LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[OceanPlanet]

Originally Posted by offpist

Testing out the Balmar AT-200 together with an Balmar 60-150-SR-IG on an Yanmar 4JH4E. Gives me 350A charging power for my 1000AH Lifepo4 setup.

Controlled by two Mastervolt Alpha Pro MB regulators.

As its 10 groove Serpentine on both alternators, i am not too worried about bearings wear on the engine. But maybe I should be?

For now I have limited at 50% output on the regulators, still giving me plenty of power and the alternators are running very cool this way.

If I want full power I can deactivate "small engine" mode.

Balmar is P+ regulated, and Mastervolt is N- regulated, but that was easy to fix.

Very nice! For many of these Yanmar engines we have been able to fit modified American Power 42i large-case J180's into the small case position, using custom pulley/belt kits. Not always...but when we can it is very slick for charging Li banks. Here is a pic of a recent custom 24V x 160A AP 42i on a Yanmar Y3M30. This was for a custom 53ft Bieker cat by Gold Coast yachts, so with two engines they can charge at around 250A @ 27V.

For 12V boats we have done similar, for a solid 400A @ 14V (two engines).

[SYEnigma]

Originally Posted by OceanPlanet

We used to really believe in CALB, having sold them for many years in the Genasun GLi systems. However have been having issues lately, especially with the new CA cells. Even with supposedly identical specs, there have been differences in coloumbic efficiencies, making them difficult to balance in high-current charging applications. We switching to something else where our mfg has more control of the supply chain to ensure better QC.

Very disappointed to hear that the Newer CALB CA cells are proving difficult to Balance at high charge currents. I was about to invest in the CALB CA 100FI cells. What brand cells would you recommend, or what brand are you currently using to get the more consistent QC. Thanks in advance..

[Singleprop]

Oceanplanet:

What cells are you having trouble with, the CAxxxFI's or the new CAMxxxFI's?

[OceanPlanet]

Originally Posted by SYEnigma

Very disappointed to hear that the Newer CALB CA cells are proving difficult to Balance at high charge currents. I was about to invest in the CALB CA 100FI cells. What brand cells would you recommend, or what brand are you currently using to get the more consistent QC. Thanks in advance..

We are now working with Lithionics, and working together have developed a new modular plug & play dual-channel (dual-bus) BMS to our specifications learned from many years with Genasun. We are adamant about using dual-channel for house banks and also about the details of the HVC/LVC settings on both the charge and discharge channels.

The cells used by Lithionics are not available outside of complete packs/systems (that I know of). They have better control of their supply chain (and won't divulge the exact details). However I do know that their cells are the only type available in the US with the ION-EXT cell separator technology by Mitsui that shuts down the cells if they overheat.

To address Singleprop's question (CA vs CAM) I'll have to ask Genasun. As an over $1M client with CALB, Genasun is very disheartened with the lack of responsiveness from CALB to address or even explain the changes in QC. So much so that Genasun is backing out of the Li battery game for marine applications. We have known this for a while so that's why we have been working for some time in the background with Lithionics to develop our new OPE-Li3 BMS

I know this thread is more for the DIY crowd, and certainly with careful research, electrical experience, and diligent maintenance a DIY Li system can work. Maine Sail is a perfect example. However for our market of builders, installers, and users who don't want to worry, we need to provide a system like the OPE-Li3 configuration.

The functionality of Genasun has been very good, and I owe most of what I know from working with them over the years. However Lithionics has the resources to take things to the next level: dependable cell supply chain, watertight cases, more robust and watertight cell loop wire, more reserve capacity after first LVC, UN-DOT approval for shipping (no more hazmat drums), and the responsiveness to quickly create our new BMS to our specs.

[Singleprop]

You mention this happens during high current charging. What would that be: 1C, 2C or 3C

- in that case it might not be so relevant for the average user who generally charges at around 0.3-0.5C.

[SYEnigma]

OceanPlanet:

Thank you for your prompt and detailed reply, I have closely followed your WebSite for some time and have seen the recent release of the new Lithionics OPE-Li3 BMS. They look the way forward in LiFePO4. I am a DIY out of financial necessity and also due to the fact I sail in very remote places.. I am retiring a set of 10 year old and excellent Sonnenshine Gel Battery's and am like many others on this forum looking to increase amp hours without the extra added space and weight, and most importantly looking to maximise my energy budget with a reliable and long lasting system.. At the present time LiPO is the most mature of all the newer technologies and is becoming more attainable for the DIY crowd who is willing to spend the time, effort and research required to set up a safe system. Thanks again for your information and my research continues...

[OceanPlanet]

Originally Posted by Singleprop

You mention this happens during high current charging. What would that be: 1C, 2C or 3C

- in that case it might not be so relevant for the average user who generally charges at around 0.3-0.5C.

Good question. Note that the max charge we've been recommending for the past few years is 1.2C or so.

At what lower rate does the balancing keep up? I don't know, other that Genasun has been making them work out for some polar/solar applications with low charge/discharge rates. We aren't involved with those projects so don't know the details, other than the fact that Genasun tells us they don't trust the cells for marine any more.

[OceanSeaSpray]

Voltage-based balancing BMS solutions don't work and will never work at high currents. As soon as there are differences in the internal resistance of the cells, the voltage information they use to make balancing decisions gets skewed by the current and they start throwing the pack out instead of balancing it.

Real-time "active" balancing - to "maximise capacity" as some vendors put it - is nonsensical. You would need to be able to transfer the full charge/discharge current from cell-to-cell at times to be able to keep up, which is never going to happen and would cost a fortune.

When you look inside a Mastervolt pack, you can see that it is not capable of transferring more than about 20A probably from cell to cell (30A fuse), and this already requires large switch-mode transformers. This type of design is possible, but it is complicated, costly and makes no sense.

Short of being incredibly lucky when buying the cells and operating them quite conservatively, balancing becomes necessary after "a while" to keep the system working properly. However, "no balancing" can be a longer lasting/better performing option than trying to balance with a junk-grade solution like cell boards and the like.

[bill good]

Can say from trying to use the "car" type of alternator set up on small marine engine & the loading from life batteries at the low end of the RPM range has lead me to go with a system that inhibits the load on the charging until the RPM is up to a level where the HP going to the battery is not loading engine or alternator. (picked 2000 RPM). Belts were a problem at the lower RPM but not at the higher RPM. The Yanmar 1GMS on my boat have "bogged down" on start up with 40A/H battery & prevented getting the RPM up when put into gear. Nearly 4yrs with life start batteries & very pleased the lead is out.

[OceanPlanet]

Originally Posted by OceanSeaSpray

Voltage-based balancing BMS solutions don't work and will never work at high currents. As soon as there are differences in the internal resistance of the cells, the voltage information they use to make balancing decisions gets skewed by the current and they start throwing the pack out instead of balancing it.

Real-time "active" balancing - to "maximise capacity" as some vendors put it - is nonsensical. You would need to be able to transfer the full charge/discharge current from cell-to-cell at times to be able to keep up, which is never going to happen and would cost a fortune.

When you look inside a Mastervolt pack, you can see that it is not capable of transferring more than about 20A probably from cell to cell (30A fuse), and this already requires large switch-mode transformers. This type of design is possible, but it is complicated, costly and makes no sense.

Short of being incredibly lucky when buying the cells and operating them quite conservatively, balancing becomes necessary after "a while" to keep the system working properly. However, "no balancing" can be a longer lasting/better performing option than trying to balance with a junk-grade solution like cell boards and the like.

At least a couple of the newer BMS's we know of do either some sort of resistance measurements at the cell level, and/or somehow track/log cell balancing requirements so that the balancing can get started "ahead" of the voltage curve. I don't know enough about it to describe in detail, and of course they don't want to tell me too much either....

[OceanSeaSpray]

Originally Posted by OceanPlanet

At least a couple of the newer BMS's we know of do either some sort of resistance measurements at the cell level, and/or somehow track/log cell balancing requirements so that the balancing can get started "ahead" of the voltage curve. I don't know enough about it to describe in detail, and of course they don't want to tell me too much either....

That's right, you can't claim to balance in real-time when things are going west, so you have to do it pro-actively based on recent data.
The issue is that - short of having access to and using cell current information - you can only try to fudge things.
Also - if you claim balancing - you need to be able to make very fine and precise voltage measurements, with a great degree of consistency from cell-to-cell. The gear we commonly see around is not up to it.

What I could find when I wanted a BMS was so inadequate, undesirable and risky that I decided to develop my own. A BMS is not just protecting a battery, but also a very large-value asset. After that I built some more of them, because they are safe and resilient and don't burn any power. Those don't balance and no cell differences developed after one year. The issue I see with going further with it is price competition from junk-grade solutions that pretend to do more or less the same.
I am now working on second generation hardware based on what I have observed and then we will see. The new design will be able to correct for balance issues, but also manage the bank in general with much more functionality.

[stefano_ita]

i've read here and there this thread throught the years...

how many average cycles do we get from winston lifeYpo4? average DOD?

i have a big question: how to use a 12 V or 24 V lifeYpo4 battery pack (controlled and keep balanced by BMS) as main an only battery pack, recharging them with a second alternator (if not even a 3rd, look at this

https://www.youtube.com/watch?v=kaIkHWq-mXY

)

is it possible to buy some voltage regulator for lifepo to replace the original PB battery voltage regulator (from the original alternator)?

with PB battery i found all what i need in 2 minutes..but..i want something that last lot of thousand cycle (i calculated average 30% dod)...and sealed and safe..

thanks all

[Hyprdrv]

Has anyone here used the ORION BMS system? Any comments?


Steve in Solomons MD

[georgec]

Originally Posted by Singleprop

You mention this happens during high current charging. What would that be: 1C, 2C or 3C

- in that case it might not be so relevant for the average user who generally charges at around 0.3-0.5C.

My 12v bank of 8 CALB CA400FI have a cell difference from the high cell to the low cell of between .008v to .012v. I installed the bank in May and this variation has been consistent all season. My max charge capacity is 150 amps which is about .2C.

[ColdEH]

My 600 ah house bank of Sinopoly's (8x300ah) after one year installed , balance at .003 and .007 volts in around a one third state of charge . I charge at 220 amps .

Regards


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