LiFePO4 - The future for off-grid battery banks?

[skinnyandpauline]

Panasonic Corporation has announced it will commence mass-producing a compact long-life lithium-ion battery system for home solar power applications this month.
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The Panasonic battery system includes a management unit designed to control charge and discharge of the battery. The system can store surplus electricity generated by rooftop solar panels for use when needed, further reducing the dependence on grid supplied power.
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The lithium-ion battery has a design life time of 5000 cycles, based on an 80% depth of discharge per cycle. This compares very favourably to traditional deep cycle battery technologies such as AGM (Absorbed Glass Mat) and gel; which may only have a serviceable life of 1,500 cycles when discharged to 80%. Sounds like Lithium Iron is gaining popularity and credibility.

Local solar provider contacted me this week to discuss installation of what appears to be this system. He's coming to quote on 1 May so I'll update this post when I know what he suggests as a package and also what its going to cost. In Australia we have different energy rates dependant on the time of day you use the power. 2pm to 8pm ...peak period ...costs me about 55 cents per kw/hr. The idea is to use the battery power during peak periods. (the highest cost period). Sounds like a plan

[inetdog]

Local solar provider contacted me this week to discuss installation of what appears to be this system. He's coming to quote on 1 May so I'll update this post when I know what he suggests as a package and also what its going to cost. In Australia we have different energy rates dependant on the time of day you use the power. 2pm to 8pm ...peak period ...costs me about 55 cents per kw/hr. The idea is to use the battery power during peak periods. (the highest cost period). Sounds like a plan

Even with a $.55/kWh cost at peak times, up until now the cost of a time shifting system, including frequent battery replacement, has calculated out to $1/kWh or more. Be very suspicious of his figures.

[spacevoyager]

Hi,

Has anyone run across an inverter/charger designed to charge lifepo4 batteries?

Thanks,
Zak

Yes, we have developed a charge controller and bms System special for LiFePo4 and LiFeYPo4.
If you are interested have a look on our website.
www dot ecs-online dot org

If you have any quesions, about it, feel free to ask us

regards
Falko Jahn
ECS Team

[bonaire]

Everyone who uses RC hobby products these days (car/plane) uses power inverters and chargers and most support LiFEPO4. It's not too long until this stuff goes large scale and are offered for off-grid applications. Sometimes, I wish they had used LiFEPO4 for the Boeing Dreamliner 787 rather than Li-Poly from Yuasa.

[inetdog]

Yes, we have developed a charge controller and bms System special for LiFePo4 and LiFeYPo4.
If you are interested have a look on our website.
[URL omitted.]

If you have any quesions, about it, feel free to ask us

regards
Falko Jahn
ECS Team

Much as I appreciate the reference, Falko, the moderators will see it as a violation of the no advertising, no links policy. If you can restate it as a suggestion for a web search rather than a URL is might be acceptable, but probably not.

[Beanyboy57]

Yes, we have developed a charge controller and bms System special for LiFePo4 and LiFeYPo4.
If you are interested have a look on our website.
www dot ecs-online dot org

If you have any quesions, about it, feel free to ask us

regards
Falko Jahn
ECS Team

Victron energy also have products for lithium charging and management.

[spacevoyager]

Much as I appreciate the reference, Falko, the moderators will see it as a violation of the no advertising, no links policy. If you can restate it as a suggestion for a web search rather than a URL is might be acceptable, but probably not.

Ok, sorry. I did not know, that it's not allowed.

Regards
Falko Jahn
ECS

[inetdog]

Ok, sorry. I did not know, that it's not allowed.

Regards
Falko Jahn
ECS

No problem, it has been taken care of. Welcome to the forum.
My biggest interest in Li at the moment is in following the Boeing 787 debacle. I am sure you have some opinions on what happened.
The design looks like it was done by somebody who did not really understand LiCo and none of the individual cell voltages were recorded, or even left the BMS inside the battery case.
I have much better feelings about LiFePO4.

[bonaire]

Do you mean the original Boeing battery design did not have have cell balancers built into it? After a number of cycles, the cells would get out of balance and, obviously, you get a cell being overcharged and thermal runaway. You'd think that Yuasa or someone with any battery system construction experience would have done cell balancing and voltage monitoring per-cell. There are 13 year old kids playing with RC cars who know that multi-cell packs need balancing.

[SunEagle]

Do you mean the original Boeing battery design did not have have cell balancers built into it? After a number of cycles, the cells would get out of balance and, obviously, you get a cell being overcharged and thermal runaway. You'd think that Yuasa or someone with any battery system construction experience would have done cell balancing and voltage monitoring per-cell. There are 13 year old kids playing with RC cars who know that multi-cell packs need balancing.

Or someone at Boeing trying to cut corners to save money and believed a salesperson when they said the battery was a plug and play and wouldn't need to worry about it for 5 years.

[inetdog]

Do you mean the original Boeing battery design did not have have cell balancers built into it? After a number of cycles, the cells would get out of balance and, obviously, you get a cell being overcharged and thermal runaway. You'd think that Yuasa or someone with any battery system construction experience would have done cell balancing and voltage monitoring per-cell. There are 13 year old kids playing with RC cars who know that multi-cell packs need balancing.

It does contain active cell balancing. But only a controlled shunt around each cell activated by high voltage. No detailed feedback to the separate charge controller unit and no record of individual cell voltages. Individual cell temperatures were not even monitored. The current capability of the shunt is seriously limited by the size of the wires to each cell.

The protective contactor that disconnects the battery from the charger in the event of over voltage, under voltage or overcurrent is a normally CLOSED contactor opened under battery power. I suspect that this may be what causes the battery to require replacement when it is over discharged, since the protective circuitry (contactor coil) will continue to draw power until the battery is irreversibly drained. Unless it gets to a maintenance facility before then.

The company that contracted the whole battery and charger system and the company that built the charger both sub-contracted the testing to Yuasa, the battery manufacturer, since they had no idea what to test.

Yuasa did not have much if any experience with the use of that size battery in an aircraft where it is subject to large air pressure cycles as well as wild SOC swings.

Finally, the charger supplier was very proud of their patented method of predicting end of charge that meant that they did not have to continuously monitor the battery voltage!!!

Visit PPRuNe (Professional Pilots Rumor Network) for a lot more information and speculation on the whole subject. There are two active threads:

http://www.pprune.org/tech-log/512398-787-batteries-chargers-part-2-a-3.html

and

http://www.pprune.org/rumours-news/505455-faa-grounds-787s-89.html

[Sunking]

Anyone found a good place to buy new batteries?

Wallmart sells batteries for cheap.

[bradash]

I'm looking into buying new batteries

My 3000 Ah battery bank is getting pretty old and will not hold charges for very long anymore, so I have started looking to replace all the AGMs with something else. I was thinking about trying LiFePO4 but have not looked into if it will work with my inverts yet.

Has anyone thought of using a fuel cell?

[inetdog]

Has anyone thought of using a fuel cell?

You mean a combination of a fuel cell to produce electricity and an electrolyzer to produce fuel? Storage of the hydrogen is a big problem.

[SunEagle]

You mean a combination of a fuel cell to produce electricity and an electrolyzer to produce fuel? Storage of the hydrogen is a big problem.

I just heard about a different type of fuel cell that uses natural gas instead of hydrogen. These units are being used by a medical company B&D out in California.

I don't have any details but it sounded interesting.