Silly Question? (Victron Multiplus 3000 inverter install requirements)

[Riverbug]

I'm waiting for my cells to arrive (12v 305ah) so I'm also still in my planning stage. Below are 2 great charts that I always refer to and should help you. For the fuse, I believe you have to select your BMS first. It's also in the Victron literature base on the model you choose. You select the lower of the 2. Class T fuse is the one recommended for lithium. ANL also works. The wire size chart is for 12v so for 24v you divide by 2. I thought about doing 24v but I think I'll be going 2 x 12v eventually. Adding a bit of redundancy in case 1 battery fails for some reason. Hope this helpsAttachment 44801Attachment 44802

There are a few BMS types that are 24v. I would suggest a minimum of 150 amp BMS. The DIY Solar Forum is a FANTASTIC place to learn, but can be a bit technical sometimes.

I can help but I'll need to know a little more about how you plan to run the cells together? You can use a single BMS to run a 24v battery, no need to parallel. How many cells are you planning? 8? 16? 24? As far as for fuse and wiring, you'll expect about 125 amps as a starting point, but remember the fuse is there to protect the wiring, so plan accordingly.

Thanks again. Yep, I know about the wire and fuse calculators and that the fuse is there to protect the wire. I've done lots of DC wiring in boats, autos, etc. The new stuff for me has to do with the lifepo4 BMS as I've not built batteries before and also never had solar. My plan is to have 16 cells for two 24v battery banks of 8 (280AH) in parallel. I'm struggling a bit on the BMS selection to make sure I get that right.

And I'm also really investigating the source I want to use for the cells. I want new grade A prismatic cells and don't want to get burned with having the distributer deliver something that is not what was advertised since there doesn't seem to be much recourse based on some of the reviews I've seen on DIY Solar Forum so far.

[Ynot4me2]

Thanks again. Yep, I know about the wire and fuse calculators and that the fuse is there to protect the wire. I've done lots of DC wiring in boats, autos, etc. The new stuff for me has to do with the lifepo4 BMS as I've not built batteries before and also never had solar. My plan is to have 16 cells for two 24v battery banks of 8 (280AH) in parallel. I'm struggling a bit on the BMS selection to make sure I get that right.

And I'm also really investigating the source I want to use for the cells. I want new grade A prismatic cells and don't want to get burned with having the distributer deliver something that is not what was advertised since there doesn't seem to be much recourse based on some of the reviews I've seen on DIY Solar Forum so far.

I bought my cells from Docan Power as recommended by the members on diysolarforum, [email protected]. JBD (same bms that I got as recommended on that forum) also has a 24v 8s 100a bms.

[A.Texas.Yankee]

Thanks again. Yep, I know about the wire and fuse calculators and that the fuse is there to protect the wire. I've done lots of DC wiring in boats, autos, etc. The new stuff for me has to do with the lifepo4 BMS as I've not built batteries before and also never had solar. My plan is to have 16 cells for two 24v battery banks of 8 (280AH) in parallel. I'm struggling a bit on the BMS selection to make sure I get that right.

And I'm also really investigating the source I want to use for the cells. I want new grade A prismatic cells and don't want to get burned with having the distributer deliver something that is not what was advertised since there doesn't seem to be much recourse based on some of the reviews I've seen on DIY Solar Forum so far.

Assembling batteries is rather easy, but also very easy to get wrong. I'm a fan of the Daly BMS. They got a lot of bad rep, BUT I've been using 500amp 4s x 12v smart BMS without a problem on a 4s4p stack and it has saved my batteries a few times due to user error. My next set up will be a 2 or 3 paralleled Victron MPII 24v 2 x 120v that I plan to use with either a 8s2p or 8s4p set up (depending on room I have to stuff batteries in on new trailer). I plan to run each series with a Daly Smart BMS that is a 8s x 200amp model with the parallel module.

Tips for buying cells:

Buy a few extra cells. Quality control is pretty good but not perfect and it sucks to wait 3 months for batteries to arrive and have a few defective.

Often suppliers will offer bus bars and are usually pretty good ones. Get double the amount you think you need. Same with nuts. Get welded studs.

There is often a language barrier with suppliers so be very VERY clear on what requests.

There are a few good suppliers and BMS out there. JBD, Overkill, and JK are reputable ones.

[Ynot4me2]

Assembling batteries is rather easy, but also very easy to get wrong. I'm a fan of the Daly BMS. They got a lot of bad rep, BUT I've been using 500amp 4s x 12v smart BMS without a problem on a 4s4p stack and it has saved my batteries a few times due to user error. My next set up will be a 2 or 3 paralleled Victron MPII 24v 2 x 120v that I plan to use with either a 8s2p or 8s4p set up (depending on room I have to stuff batteries in on new trailer). I plan to run each series with a Daly Smart BMS that is a 8s x 200amp model with the parallel module.

Tips for buying cells:

Buy a few extra cells. Quality control is pretty good but not perfect and it sucks to wait 3 months for batteries to arrive and have a few defective.

Often suppliers will offer bus bars and are usually pretty good ones. Get double the amount you think you need. Same with nuts. Get welded studs.

There is often a language barrier with suppliers so be very VERY clear on what requests.

There are a few good suppliers and BMS out there. JBD, Overkill, and JK are reputable ones.

The Daly was my first pick but was out of stock due to Covid. Same with the Docan warehouse in Texas. I got tired of waiting (almost 1 year) and ended up ordering over seas. A little less $ but way longer shipping time. I just took a look at the US warehouse and it now looks like they got some Eve cells in. A little bit more $ though.
I thought (could be wrong) that JBD and Overkill are the same.

[A.Texas.Yankee]

The Daly was my first pick but was out of stock due to Covid. Same with the Docan warehouse in Texas. I got tired of waiting (almost 1 year) and ended up ordering over seas. A little less $ but way longer shipping time. I just took a look at the US warehouse and it now looks like they got some Eve cells in. A little bit more $ though.
I thought (could be wrong) that JBD and Overkill are the same.

JBD & and Overkill are one and the same, Overkill just being a branded version (or other way around, can't remember).