RJ Energy 271 AH LIFEPO4 Lithium Batteries – detailed Top Balancing using the Parallel Step Method procedure

[Danny]

My second Video documenting my project step by step configuring Cheap high quality Lifepo4 cells. I did my best to follow the advice of a trusted expert with several years of experience and who is a marine electrician. Charger settings are detailed. RJ Energy Lifepo4 cells are balanced. The cells were purchased directly from Shenzhen RJ Energy Co.Ltd. MUST READ THIS ARTICLE BEFORE CHARGING https://marinehowto.com/lifepo4-batteries-on-boats/

 

[Raj174]

I read that article just this week and he is spot on. Good advice. Good luck with your cells.

 

[John Frum]

Why 3 voltage steps?
Why not 2 or 1?
Why not let the pack equalise for a few days?

 

[Danny]

Why 3 voltage steps?
Why not 2 or 1?
Why not let the pack equalise for a few days?

This is covered in article I linked to. You need current to move balancing along hooking together and prayer without current does not work according to the expert in unless you prey for many many days....

 

[John Frum]

This is covered in article I linked to. You need current to move balancing along hooking together and prayer without current does not work according to the expert in unless you prey for many many days....

I looked at the article and I would be tempted to do 2 iterations.
1st pass to 3.45 volts and 2nd to 3.6 volts.

 

[Ampster]

1st pass to 3.45 volts and 2nd to 3.6 volts.

I presume that 3.45 is where balancing starts?

 

[John Frum]

I presume that 3.45 is where balancing starts?

I think it depends on the bms but for top balancing there is no bms just cells in parallel.

 

[Ampster]

I think it depends on the bms but for top balancing there is no bms just cells in parallel.

I entirely missed that they were talking about cells in parallel. I must have hung out with bottom balancers too long.

 

[Ampster]

I read the whole thing and it was enlightening and refreshing. I mean refreshing because I forgot some of those concepts and it was good to get a refresher.

I think some of those concepts should be in the Wiki. Coincidentally he bought his Winstons from the same Southern California supplier that I did 8 years ago. Philosophically the author and I use a BMS for monitoring and reporting and we both turn off the balancing circuits He mentioned the auto grade BMSs that I was familiar with from my EV conversion days, Elithion, Emus, and Orion. His paper was not updated with any of the current BMSs that are well reviewed here.

 

[Danny]

Why 3 voltage steps?
Why not 2 or 1?
Why not let the pack equalise for a few days?

I guess I'm challenged enough just doing the projects rather than trying to reinvent what Rod in this article says to do. We can't be experts and get our projects done. We must at some point, rely on the expertise of others who actually have installed and who are using the systems we intend to build. I don't plan to re-balance my pack at all.. ever. My BMS will have balancing turned off. I have now have used Calb 180's and I only charge them to 3.45 per Rods instructions. It works very well. For me, doing a good top balance is very important so I'm not going to experiment and I don't really know any other source I trust more and who does installations on boats. A few extra steps is no big deal for me. Boats burn up and leave you swimming if you are lucky and don't get trapped below decks.

 

[John Frum]

I guess I'm challenged enough just doing the projects rather than trying to reinvent what Rod in this article says to do. We can't be experts and get our projects done. We must at some point, rely on the expertise of others who actually have installed and who are using the systems we intend to build. I don't plan to re-balance my pack at all.. ever. My BMS will have balancing turned off. I have now have used Calb 180's and I only charge them to 3.45 per Rods instructions. It works very well. For me, doing a good top balance is very important so I'm not going to experiment and I don't really know any other source I trust more and who does installations on boats. A few extra steps is no big deal for me. Boats burn up and leave you swimming if you are lucky and don't get trapped below decks.

Faith is not a reliable pathway to truth.

 

[Danny]

I read the whole thing and it was enlightening and refreshing. I mean refreshing because I forgot some of those concepts and it was good to get a refresher.

I think some of those concepts should be in the Wiki. Coincidentally he bought his Winstons from the same Southern California supplier that I did 8 years ago. Philosophically the author and I use a BMS for monitoring and reporting and we both turn off the balancing circuits He mentioned the auto grade BMSs that I was familiar with from my EV conversion days, Elithion, Emus, and Orion. His paper was not updated with any of the current BMSs that are well reviewed here.

I agree. The BMS sections is old and incomplete. You can't get much and you need to learn it elsewhere. The focus is also Boats not EV or off grid. Rod does not trust high amp applications running through MOS FET BMS. Will seems not to trust the MOS FET BMS above 50% their rating. I don't always follow Rods recommendations because of cost but I do use is advise as a sounding board for other's advise. If Will says something that is not consistent with Rod, I'm skeptical. If others differ radically, then I think we should be very cautious. Lifepo4 is the wild west now. You have more experience than me and I value your comment. Thanks for your post.

 

[Thermodynamical]

Danny; fantastic video. The marine power link was a very informative read as well. I'm currently watching your first review video of the batteries. Thanks!

 

[Danny]

I presume that 3.45 is where balancing starts?

My cells in this case were all very near 3.3. Best to have cells near each other before paralleling. Then let them sit and Equalize a bit. I think some of this is in
Rods instructions.

 

[John Frum]

lifepo4 batteries and cells are best charged using constant current/constant voltage.
cc/cv for short.
The constant current part comes first.
During this phase the current flow is controlled by the charger in the only way that it can.
By adjusting the charge voltage relative to the battery voltage.
Since the circuit including the batttery is very low resistance the voltage differential is small.
As the battery voltage rises the charger increases the charge voltage to keep the current constant.
The constant voltage phase begins when the battery can no longer draw the rated constant current.
Now the battery determines the current flow and as the voltages converge the current flow approaches zero.
With that said I don't really see the value of doing multiple steps.
Maybe I am missing something and in that case I would like to know what the benefit of the steps is.

 

[Ampster]

My cells in this case were all very near 3.3. Best to have cells near each other before paralleling. Then let them sit and Equalize a bit. I think some of this is in
Rods instructions.

My comment was made when I thought the cells were in series. I reread the thread and I now understand he was talking about all cells being in parallel. My biggest takaway was that you have to give them voltage to help the current. I liked his philosophy that you don't want to leave them at 3.6 for long. That was the whole point of his step process. I will be paralleling 34 cells (280Ahr) with a 30 Amp power supply so it could be a long time. I dont have to push all 9,000 Amphours into those batteries and I hope that they will arrive at near to 3.32 volts. They did say they capacity tested them. That is when I will be fabricating my connecting straps, ordering studs, nuts and washers. Before that I will run capacity tests on some random cells to get some statistics.

 

[Danny]

lifepo4 batteries and cells are best charged using constant current/constant voltage.
cc/cv for short.
The constant current part comes first.
During this phase the current flow is controlled by the charger in the only way that it can.
By adjusting the charge voltage relative to the battery voltage.
Since the circuit including the batttery is very low resistance the voltage differential small.
As the battery voltage rises the charger increases the charge voltage to keep the current constant.
The constant voltage phase begins when the battery can no longer draw the rated constant current.
Now the battery determines the current flow and as the voltages converge the current flow approaches zero.
With that said I don't really see the value of doing multiple steps.
Maybe I am missing something and in that case I would like to know what the benefit of the steps is.

I’d like to know too. For safety? Rod Collins is an admin on “Lithium Batteries on a boat“ face book group. LBONAB has many advanced members. Maybe ask your questions on the FB group and post answers here? Or let me know your thread. Perhaps you will benefit from reading this group as I have.

 

[John Frum]

I’d like to know too. For safety? Rod Collins is an admin on “Lithium Batteries on a boat“ face book group. LBONAB has many advanced members. Maybe ask your questions on the FB group and post answers here? Or let me know your thread. Perhaps you will benefit from reading this group as I have.

Sorry not on facebook.

 

[Danny]

My comment was made when I thought the cells were in series. I reread the thread and I now understand he was talking about all cells being in parallel. My biggest takaway was that you have to give them voltage to help the current. I liked his philosophy that you don't want to leave them at 3.6 for long. That was the whole point of his step process. I will be paralleling 34 cells (280Ahr) with a 30 Amp power supply so it could be a long time. I dont have to push all 9,000 Amphours into those batteries and I hope that they will arrive at near to 3.32 volts. They did say they capacity tested them. That is when I will be fabricating my connecting straps, ordering studs, nuts and washers. Before that I will run capacity tests on some random cells to get some statistics.

Good point. Stepping involves charging at lower voltage for a longer amount of time and spending a small amount of time at 3.6. Resting at 3.6 like I did was not a good thing I think.

 

[Pacer]

Great video. Paired with that article (which has been referenced many times here), I feel confident to do this balance when my cells arrive.
Also, liked and subscribed to your channel! Thank you for taking the time to demo this for us n00bs!