LiFePO4 DIY options

[TimC]

Dan from Freely Roaming...

I just watched his, Battery Upgrade Part 1 video.

There's a little man on my shoulder that just said, "I hope our AGM dies soon!" The little sh**.



Tony

Tony... "Die AGM die!"

And I was so happy this spring when my almost six year old AGMs where going strong. Geez!

[tony.latham]

Tony... "Die AGM die!"

I'm the target of a conspiracy...

T

[Tom&Shelly]

Tony... "Die AGM die!"

I'm the target of a conspiracy...

T

This reminds me of working in the lab. One guy doing serious scientific/engineering research, and the rest of us standing around kibitzing...

Tom

[lfhoward]

This reminds me of working in the lab. One guy doing serious scientific/engineering research, and the rest of us standing around kibitzing...

Tom

As a scientist I can appreciate that!

It’s always good to entertain the scientist.

Please stick around. You all ask good questions and bring up good points that make this battery build better.

[Tom&Shelly]

This reminds me of working in the lab. One guy doing serious scientific/engineering research, and the rest of us standing around kibitzing...

Tom

As a scientist I can appreciate that!

It’s always good to entertain the scientist.

Please stick around. You all ask good questions and bring up good points that make this battery build better.

Glad you don't think we're hijacking the thread! This is very interesting!

Tom

[tony.latham]

I just checked my AGM. The damn thing's showing fully charged on the AiLi meter.



Tony

[tony.latham]

I just snagged 8 of these 78 Ah Lishen units...

Hey, I'm confused. If each holds 78 amps... isn't your new battery going to hold 624 amps? Or am I failing (again) at Ohm's law?

Asking for a friend. I'm not building one. I swear. Honest.

Tony

[lfhoward]

I just snagged 8 of these 78 Ah Lishen units...

Hey, I'm confused. If each holds 78 amps... isn't your new battery going to hold 624 amps? Or am I failing (again) at Ohm's law?

Asking for a friend. I'm not building one. I swear. Honest.

Tony

You're not wrong that 624 amps seems awfully high. The magic there is when top balancing, all 8 of the 3.2 volt nominal, 78 amp hour cells are hooked together in parallel. It’s a low voltage, high amperage pack at the moment. Once top balancing is finished, the cells will be reconfigured into a 2p4s pack (2 parallel, 4 series) that is 12.8 volts nominal, 156 Ah.

[Tom&Shelly]

I just checked my AGM. The damn thing's showing fully charged on the AiLi meter.



Tony

To tell the truth Tony, I want your AGM battery to last a long time! Since I bought mine about a year after yours, if mine lasts a year longer that will prove my contention that charging from the TV doesn't hurt AGM batteries. (Okay, we may also have different discharge profiles, and I don't plan to take mine off of solar power in the Winter, etc.) But I'd be happy not having to replace my AGM battery in the teardrop ever.

Of course, I may entertain myself by building a LifePO battery for the garage, where I have no AC power...

Tom

[tony.latham]

that is 12.8 volts nominal, 156 Ah.

Thanks. I'll tell my "friend".

Tony

[tony.latham]

To tell the truth Tony, I want your AGM battery to last a long time!

So do I. I didn't buy a cheaper one for that same reason.

Now the little sh** sitting on my shoulder hopes it'll freeze to death this winter.

Tony

[lfhoward]

Waiting for top balancing … … … it is up to 3.31 volts, which is the same place it was yesterday … … …

I created a “model” of the back wall of the compartment where the battery will live and sketched the components on it.


I’ve got the main off switch, a big fuse, and a breaker coming off the positive, and the shunt on the negative side. The inverter is the big rectangle below that stuff.

I need to mount the BMS to the front of the box, but those rods are in the way and the BMS has no screw holes in it. I think I remember people using VHB tape to stick BMS’s to battery boxes, but not to wood. I’ll have to see what I can come up with. I have a little of the white ABS plastic sheet left that I could mount there using screws, then VHB tape the BMS to the plastic surface.

[rjgimp]

:surrender:

Dan from Freely Roaming...

I just watched his, Battery Upgrade Part 1 video.

There's a little man on my shoulder that just said, "I hope our AGM dies soon!" The little sh**.



Tony

We are seeing a weakness in the force, its all going according to the plan.

Stay strong, Tony! Stay strong...

[lfhoward]

:surrender:

Dan from Freely Roaming...

I just watched his, Battery Upgrade Part 1 video.

There's a little man on my shoulder that just said, "I hope our AGM dies soon!" The little sh**.



Tony

We are seeing a weakness in the force, its all going according to the plan.

Stay strong, Tony! Stay strong...

“You don’t know the POWER of the dark side…” —Emperor Palpatine

[tony.latham]

“You don’t know the POWER of the dark side…”

I know I'll build one. I have to. But hopefully, it won't be for four or five years. But by then, I might be able to find the parts for a flux capacitor on Alibaba?

https://www.oreillyauto.com/flux-500.html

And who knows what lithium cells may be going for by then.

Tony