Jedi new battery finished

[s/v Jedi]

Originally Posted by TheoWjr

Very nice work!
I love it, maybe 'cause it looks somewhat familiar.


Cheers,
ted

Amazing how we both used the same fuse blocks and I have never seen them anywhere else for this same cells as well I think

[NaClyDog]

This entire thread qualifies as "DC wiring / setup" porn.

[rgleason]

Jedi, very nice installation, and its right in the centerline over the keel I think. Ideal spot. Just one thought about this. I would fix a block of wood, spacer or insulator between the second link of the negative bus and that + post that it could hit if something shifted. That possibility makes me a little nervous. Amazing you fit it all in.

[s/v Jedi]

Originally Posted by rgleason

Jedi, very nice installation, and its right in the centerline over the keel I think. Ideal spot. Just one thought about this. I would fix a block of wood, spacer or insulator between the second link of the negative bus and that + post that it could hit if something shifted. That possibility makes me a little nervous. Amazing you fit it all in.

Thank you for the kind words
I’m not sure which spot you mean... here is another picture with fuse covers added... does that solve it?

[rgleason]

That looks like a different bank, I am talking about the upper right negative connection with 2 busbars linked together in Post#44 possibly twisting back against the "+" on the second to last battery. It would not be the full voltage, but it would still be something.

[s/v Jedi]

Originally Posted by rgleason

That looks like a different bank, I am talking about the upper right negative connection with 2 busbars linked together in Post#44 possibly twisting back against the "+" on the second to last battery. It would not be the full voltage, but it would still be something.

Ah, that was posted by someone else.

[TheoWjr]

Originally Posted by rgleason

That looks like a different bank, I am talking about the upper right negative connection with 2 busbars linked together in Post#44 possibly twisting back against the "+" on the second to last battery. It would not be the full voltage, but it would still be something.

Yes, that was a pic of my bank, I couldn't resist posting as it shares much with Jedi's bank. Thanks for the comment. I totally agree and that's a good idea. I'm making a polycarbonate cover now so I'll add a stand-off piece right there to have that protection between the shunt and terminals.
Thanks for the input.

[Simi 60]

Slowly dieing battery bank has forced me to look into this thread as 8x 400 is what we will need if going this way.

I can taste a little bit of sick in my mouth as I stand on the precipice and prepare to jump into the LFP rabbit hole.
Picks up koolaid and prepares to chug it down.

[s/v Jedi]

Originally Posted by Simi 60

Slowly dieing battery bank has forced me to look into this thread as 8x 400 is what we will need if going this way.

I can taste a little bit of sick in my mouth as I stand on the precipice and prepare to jump into the LFP rabbit hole.
Picks up koolaid and prepares to chug it down.

You should not worry that much

So in Australia? Do you know the OffGrid Garage Youtube channel? It shows how to get anything LFP related in Australia. I do recommend to go for Winston instead of the cheaper options for a boat though. I’m sure that Julia Yu will get the cells to you as good as possible. A lot of members went before you and ordered from her, all with 100% success.

I can tell you I paid about US$ 3,200 for the 8x 400Ah cells and that you will probably pay much less for shipping than I did

[s/v Jedi]

Originally Posted by TheoWjr

Very nice work!
I love it, maybe 'cause it looks somewhat familiar.


Cheers,
ted

Man it’s only now that I realize again all the fuse holders and shunt are the exact same as what I did and I never saw that anywhere else

[jmh2002]

Originally Posted by s/v Jedi

So in Australia? Do you know the OffGrid Garage Youtube channel?...

Thanks for the link He has a couple of other channels too on related subjects.

https://www.youtube.com/c/OffGridGar...ralia/channels

[Simi 60]

Originally Posted by s/v Jedi

You should not worry that much

A few vids on YouTube makes me feel a bit better but I can't help worrying if 8x400 to give 400@24v will be enough considering we have 880@24v with AGM now.
I'm guessing it should be as the AGM apparently never got below 80% SOC (20% used)

So in Australia? Do you know the OffGrid Garage Youtube channel? It shows how to get anything LFP related in Australia.

Having a look at some now
He does seem keen on those pretty blue batteries from AliExpress.
If it's a colour thing I prefer the radioactive waste / yellowcake look myself

I do recommend to go for Winston instead of the cheaper options for a boat though. I’m sure that Julia Yu will get the cells to you as good as possible. A lot of members went before you and ordered from her, all with 100% success.

I can tell you I paid about US$ 3,200 for the 8x 400Ah cells and that you will probably pay much less for shipping than I did :thumb

:

And she has got back to me.
Batt price same, freight is a killer - not sure if silver bird or slow ship, thinking it's gotta be a plane.

[Simi 60]

Originally Posted by s/v Jedi

I don’t think a BMS is that important for a house bank at all. Only when one needs to get every bit of capacity out of the bank it becomes critical. Example: my cells have a minimum discharge voltage of 2.5V and a maximum charge voltage of 4.0V. For 8s this comes down to 20V and 32V. If I first balance the cells and then cycle between 25V and 28V, how much out of balance need cells to go to get close to those min/max values? It will probably never happen, but a regular look at a cell monitor will make sure.

So my BMS is more of a hobby than necessity. Anyone who knows how to use a multimeter and bench power supply and with the discipline to regularly check a monitor can do without a BMS.

I am interested in this seeing as BMS is the next part of my "rabbit hole" experience.
If I could do without, as I do look at our battery monitor every time I walk past it, that would be a bonus.
No reason a cell monitor couldn't be added to the same spot.

[s/v Jedi]

Originally Posted by Simi 60

I am interested in this seeing as BMS is the next part of my "rabbit hole" experience.
If I could do without, as I do look at our battery monitor every time I walk past it, that would be a bonus.
No reason a cell monitor couldn't be added to the same spot.

After a full season of use, the difference between the lowest and highest cell is 8mV. I’m not even going to rebalance for 0.008V

I have found another way to monitor for this: with a Victron BMV the shunt has this second voltage sense wire that can be connected to cell 4 and the monitor programmed to do midpoint monitoring. It will then show voltage difference between cells1-4 and cells 5-8 and allows alarms to be set for that.

[fxykty]

Originally Posted by Simi 60

…



And she has got back to me.

Batt price same, freight is a killer - not sure if silver bird or slow ship, thinking it's gotta be a plane.

It will be surface ship and it’s because all shipping fees have gone up over the past year. If you’re willing to wait she can combine your shipment with another one or two as long as all shipments are ending at the same port. That’s what she did for us when shipping our cells to Auckland and the two of us each paid half the shipping.