charger I have doesn’t allow me to adjust the voltage I want to charge to. It just charges to what it thinks is full (which you can see from the image above is CLOSE to 4.2 but not quite). I’m gonna wait a couple weeks to make sure the cells hold the voltages, but I wanted to check ahead of time rn to make sure that it’s safe to build a pack with the voltages I got above, So asssuming the cells hold the voltages, I plan on just charging all the cells to this 4.2-ish V, just wanted to make sure that’s gonna be ok.

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#7478

I’m totally noob and the last pack (and only pack thus far)I built @iamasalmon did the welding p-groups for me so this part of the building process is new to me. =/

#7479

If you have that much time get some balance charger or that balancing board from hobbyking for like 7$ its works quite well

#7480

can you show me what you’re talking about?

i have one of these:
https://www.skyrc.com/iMAX_B6_Charger
and one of these:

but I don’t see how these hobby chargers will balance cells without welding them and making a balance lead running off of them? Sorry I’m sort of confused on this process

#7481

I have one of these too:


are you saying just go ahead with welding the p-group and then balance with this later?
#7482

Are there places in the uk that build batteries to spec?
Which would be recommended?

#7483

You could easily do that. Within the p-group those voltages are perfectly fine. They’ll put energy into each other and balance out to one voltage. The probably in P groups comes when you have more voltage difference than 0.1v or so because then the more charged cell dumps energy into the less charged cell, and if it has to dump too much it can spark or cause heating of the cell, which we don’t want.

If you were to put all of those cells in parallel right now, nothing would happen visually and they would just end up meeting somewhere inbetween all of their voltages. Once they are all one voltage, it’s basically just like it’s one big cell, and then after that when you put it in series, you’ll want to charge it up to very close to whatever the other series packs are at so the bms or balancer can balance the remaining 0.05 or 0.1v difference

1 Like
#7484

thanks @ShutterShock well explained! :cowboy_hat_face:

1 Like
#7485

@kook

Do you use this for your Liion packs?

2 Likes
#7486

YUP

love it!

but fukk bangUUd in the butt!!
I got mine from amazon

3 Likes
#7487

So should I kick my BMS and brick chargers out the door?

3 Likes
#7488

sorry ! miss-readed… I use it for LIPOS

I’m building a solution for LiOns

3 Likes
#7489

Whats the solution kook?

#7490

a DC Power Supply Adjustable volts and amps

1 Like