How to wire BMS that Will P was so excited about!

[TEP]

Hi Folks, my first Post

My project is for a vintage GMC Motorhome of the 70's era. The house bank of (LifeP04) Were purchased from Lion Energy and were offered on EBAY for $400each.
(https://www.ebay.com/itm/Interlocki...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649)



Two batteries were shipped and packed in a very robust fashion. I was impressed. The buss bars were all removed and packed separately. That said, I'm having a difficult time determining the hookup of the BMS that WiLL P demonstrated in one of his u-tube shoutouts. (Smart Lifepo4 li-ion Lipo LTO Battery Protection Board BMS 48V 72V Bluetooth 20S) No documentation arrived with the BMS. The only thing that I'm able to read for documentation was listed at the bottom of the E BAY listing.

So I have 16 Cells that I want to configure and achieve two 1200 W batteries While using the BMS that WILL P was excited about. Any insight?

 

[SCClockDr]

I understand you wish to use one BMS. That would dictate a 2p8s arrangement for one 24 volt battery or with two BMS's an 8s2p arrangement is possible.
In either case you will have a 4.8 KWh capacity.

 

[Supervstech]

Hi Folks, my first Post

My project is for a vintage GMC Motorhome of the 70's era. The house bank of (LifeP04) Were purchased from Lion Energy and were offered on EBAY for $400each.
(https://www.ebay.com/itm/Interlocking-LiFePO4-3-2v-50Ah-Lithium-Iron-Li-Ion-Batteries-Harness-8-cells/362829435235?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649)


View attachment 3862
Two batteries were shipped and packed in a very robust fashion. I was impressed. The buss bars were all removed and packed separately. That said, I'm having a difficult time determining the hookup of the BMS that WiLL P demonstrated in one of his u-tube shoutouts. (Smart Lifepo4 li-ion Lipo LTO Battery Protection Board BMS 48V 72V Bluetooth 20S) No documentation arrived with the BMS. The only thing that I'm able to read for documentation was listed at the bottom of the E BAY listing.

So I have 16 Cells that I want to configure and achieve two 1200 W batteries While using the BMS that WILL P was excited about. Any insight?

Your picture shows 2p4s, arrangement on your cells, and a 5 wire BMS loom... so, 12v... right?

 

[Supervstech]

Hi Folks, my first Post

My project is for a vintage GMC Motorhome of the 70's era. The house bank of (LifeP04) Were purchased from Lion Energy and were offered on EBAY for $400each.
(https://www.ebay.com/itm/Interlocking-LiFePO4-3-2v-50Ah-Lithium-Iron-Li-Ion-Batteries-Harness-8-cells/362829435235?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649)


View attachment 3862
Two batteries were shipped and packed in a very robust fashion. I was impressed. The buss bars were all removed and packed separately. That said, I'm having a difficult time determining the hookup of the BMS that WiLL P demonstrated in one of his u-tube shoutouts. (Smart Lifepo4 li-ion Lipo LTO Battery Protection Board BMS 48V 72V Bluetooth 20S) No documentation arrived with the BMS. The only thing that I'm able to read for documentation was listed at the bottom of the E BAY listing.

So I have 16 Cells that I want to configure and achieve two 1200 W batteries While using the BMS that WILL P was excited about. Any insight?

Oh, and I wanna see pics of the Motorhome! I loved that style vehicle. I like the diesel conversions done on the puller!

 

[TEP]

Your picture shows 2p4s, arrangement on your cells, and a 5 wire BMS loom... so, 12v... right?

Because they were shipped with the buss bars removed I can only report out is "what you see is what I see"in the Ebay image. Ive done some more searching on WILL P's u tube Postings and arranged the battery packs in parallel pairs. See image attached. That said, how can the BMS (Smart Lifepo4 li-ion Lipo LTO Battery Protection Board BMS 48V 72V Bluetooth 20S) be used to monitor both batteries? If both of the batteries were then put in series would my BMS then be functional?

 

[Deleted member 783]

Oh, and I wanna see pics of the Motorhome! I loved that style vehicle. I like the diesel conversions done on the puller!

Those dual rear axle land yachts are the best! Many memories.

 

[TEP]

Well i just had another brain F--T.

If both batteriess were connected in series that means 8 cells, yes? From the Ebay/BMS instructions I selected the cartoon that appears to be the most appropriate called the "8 string" Can any one validate my choice?

 

[Steve_S]

I just want to clarify here. You want to use 1, 16S BMS to manage 2 battery packs ? That won't work. You will need 2, 8S BMS's, one for each 12V pack. The AliExpress item you listed comes from here: https://www.lithiumbatterypcb.com/p...battery-pcb-board/smart-bms-of-power-battery/ there IS MORE INFO AND OPTIONS ON THAT SITE... but the devil is in the details, so be sure you are looking at the right LFP solution for your setup, note the amperage ratings particularly.

 

[TEP]

So I'm still not understanding. As shown before I have two 4 cell batteries and if I connect them in series I will have an 8 cell package that I want to monitor, yes? The "8 Strings" wiring diagram seems to be appropriate, if not what have I missed?

It's the day before Christmas......so don't struggle with an immediate response.

 

[SCClockDr]

1. Clear all the bus bars off the cells.
2. Arrange the cells in an alternating line +>->+>-
3. Now connect all the ->+ pairs.
4. Leave the +>- pairs alone. (No bus bar)
5. You should read >24v from the top left + to the bottom right -.

You now have one 24 volt battery. Follow Will's guidance for the BMS harness connections.

 

[TEP]

So, Okay George, I think you're telling me that I screwed up buying the Single BMS With blue tooth and many other Features to monitor a 12V system?

 

[Steve_S]

1 string = # of cells to that are combined to make a specific pack which outputs X volts & X amps.
1 string of 4, 3.2 Volt cells = 12.8V pack.
1 string of 8, 3.2 Volt cells = 25.6V pack
2 strings of 8 (16 cells total) 3.2V tied together parallel = 25.6V

Example of a 24V 16 cell 8s2p (long format) setup.

 

[Steve_S]

You now have one 24 volt battery. Follow Will's guidance for the BMS harness connections.

Link Please, I have not seen any of Will's "Guidance on BMS wiring" as such... I even put in a suggestion to do something like that along with a few other items to simplify everyone's lives. Link to that thread here: https://diysolarforum.com/threads/suggestion-forum-diy-vids-or-tuts.2741/

 

[Supervstech]

So, Okay George, I think you're telling me that I screwed up buying the Single BMS With blue tooth and many other Features to monitor a 12V system?

Correct.
If you want 12v output from your bank, you need to have 4 separate BMS installed on each 4 cell bank if you want to individually monitor your cells.

 

[Supervstech]

The number of cells a bms will monitor is based on the voltage of the pack.
4s = 14ish volts
8s =28ish volts
And so on...

 

[MisterSandals]

Are you guys even sure what voltage the OP trying to achieve?

The link to the BMS that the OP implies he has purchased, shows 48v. There are quite a few questions about what voltage and quite a few diagrams for 12v and 24v. The OP has 2P4S pictured (12v) yet he has 16 cells.

And yes, pics of the GMC please!

https://www.reddit.com/r/funny/comments/a7ibkz

 

[TEP]

So here are images of my GMC project called the "Pearl Princess" As purchased :

As gutted, engine rebuilt, House wiring upgraded, repainted and awaiting further LifeP04 battery set, EFI and rebuilt frt and rear suspension. Slo but fulfilling for me:

 

[TEP]

So as to be as clear as possible I am trying to use the 16 (3.4V) batteries and configure them to power 12V items in this small Class A coach. I have already purchased the BMS previously discussed and have the LCD, temp sensors and Bluetooth ready device. How can I rescue my purchases with out buying a another BMS?

 

[TEP]

I don't want to monitor each of the 16 Cells. The way I have them currently configured in the sketch I have 8 cells to monitor, yes ?

 

[John Frum]

So as to be as clear as possible I am trying to use the 16 (3.4V) batteries and configure them to power 12V items in this small Class A coach.

What chemistry has a nominal voltage of 3.4v?