making a battery

[jflorey2]

It is my responsibility to learn what I need to know before I start working on any DIY project, and its my own risk. And its my job to make sure I have the proper equipment to do whatever it is safely.

Well, good for you; that's the right approach at least.

So let's start with the basics. Why do you want a lithium battery for your car radio?

Is it because you can't supply the energy (i.e. power over time) that the stereo needs? If so, you need a bigger alternator first.

Is it because you can't supply the peak power (i.e. your voltage is sagging during audio peaks) that the stereo needs? If so, you will be better off with a big capacitor, or a very small, low impedance battery.

Or is it something else?

[J.P.M.]

If I had a friend that knew anything, I wouldn't have came here to bother you guys. Trust me. But if I need to leave or have too I will.

A person is known by the company they keep.

[SunEagle]

It is my responsibility to learn what I need to know before I start working on any DIY project, and its my own risk. And its my job to make sure I have the proper equipment to do whatever it is safely.

Fine. You have accepted the risks involved with your project. All I ask is for you to mention those risks so that others do not just jump in without first knowing there could be some dangers.

[ahdiofreak]

If someone comes onto this forum with an idea that they have no experience or understanding it is our responsibility to make sure they do not do something that can hurt them or others.

Building a battery (any chemistry) from parts without a background in the science can be very dangerous to the novice.

One wrong action could cause a fire or an uncontrolled release of energy from a storage component.

It is my responsibility to learn what I need to know before I start working on any DIY project, and its my own risk. And its my job to make sure I have the proper equipment to do whatever it is safely.

[ahdiofreak]

Building a battery is not something you can do without some knowledge and experience. Without that, you risk damaging the cells (best case) and a fire (worst case.) I'd recommend two approaches:

1) Find a friend with lots of experience/knowledge and have him build it. You may have to buy him lots of beer and/or pizza.

2) Sell the cells and get a battery like the Thundersky that comes built-out as a 12V battery.

If I had a friend that knew anything, I wouldn't have came here to bother you guys. Trust me. But if I need to leave or have too I will.

[ahdiofreak]

Gosh the naysayers on this forum...

This is pretty simple tbh, and LiFePO4 is basically the safest battery chemistry going, so don't worry so much.

You'll need a 4S setup. This'll get you to ~13V. To do that you have two options:

1) 7 4S cells in parallel. You'll need to balance all of the cells in series, so you'll need 7 balancers.

2) 7 cells in parallel, connected in series 4 times. You'll only need one balancer here, however you'll be trusting the individual cells in each parallel set to balance each other. Truth be told, I wouldn't worry about this in such a cheap pack. You can always pick up replacement cells if you kill any.

Balancing's controversial. Plenty of people don't see it as necessary, suggesting you bottom balance the pack instead, charge them until the first cell reaches 'full', and then use these two voltages as your 'top and bottom' thresholds, assuming the batteries will deteriorate more or less in line with each other. You've got a small pack here (about 56Ah) and I'd be inclined to do it like this too. Alternatively, build out the option #2 pack and get a single active balancer (https://www.aliexpress.com/item/3S-t...950876697.html) which will just keep on balancing the pack forever.

Alternatively, get a BMS that'll do it for you. If your current draw isn't huge you could do this, but depending on how utterly absurd your audio setup is, this might not be an option.

Good luck!

I will look into the active balancer, thanks! Even though these cells are cheap to replace and easy to get at the moment, I don't want to risk damaging any of the cells. At my level of car audio, there can and will be a high amounts of discharge going on rapidly. So a cell or more (especially lithium, have you seen vape batteries explode?) leaking or exploding, in a vehicle is not safe lol It could damage my equipment, or even worse catch my car on fire. A BMS would not do good with car audio, but I do plan on getting some cell logs to monitor each bank so I can see whats happening.

[ahdiofreak]

I did not know they made class a amps anymore for cars! Did you get a Krell and a inverter?

They make class a/b amps for full range and class D for bass. And bass is what im mostly worried about because it draws the most current. I do not know what a krell is and no I don't have an inverter

[jflorey2]

It is will be used as a battery in my car stereo setup. I got the cells for a good price, so they can be sold easily if im not able to use them since I did purchase them without actually having a plan.

Building a battery is not something you can do without some knowledge and experience. Without that, you risk damaging the cells (best case) and a fire (worst case.) I'd recommend two approaches:

1) Find a friend with lots of experience/knowledge and have him build it. You may have to buy him lots of beer and/or pizza.

2) Sell the cells and get a battery like the Thundersky that comes built-out as a 12V battery.

[SunEagle]

Gosh the naysayers on this forum...

This is pretty simple tbh, and LiFePO4 is basically the safest battery chemistry going, so don't worry so much.

You'll need a 4S setup. This'll get you to ~13V. To do that you have two options:

1) 7 4S cells in parallel. You'll need to balance all of the cells in series, so you'll need 7 balancers.

2) 7 cells in parallel, connected in series 4 times. You'll only need one balancer here, however you'll be trusting the individual cells in each parallel set to balance each other. Truth be told, I wouldn't worry about this in such a cheap pack. You can always pick up replacement cells if you kill any.

Balancing's controversial. Plenty of people don't see it as necessary, suggesting you bottom balance the pack instead, charge them until the first cell reaches 'full', and then use these two voltages as your 'top and bottom' thresholds, assuming the batteries will deteriorate more or less in line with each other. You've got a small pack here (about 56Ah) and I'd be inclined to do it like this too. Alternatively, build out the option #2 pack and get a single active balancer (https://www.aliexpress.com/item/3S-t...950876697.html) which will just keep on balancing the pack forever.

Alternatively, get a BMS that'll do it for you. If your current draw isn't huge you could do this, but depending on how utterly absurd your audio setup is, this might not be an option.

Good luck!

If someone comes onto this forum with an idea that they have no experience or understanding it is our responsibility to make sure they do not do something that can hurt them or others.

Building a battery (any chemistry) from parts without a background in the science can be very dangerous to the novice.

One wrong action could cause a fire or an uncontrolled release of energy from a storage component.

[phazaar]

Gosh the naysayers on this forum...

This is pretty simple tbh, and LiFePO4 is basically the safest battery chemistry going, so don't worry so much.

You'll need a 4S setup. This'll get you to ~13V. To do that you have two options:

1) 7 4S cells in parallel. You'll need to balance all of the cells in series, so you'll need 7 balancers.

2) 7 cells in parallel, connected in series 4 times. You'll only need one balancer here, however you'll be trusting the individual cells in each parallel set to balance each other. Truth be told, I wouldn't worry about this in such a cheap pack. You can always pick up replacement cells if you kill any.

Balancing's controversial. Plenty of people don't see it as necessary, suggesting you bottom balance the pack instead, charge them until the first cell reaches 'full', and then use these two voltages as your 'top and bottom' thresholds, assuming the batteries will deteriorate more or less in line with each other. You've got a small pack here (about 56Ah) and I'd be inclined to do it like this too. Alternatively, build out the option #2 pack and get a single active balancer (https://www.aliexpress.com/item/3S-t...950876697.html) which will just keep on balancing the pack forever.

Alternatively, get a BMS that'll do it for you. If your current draw isn't huge you could do this, but depending on how utterly absurd your audio setup is, this might not be an option.

Good luck!

[goodoleme]

I did not know they made class a amps anymore for cars! Did you get a Krell and a inverter?

[ahdiofreak]

It is will be used as a battery in my car stereo setup. I got the cells for a good price, so they can be sold easily if im not able to use them since I did purchase them without actually having a plan.

[Sunking]

Yea, I kind of suspected something like this might happen from reading the OP's first post.

He is a Stoner. Pass the bong please.

[J.P.M.]

This is funny stuff.

Yea, I kind of suspected something like this might happen from reading the OP's first post.

[BoloMKXXVIII]

It will be very difficult for anyone to give useful feedback without knowing what you are planning on doing. Having a detailed plan should be the first step before purchasing anything.