Low Budget Lifepo4 Experiences anyone?

[Anders]

Originally Posted by more

i think lot of people don't understand EU law. for every bolt, every material in any building, a vehicle must have a Certificate when the inspector asks. you can use a vehicle, building after the inspector approves.

The only EU law for boat standards are that the they comply with RCD when imported unless excempt or sold new in the EU.
Our boat has no requirement to follow on equipment and it has never seen an inspector since there are no requirements for an inspection.

[more]

Originally Posted by Anders

The only EU law for boat standards are that the they comply with RCD when imported unless excempt or sold new in the EU.
Our boat has no requirement to follow on equipment and it has never seen an inspector since there are no requirements for an inspection.

I see an inspector every year for every boat in the fleet.

[Anders]

Originally Posted by more

I see an inspector every year for every boat in the fleet.

But that is a law in your country. It's not an EU law.

[noelex 77]

Originally Posted by more

i have but this is a lug for UPS no DIN
i can crimp cable but I don't connect to the boat.I sell this battery,lug but this is not for use only for show.

The example I suggested was from Cembre who are a well regarded UK manufacturer. Their lugs are good quality and conform to UNI EN 13600 and UL 486A standard according to their website. They have a CE and UL stamp on each lug. They are widely used on European CE certified boats so I am surprised you are finding a problem using these in Croatia, but boatbuilding standards can be a bit stupid and counterproductive at times.

I hope the Croation boatbuilding standards did not approve and certify the circuit breaker that you pictured in post #273.

What brand of lugs would you normally use? Doesn’t this manufacturer produce a 90/6?

[sparrowhawk1]

? The lug shown is for a much heavier cable I don't know the exact spec but it matches the original wiring for my Columbia 11.8. background of the photo is representation of actual size 10 to 12 gauge terminals for comparison along with the quarter. You must be a troll, I'm done.

Originally Posted by more

On picture is Lug for wire range AWG 10-12 6mm2 to 4mm2
ok this is for connecting electric toilet maybe so thin for 1 toilet What with rest of ship. cable lug DIN 46235 possible order cable 35mm2 AWG 2 cable but also this is to small because Cable dimension calculate must be On boat all consumption on max voltage drop max 10%
bow thruster, anchor windlasses

[Franziska]

Hi, we finally decided to order the equipment earlier than planned, most of it is on its way :-)

One more question, especially for
@newhaul

Does it make sense to have the 3 Epever 40 Amp outputs going into a common bus bar (one+, one-) and than feed this into the 3 battery blocks.

Each of our battery blocks has an BMS and auto load balancer.

Than we could have another set of bus bars on the output side of the batteries.

One - for a common negative and one + for the circuits coming from the switchboards.

Is that a good idea?
Guess it would ensure all batteries are used evenly.

[newhaul]

Originally Posted by Franziska

Hi, we finally decided to order the equipment earlier than planned, most of it is on its way :-)

One more question, especially for
@newhaul

Does it make sense to have the 3 Epever 40 Amp outputs going into a common bus bar (one+, one-) and than feed this into the 3 battery blocks.

Each of our battery blocks has an BMS and auto load balancer.

Than we could have another set of bus bars on the output side of the batteries.

One - for a common negative and one + for the circuits coming from the switchboards.

Is that a good idea?
Guess it would ensure all batteries are used evenly.

Yes that would be the correct way to do it

[CaptainRivet]

Originally Posted by newhaul

Yes that would be the correct way to do it

Not really correct...
Use One BMS for the whole house battery, if you use more then one BMS they will interfere with each other especially under high loads like big inverter and cause the cells to deplete differently.
2nd more then one BMS requires the wrong battery config. You make packs of 2 or 3 cells in parallel and then series connect them. Serveral BMS means you make packs of 4 in series and parallel the 4 series packs. 1st and last cell of each 4 cell series pack will see much higher loads, age faster and differ much more. Balancer cannot work properly like this too as it lS not recognizing rhe whole battery, just the one 4 series pack. 3rd more connections, more resistance, more material, more to fail, more costs... 4th the cells need to be compressed and because they have the plus pole to the chassis you wanna add an isolator between 2 cells in series but you don't need one between parallel cells. Again more material, more weight and not an even compression between all cell, just between 4 in series.

If you parallel 3 cells they equalize each other naturally and share the load without any electronic involved. The one balancer then just balances the 4 packs in series and recognizes the whole house bank in total and can work properly.

Yes drop in have it like you planed and it works but it has a lot of disadvantages,the 4 described above are the 4 major ones. You can make it better with raw cells.

[newhaul]

Originally Posted by CaptainRivet

Not really correct...
Use One BMS for the whole house battery, if you use more then one BMS they will interfere with each other especially under high loads like big inverter and cause the cells to deplete differently.
2nd more then one BMS requires the wrong battery config. You make packs of 2 or 3 cells in parallel and then series connect them. Serveral BMS means you make packs of 4 in series and parallel the 4 series packs. 1st and last cell of each 4 cell series pack will see much higher loads, age faster and differ much more. Balancer cannot work properly like this too as it lS not recognizing rhe whole battery, just the one 4 series pack. 3rd more connections, more resistance, more material, more to fail, more costs... 4th the cells need to be compressed and because they have the plus pole to the chassis you wanna add an isolator between 2 cells in series but you don't need one between parallel cells. Again more material, more weight and not an even compression between all cell, just between 4 in series.

If you parallel 3 cells they equalize each other naturally and share the load without any electronic involved. The one balancer then just balances the 4 packs in series and recognizes the whole house bank in total and can work properly.

Yes drop in have it like you planed and it works but it has a lot of disadvantages,the 4 described above are the 4 major ones. You can make it better with raw cells.

The way i told them is correct is absolutely correct for the way they have decided to configure their bank . Its not ideal and not how i would do it but it is how they have decided to do the cobfiguration .

[more]

Originally Posted by Franziska

Each of our battery blocks has an BMS and auto load balancer.

Rimac car have 120 kWh battery with thousand cell inside and only one BMS
Supercharger 240 kw and only one BMS.
Also tesla car huge bunch cell and one BMS,also supercharge.
Don't buy 3 BMS you don't need this.

[CaptainRivet]

Originally Posted by more

Rimac car have 120 kWh battery with thousand cell inside and only one BMS
Supercharger 240 kw and only one BMS.
Also tesla car huge bunch cell and one BMS,also supercharge.
Don't buy 3 BMS you don't need this.

Right, its even contraproductive as the 3 BMS interfere with each other and cause imbalances the bigger rhe load the bigger the interference and imbalance gets. If you want redundancy use one BMS and put a 2nd in parallel separated by switches, so you can use one or the other... Better just have a 2nd packed in a vacuum bag with you in case rhe BMS fails.

But as said before with the expected load and 840AH if they are correctly top balanced before the build and put in 3p4s config you don't necessarily need a BMS if you have a battery monitor like Victron BMV712 which can switch a relay in case of over and undervoltage situation. If you are smart its configured and installed like this anyhow as last line of defense in case BMS fails. If you add a active balancer even better... So if BMS dies not the end of the world/enough time to order a new one and run it without BMS.

[Franziska]

Thanks to all of you.
I'm starting to get thoroughly confused after all :-) even though I thought I had a final understanding before.

What we have now on its way, but have not put together yet, is as follows below.
We will not change this equipment anymore to other brands and to not want to discuss advantages of other brands anymore.
This is what we have.

Still we appreciate very very much complete and easy to follow instructions of how to assemble this best to achieve good longevity.

We can leave components away if consensus is, that is better for longevity.

Regarding power draw, no really big inverters (max 1500w).
Complete system after MPPT will be 12V.

Here are the components we have bought or have already existing:

(1x) Rutland 1200 Windgen

(3x) 400Wp Solar panels
(had to reduce panels slightly due to space & cost)

(1x) Rutland 1200 wind controller

(3x) Epever 4210AN 40A MPPT solar controller.
We will adjust/set the initial parameters from the PC interface and will mount them so that we can use the built in displays and buttons for daily tasks.
We will not mount additional Bluetooth or displays.

(3x) Sets of four LiFePo4 cells.
280Ah@3.2V per cell. So a total of 12 3.2Vcells.

(3x) Auto load balancer
https://www.aliexpress.com/snapshot/0.html?orderId=8131010853148282&productId=40011712 01818&edm_click_module=order_detail&tracelog=rowan &rowan_id1=sellerSendAllGoodsToBuyerV2_1_de_DE_202 1-05-02&rowan_msg_id=8282813101085313$3bf2d3a1cdcc4a5b8 25bbb35329217b0&ck=in_edm_other

(3x) BMS Model 4S LiFePo4 120A
https://www.lithiumbatterypcb.com/pr...ter-power-ups/

(1x) Battery Capacity Tester Coulometer DC8-80V 50A 100A 350A Battery Tester Monitor Indicator Ammeter Voltmeter for Pb Li-Lon Lifepo

No alternators as we have only outboards.

We also have a 220V/110V 40A charger which we plan to connect with a switch, so that charging is either wind&solar OR charger only.
We may replace this charger if it is not fit for LiFePo4.
This can also be driven by the 2kw genset which we still have, but may get rid off eventually.

As described above the plan was:

A)
Each solar panel connected to dedicated controller.
Windgen connected to wind controller.

B)
Output of all controllers to a common positive and a common negative bus bar.

C)
Mainswitch, to switch between wind&solar or mains charger.

D)
(And from here on we are open to clear instructions!)
Options to connect cells, auto load balancers and BMS.
The batteries will be compressed and I put a dry piece of non resin impregnated fiberglass mat between the cells as additional insulator (neglectable weight.)
The batteries will go into a box with a heating element which kicks in below 6degree centigrade.

Option one:
The initial plan, create three 12V 240Ah batteries each with its own BMS and cell auto load balancer.

Option two:
Create one big 12V 840Ah battery. With one BMS and one cell auto load balancer.
I am uncertain how we can wire this up with our existing BMS and load balancer.
In this case we have 2 balancers and BMS as spare or for sale.

E)
At the business end of the batteries:
One common negative bus bar to which all negative user terminals attach.
One common positive bus bar to which the breaker panels are attached.

F)
Attach the battery capacity tester to the common busbars at the business side (=output side) of the battery.

This is where we stand now.

I guess the main question is what we do from point D) onward?
The aim is to have a system which requires a minimum of adjustment and maintenance in daily use.
This system shall not become a new hobby or daily chore.

I really appreciate if someone can for a last time comment on this to clear things up.

[wholybee]

Either approach is fine. People have opinions, but that doesn't make one way better than another way. Consider that anyone buying 3 battleborns and putting them in parallel is literally doing the exact thing you are planning. 4s3p with 3 BMS offers some redundancy if a BMS fails, and will support higher current-necessary if you will be cooking electric. 3p4s with one BMS (assuming you use the same BMS you choose) will not handle as high currents, but will stay in balance better. Staying in perfect balance shouldn't be an issue, as you have added active balancers. I think the active balancers are probably unnecessary, but won't hurt. Use 'em if you got 'em.

If you have put a alot of time and planning into your build, I would not change it at this point. Understanding, that if you did run into an issue you could reconfigure to a 3p4s without buying anything much else. (you would need more bus bars, and to build a new frame to hold all the cells) I don't anticipate any issues.

I choose 3p4s for my build, because it takes less space, and I could fit a higher capacity bank. I otherwise would have preferred 4s3p as you are planning.

If you have not done so already, download the Overkill Solar manual from their website. It is very well written, and appears it might be the same BMS you bought, just branded differently.

[CaptainRivet]

Originally Posted by Franziska

Thanks to all of you.
I'm starting to get thoroughly confused after all :-) even though I thought I had a final understanding before.

What we have now on its way, but have not put together yet, is as follows below.
We will not change this equipment anymore to other brands and to not want to discuss advantages of other brands anymore.
This is what we have.

Still we appreciate very very much complete and easy to follow instructions of how to assemble this best to achieve good longevity.

We can leave components away if consensus is, that is better for longevity.

Regarding power draw, no really big inverters (max 1500w).
Complete system after MPPT will be 12V.

Here are the components we have bought or have already existing:

(1x) Rutland 1200 Windgen

(3x) 400Wp Solar panels
(had to reduce panels slightly due to space & cost)

(1x) Rutland 1200 wind controller

(3x) Epever 4210AN 40A MPPT solar controller.
We will adjust/set the initial parameters from the PC interface and will mount them so that we can use the built in displays and buttons for daily tasks.
We will not mount additional Bluetooth or displays.

(3x) Sets of four LiFePo4 cells.
280Ah@3.2V per cell. So a total of 12 3.2Vcells.

(3x) Auto load balancer
https://www.aliexpress.com/snapshot/0.html?orderId=8131010853148282&productId=40011712 01818&edm_click_module=order_detail&tracelog=rowan &rowan_id1=sellerSendAllGoodsToBuyerV2_1_de_DE_202 1-05-02&rowan_msg_id=8282813101085313$3bf2d3a1cdcc4a5b8 25bbb35329217b0&ck=in_edm_other

(3x) BMS Model 4S LiFePo4 120A
https://www.lithiumbatterypcb.com/pr...ter-power-ups/

(1x) Battery Capacity Tester Coulometer DC8-80V 50A 100A 350A Battery Tester Monitor Indicator Ammeter Voltmeter for Pb Li-Lon Lifepo

No alternators as we have only outboards.

We also have a 220V/110V 40A charger which we plan to connect with a switch, so that charging is either wind&solar OR charger only.
We may replace this charger if it is not fit for LiFePo4.
This can also be driven by the 2kw genset which we still have, but may get rid off eventually.

As described above the plan was:

A)
Each solar panel connected to dedicated controller.
Windgen connected to wind controller.

B)
Output of all controllers to a common positive and a common negative bus bar.

C)
Mainswitch, to switch between wind&solar or mains charger.

D)
(And from here on we are open to clear instructions!)
Options to connect cells, auto load balancers and BMS.
The batteries will be compressed and I put a dry piece of non resin impregnated fiberglass mat between the cells as additional insulator (neglectable weight.)
The batteries will go into a box with a heating element which kicks in below 6degree centigrade.

Option one:
The initial plan, create three 12V 240Ah batteries each with its own BMS and cell auto load balancer.

Option two:
Create one big 12V 840Ah battery. With one BMS and one cell auto load balancer.
I am uncertain how we can wire this up with our existing BMS and load balancer.
In this case we have 2 balancers and BMS as spare or for sale.

E)
At the business end of the batteries:
One common negative bus bar to which all negative user terminals attach.
One common positive bus bar to which the breaker panels are attached.

F)
Attach the battery capacity tester to the common busbars at the business side (=output side) of the battery.

This is where we stand now.

I guess the main question is what we do from point D) onward?
The aim is to have a system which requires a minimum of adjustment and maintenance in daily use.
This system shall not become a new hobby or daily chore.

I really appreciate if someone can for a last time comment on this to clear things up.

Hi Franziska,
Just short as I am busy. I just bought 24 cells 272AH Lishen and will use 12/840AH for myself and 840AH for a buddy boat installing them till end June.
It’s a tricky topic, you have outboards so one problem less to deal with
840AH LifePo4 is a beast and short circuit is more then 8000A, are your fuses rated for that so a lightbow of 8000A is not bridging them suggest Siemens LH3 fuses for the high current stuff like inverter and so called 500A Trennmesser as main fuse, they have 20000A lightbow Rating....from professional high current installation and cheaper then the marine branded stuff.

This is a video how you connect them in 2p4S config, for 3p just add a 3rd cell to the 2 and use a washer underneath so the Busbars are even before you tie them down

https://www.youtube.com/watch?v=OiOwHEYg_34

Also good info for Top balancing the cells before you build your house bank.

Sorry to say but if you want longevity and safe, you chosen the wrong BMS...it’s just crap and a big and 1 or 3 won't handle your loads . Rated for 120A or 200A, well I won‘t „trust“ them more then 50A and trust 0 just from cable size and cheap mosfets...
No idea why you chosen this one. A good,tested and reliable budget BMS are Daly.At ebayKleinanzeigen you can find a guy selling them from German stock, I would get the 250A one, it’s 250Euro. Running electronics on its limit shortens life and the 250A has enough room/safety margin.
Do you have a battery monitor which can initiate to cut loads? If not I highly recommended a Victron BMV712, yes it’s not budget but worth every penny. Besides control and monitor the bank, You can configure it and use its warning and switched output to disconnect the bank at hi and low voltage points as last line of defense in case BMS screws up. This is even more important then the BMS. With your low loads you could even run the bank without BMS if properly top balanced in 3p4s config.

Nearly forgot:

Ruthland: did you get the modified lithium controller, if not you need this one as the standard one will blow up when disconnected under load.

Christian

[CaptainRivet]

Originally Posted by wholybee

Either approach is fine. People have opinions, but that doesn't make one way better than another way. Consider that anyone buying 3 battleborns and putting them in parallel is literally doing the exact thing you are planning. 4s3p with 3 BMS offers some redundancy if a BMS fails, and will support higher current-necessary if you will be cooking electric. 3p4s with one BMS (assuming you use the same BMS you choose) will not handle as high currents, but will stay in balance better. Staying in perfect balance shouldn't be an issue, as you have added active balancers. I think the active balancers are probably unnecessary, but won't hurt. Use 'em if you got 'em.

If you have put a alot of time and planning into your build, I would not change it at this point. Understanding, that if you did run into an issue you could reconfigure to a 3p4s without buying anything much else. (you would need more bus bars, and to build a new frame to hold all the cells) I don't anticipate any issues.

I choose 3p4s for my build, because it takes less space, and I could fit a higher capacity bank. I otherwise would have preferred 4s3p as you are planning.

If you have not done so already, download the Overkill Solar manual from their website. It is very well written, and appears it might be the same BMS you bought, just branded differently.

I tested this config with 8x 272AH Lishen cells configured in 4 series packs and 2 Cheap BMS, the higher the load the more the 2 BMS interfered and cell voltages drifted apart. Also during charge and even drifted further apart then with no BMS and just a Victron BMV712 to cut for LV/ HV cutoff connected. Also you couldn‘t charge it to 100%Soc as 2 cells were too high and BMS cut charging, guess which cell = yes the last cell which sees the most load.Cells were properly top balanced before. There is also a video on YouTube where a guy tested his 8 cells 280AH eve and got exactly the problems described here, he just didn‘t now the origin of his issues...
Maybe I find it and will post.

I can show you dozen of similar looking BMS on Alixxxx but they have nothing in common with the overkill one, so does this one

A reliable, tested budget BMS are Daly which you can get up to 500A.
Will Prose tested the 272AH Lishen with a 250A Daly BMS and this pulled even 292A without an issue when he run it with a 3500W inverter and bat was near cutoff, so voltage down Amps raised.
If you are not an expert and especially if you want to do a budget build, I suggest get proven combos of equipment and don‘t play the genipig. Crap doesn‘t get better when you parallel it...
840AH lifepo4 is a beast, see posting above...