LiFePo4 battery setup questions

[boom23]

I am looking into a 12V 700Ahr LiFePo4 battery house bank. I would like to use four 700Ahr Winston batteries (sold by Balqon Corp), and HousePower BMS system.

I will need 4 MiniBMS cell boards (3.8V, size “E”) and one HousePower BMS board for 12V.

I will be charging the battery bank using a Victron MultiPlus, Victron MPPT (solar), two Yanmar 80A alternators, and Watt & Sea Hydrogenerator. How do I deal with multiple charging sources?

According to the limited documentation, the MultiPlus, MPPT and Hydrogenerator are Lithium compatible and in the worse case, the BMS can stop charging input to the batteries. Anything I should know?

How about the alternators? How do I deal with them?

My alternators are the stock HITACHI LR180-03C ones with built-in regulators. According to their one page documentation, they provide 80A (not sure about the RPM curve) at 13.8V.


Any input is appreciated.

I am looking for a reliable/simple setup, or, I'll stay with the stock LA batteries.

[dlentz]

You mean something like this?
[IMG][/IMG][IMG][/IMG]
Add a Junsi Cell Log 8s and you'll be good to go(so you can see the cell voltages. The BMS monitors the cells but has no read out.). What works for ME is: 4 Winston 700 amp cells, Cell Log Monitor, House Power BMS, Balmar 120 w MC614 Reg(main engine), Zena 150 Alt w Balmar MC612(DC gen), Sterling Pro Charge 60 (shore power).
I'm finding my pack is converging on voltage rather than diverging. Top balance your cells initially and you'll find the BMS becomes just another monitor. I have my BMS set to alarm for LVC and HVC the only loads/charging cutoffs it's capable of (at this time, until anything else is deemed necessary) is shutting down the main engine alternator (disconnects the "ignition lead" to the MC614).
I have all of my charging sources set at 13.8 v Bulk/absorbtion and 13.2 for float (still analyzing the float V) I find with this setup my cv=3.43 to 3.46 after a full charge, with the greatest imbalance going to 53 mv during charging. As soon as the pack is hit with any discharge the individual cells come back to within 3-6 mv. My Link 10, Cell Log, Inverter, all have alarms or LVC Plus all of these and the charge sources are only ran while onboard.
Some here will try to make you believe that using these cells is rocket science and/or dangerous voodoo only to be undertaken by the most mad of all lunatics. So I am not a rocket scientist and that only leaves the later. Unlike all of those who will chime in here, who have never had their hands on a LiFePo cell but read a "paper", I've experience a 700 amp cell shorted. I did it myself and it was no fault of the chemistry, and while it produces copious amounts of smoke and a bit of heat, IMHO it was way safer then the exact same thing in FLA. (the PVC case bursts (not explodes) from expansion and the heat didn't even melt the case)
Bottom line, IMHO, is that in "house service" it's just not that complicated. Although I grant that if I were going to sell or install these for someone I would approach it with all of the bells and whistles also.
Call me Mad, a Lunatic, a Fanboy, but call me a guy with a 700 amp LiFePo battery pack that's functioning. Oh my god the sky is going to fall and I'm going to H*** for sure. The armchair experts can rip me up now.
[IMG][/IMG]

[dlentz]

To answer your "alternator" question, you could probably get a shop to install a field wire loop outside of the alternator. Then you could use that loop to cut the field or at that point the best thing would be to convert to a programmable external reg like the balmar mc614.

I also went to the Sterling Prolatch relay as a ACR for my engine start bank (AGM), as it is programmable to a high voltage than the regular ACR devices at 13.3 v.

[bdbcat]

On the alternators...

I suspect you will find that 80A alternators, small case size likely, will not survive long producing 80A continuously into a LiFePo4 battery bank.

In contrast to LA, the LiFePo4 bank will absorb charge current at a prodigious rate, until almost 100% state of charge is reached. Standard alternators are just not up to that challenge.

I second the recommendation that they be modified to external regulation, and plan to run them at no more than 50% power level for sustained duty.

Dave

[boom23]

So, the biggest problem seems to be the alternators, which will be toast fairly quickly...

Which alternators work on the 4JH5 Yanmar engines (replacement for HITACHI LR180-03C) and survive LFP batteries?

Any other issues that I should be aware of regarding the Victron MultiPlus, Victron MPPT and S&W Hydrogenerator? Are the LVC and HVC triggers enough to deal with them?

Anything else?

[daddle]

A properly function alternator with internal regulation will not burn itself up under continuous load. They self limit their output based on temperature. Not so true with external regulation unless you have a remote temperature sensor.

[boom23]

Here is an interesting article about alternators:

http://www.sterling-power.com/images...r%20faults.pdf

[dlentz]

.

Which alternators work on the 4JH5 Yanmar engines (replacement for HITACHI LR180-03C) and survive LFP batteries?

Any other issues that I should be aware of regarding the Victron MultiPlus, Victron MPPT and S&W Hydrogenerator? Are the LVC and HVC triggers enough to deal with them?

Anything else?

As mentioned your alternators can work, but would be better with external regulation with temp monitoring.
Don't know specifically about your Victrons and S&W, but beware of products that have "lithium" settings. When I was looking most of those products had very high voltage settings for LI. On my Sterling Pro 60 I use the "Custom" setting programmed to 13.8 and 13.2. Also the Balmar Regs are programmable and have temp monitoring. You can charge at higher voltages, and it will drive amps faster into the battery, but you'd have to monitor the cell voltages so you don't go too high on them at the end. At 13.8 V for a termination voltage you'll be hard pressed to overcharge the individual cells unless they were WAY out of balance. And remember overcharging is not the end of the world, no cataclysmic events happen, you just run the risks of damaging the cell (maybe very little, maybe alot, depending on the severity). Kinda sounds like LA issues too, Huh? Jack Ricard has a very informative video about this on his site EVTV. Look for the video on charging LI Prismatic cells.
If you can program all of your charge sources at or around 13.8 pv (cv=3.45) your BMS should never have to do anything (3.8 cv= 15.2 pv). Actually if you run your pack between 13 v-13.8 you'll have 90-95% capacity and be far away from the knees on both the high and low sides of the charge/discharge curve. Winston cells spec'd at 2.8-4 cv or 11.2-16pv.
If your capable of wiring up the house power BMS, you can do this.

[Maine Sail]

Originally Posted by daddle

A properly function alternator with internal regulation will not burn itself up under continuous load. They self limit their output based on temperature. Not so true with external regulation unless you have a remote temperature sensor.

Not all dumb regulated alts have a regulator that also temp compensates.. Hitachi's do but many others don't. I have replaced many an alt that has literally cooked itself..

[roetter]

I am doing pretty much the same thing on a L450. Here is a preliminary diagram of my installation.
Screen Shot 2013-05-09 at 20.47.45 .png Views: 1623 Size: 108.2 KB ID: 60614" style="margin: 2px" />

Most of the time I will be charging from solar. The Outback is programmable so I should be fine. For safety I am using low-voltage-cutoff and high-voltage-cutoff plus cell differential from 2 Junsi cell loggers.

[roetter]

Originally Posted by Maine Sail

Not all dumb regulated alts have a regulator that also temp compensates.. Hitachi's do but many others don't. I have replaced many an alt that has literally cooked itself..

Does this (temp compensation) apply to the Hitachi 125A alternators as well? Should I use the HVC trigger from the Junsi to switch a relay that cuts the field to the alternator?

For LiFePo you really do not want a "smart" regulator it seems, just cut the charge when they are full - whatever that voltage may be for your definition of full.

[dlentz]

[QUOTE]

For LiFePo you really do not want a "smart" regulator it seems, just cut the charge when they are full - whatever that voltage may be for your definition of full.

Your diagram looks nice, but do you want to rely on a $30 cell logger for controls? You don't really need the multi stages of a "smart" reg, but one with programmable settings are good. Program your regs for day to day control of charging and rely on your cell log and BMS for malfunctions of your charge sources.

If you set your regulator (solar, alt, shore) with a low "float" voltage all charging is effectively cut off, I don't see the need to physically disconnect the charging in normal cycles.

When my shore charger drops to float (not the same as a trickle charge) the amps are zero and the voltage is below the battery so no potential there.

Your looking good there though, keep going.

[roetter]

[QUOTE=dlentz;1231901]

Your diagram looks nice, but do you want to rely on a $30 cell logger for controls? You don't really need the multi stages of a "smart" reg, but one with programmable settings are good. Program your regs for day to day control of charging and rely on your cell log and BMS for malfunctions of your charge sources.

If you set your regulator (solar, alt, shore) with a low "float" voltage all charging is effectively cut off, I don't see the need to physically disconnect the charging in normal cycles.

When my shore charger drops to float (not the same as a trickle charge) the amps are zero and the voltage is below the battery so no potential there.

Your looking good there though, keep going.

That is exactly my plan in the diagram. All charge sources will be programmed to a reasonable voltage with a really low float voltage. The Junsi's and the LVC / HVC solenoids are only there to protect against faulty charging sources or a total discharge because of some other failure.

Which one is the best suited alternator controller for this?
- programmable absorption and float voltages
- temperature compensation for battery and alternator

I would then additionally have the Junsi HVC signal cut the field to the alternators. Junsi HVC would then be about 0.2V above absorption.

[dlentz]

Originally Posted by roetter;1232120[QUOTE

That is exactly my plan in the diagram. All charge sources will be programmed to a reasonable voltage with a really low float voltage. The Junsi's and the LVC / HVC solenoids are only there to protect against faulty charging sources or a total discharge because of some other failure.

Which one is the best suited alternator controller for this?
- programmable absorption and float voltages
- temperature compensation for battery and alternator

Very good. The devil will be in the physical application.
The Balmar MC 614 has all of the above. You don't need the battery temp compensation though. It actually has a setting for "Halogen" that comes very close to a usable profile. You might need/want the centerfielder device to combine your twin Alt situation.

[ebaugh]

Originally Posted by roetter

I am doing pretty much the same thing on a L450. Here is a preliminary diagram of my installation.

Most of the time I will be charging from solar. The Outback is programmable so I should be fine. For safety I am using low-voltage-cutoff and high-voltage-cutoff plus cell differential from 2 Junsi cell loggers.

I looked at your diagram and see no major issues. You may suffer the same problem I do, my start batteries never get fully charged since the rest of the entire charging system is set to LFP voltages. Your isolators may accentuate this since the start battery is not "floated" by the LFP bank and will slowly self discharge between engine runs and then probably never get back to full charge. Consider moving the start batteries in front of the isolator to gain 1/2 volt or so for them.