Is Li-ion now viable for off-grid?

[Mike90250]

Call up the 2 golf courses http://www.destination360.com/centra...belize-golfing and see if they use batteries in their carts or if they are gas ? If battery, there is your source for cheap lead acid. I agree the supply chain is very different when you are off the main path, but if I was doing what you are doing, I'd even use parallel strings of golf batteries before I tried LFP.

[miahallen]

The golf-carts on Belize use gas. Even if they did use FLA, I would need at least 4 strings of golf cart sized batteries (6V 220AH)...which you all had advised me against in the past (balancing problems).

I could get Deka L16 (370AH) locally from the auto parts store for about $435 US each. That is my best cost for FLA....however, I would like high capacity. Using 6KWh per night doesn't allow for any extra days of autonomy with a 370AH pack. I'd really need two strings...about $7,000 USD (12KWh at 30% DoD). I just got a quote for the 16KWh Li-ion pack for est $7000 after importing...So, to my sensibilities, cost is still in favor of Li-ion.

[Sunking]

I could get Deka L16 (370AH) locally from the auto parts store for about $435 US each. That is my best cost for FLA....however, I would like high capacity. Using 6KWh per night doesn't allow for any extra days of autonomy with a 370AH pack. I'd really need two strings...about $7,000 USD (12KWh at 30% DoD). I just got a quote for the 16KWh Li-ion pack for est $7000 after importing...So, to my sensibilities, cost is still in favor of Li-ion.

I assume those are Deka 8L16, 6-volt 370 AH batteries. At $435 per battery is a Kwh cost of $197.72/Kwh which is high, but you are Belize. At 6 Kwh per day you would need a 30 Kwh. In practice 48 volts @ 740 AH. That works out to 16 units x $435 = $6960 The Deka is a 4 to 5 year battery.

$7000 for a 16 Kwh Lithium is $437/Kwh and I can tell from that price is a Chi-Com CALB, Winston, ect 100 AH cells. Just about the same price we pay in Panama and what they pay in the USA because they are imported from China. a 2-3 year at best battery. To be equal usable capacity of the Deka requires a 22 Kwh LFP. 16 Kwh i snot going to cut it especially in Costa Rica. That would be 48 volts @ 500 AH or a 16S5P battery (80-cells) Those CALB 100 AH cells cost $135 to $150 each. You would need 80 cells x $130 = $10,800 to $12,000. Then you are going to need a BMS on top of that and for 16S that has HVC and LVD add another $750 to $1000.

Look you need to be honest with yourself, use real numbers, and make Apple-to-Apple comparisons. Me, I could care less about you, and if you make a huge mistake is your problem. So here is some apples to consider.

Deka 8L16's x 16 Units is going to cost you some $7000 and last at least 4 years if you learned your lesson. That works out to around $1700 per year.

or

Calb 100 AH cells x 80 units plus a BMS is going to cost you some $12,000 and will last 2 to 3 years if you do not make a mistake. That works out to around $4000 per year.

[adoublee]

We have recently installed 10 LG Chem batterys, 8 out of the 10 were dead on arrival, we thought it must be our guys stuffing it up but we got in the most respected solar guy in the state to hook up a few of the replacements and we did everything exactly as he did, turns out they were knackered. Dealing with LG to get the replacement batteries has been a very painful experience. We are thinking of a LG ban they suck.

Willing to provide any additional information on the LG Chem batteries now that you've had a few more weeks to watch them operate and LG is formally advertising their launch? Did you use 400V or 48V flavor of Resu battery? Any other information on what the issue was with bad units (cells, firmware, DC converter)?

[miahallen]

Well, I do appreciate all of your input guys. I ended up buying some 800AH 2V Deep Cycle AGM cells from NPP Power in China:

http://www.nppbatteries.com/static/ueditor/php/upload/file/20161122/1479785681670436.pdf

This bank is oversized enough that I should stay below 20% DoD 90% of the time, so I'm hoping to get good life out of the bank. Also, they will end up costing me only about $5500 USD total for the 48V bank. Maybe when this bank dies in a few years, I'll revisit the Li tech option

[reed cundiff]

We are at 4 1/4 years with LFP on our 5th wheel with no noticeable reduction in charge capacity. System has been to Yucatan twice and Canada once. We primarily boondock and roads have not been optimal. Did 14 Weeks in Labrador/Newfoundland last summer to include 600 to 700 miles of gravel that was execrable to OK in LFP battery bank In Roadtrek. Then did 14 weeks in Mexico to Yucatan, Chiapas, Puebla, and then West Coast of Mexico. There is no reduction in charge carrying capacity. 5th wheel was left two winters at son's place at 7800' in mountains of northern NM where temperatures dropped to -25 F. Battery suite was disconnected and nothing untoward occurred.

Equivalent battery banks for 5th wheel would have weighed 600 to 800 pounds which would have exceeded king pin specifications. Equivalent for Roadtrek would have been 400 pounds which would have been approaching posted weight carrying capacity of the Chevie frame.

I am a retired senior physicist from Army Research Labs and understand science quite well.

Reed

[max2k]

...

I am a retired senior physicist from Army Research Labs and understand science quite well.

Reed

then it should be obvious to you that claiming 'no noticeable drop in charge capacity' requires some hard numbers to back it up? 4.5 years is respectable service life so public wants to know.

[reed cundiff]

You curiously have no problem with the statement "..If you had LFP for 3 years you would be looking at replacing them soon. There is no better option than FLA batteries. FLA's are tough as nails and can take a lot of abuse. One mistake with LFP and they are done. ." but find it difficult to accept that we find no noticeable drop in charge capacity. We ran the air conditooner on 5th wheel for 4 hours recently and got it down to 50% SOC as a test. It was fully charged the following day (4 kW-hrs deficit).

It is to be noted that the folks at Technomadia did have a serious drop in capacity when they spent several months in Phoenix in summer parked on tarmac. Their LFP battery suite was in an unventilated box in direct sunlight. Temperatures would have gone far above those where damage can be done. A lot of us have learned from Cris's innovations and from his mistakes as well. LFP must be kept above 0 C for charging (0.01 C is permissible but chancy) and below 46 C. We never plan to spend time where it gets above 46 C.

[max2k]

You curiously have no problem with the statement "..If you had LFP for 3 years you would be looking at replacing them soon. There is no better option than FLA batteries. FLA's are tough as nails and can take a lot of abuse. One mistake with LFP and they are done. ." but find it difficult to accept that we find no noticeable drop in charge capacity.

depends who states that- SK has been around batteries a lot more than all of us combined. While I do realize he can't physically keep up with every development out there I usually pay attention to what he says. If he'd lost a battery like you describe and decided to share the experience he'd state what killed it accurately- if it was temperature it would be concrete number along with hours of exposure if it was charging voltage you'd know the value and it would be measured accurately so you could trust it and avoid the same mistake yourself. When it comes to statements like yours I have to work out the numbers myself and even that is full of assumptions: sounds like your AC discharged battery by 4kWh and it was 50% SOC (based on what criteria?). Now, to make it useful it would help if you could share details about your bank: manufacturer, date put in service, rated capacity, voltage, use pattern (may be you are using it 10 times a year) charge/discharge currents used so curious minds around here could see some picture.

[sensij]

Now, to make it useful it would help if you could share details about your bank: manufacturer, date put in service, rated capacity, voltage, use pattern (may be you are using it 10 times a year) charge/discharge currents used so curious minds around here could see some picture.

Curious minds would have already looked through the forum history and seen many of those questions have already been answered.

[karrak]

If my memory serves me correctly, which might not be the case, I think my LFP based off-grid system is similar to Reed and Elaine's. I have been logging data about my system with its ~9.5kWh Winston LFP battery and ~1140W of solar panels since October 2014, I installed the battery in April 2013. My system is in continuous use and has been since it was installed.

Average Energy Cycled Through Battery Per day: ~1.9kWh (last 19 months)
Average Energy Use Per Day: ~2.9kWh (last 19 months)
Max Charge Current: 47.8A (~0.13C)
Max Discharge Current: 247.7A (~0.69C)
Lowest SOC%: ~8% (April 2017, from cell voltages calculated about ~5% left in battery)
Average SOC%: ~77%
Overall Battery Energy Efficiency: ~96%

If you want more information have a look at the posts by steveg on his 7+ year old LFP battery, or go farther afield to other forums. All these sources back up Reed's and my story.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor
Latronics 4kW Inverter, homemade MPPT controller

[max2k]

If my memory serves me correctly, which might not be the case, I think my LFP based off-grid system is similar to Reed and Elaine's. I have been logging data about my system with its ~9.5kWh Winston LFP battery and ~1140W of solar panels since October 2014, I installed the battery in April 2013. My system is in continuous use and has been since it was installed.

Average Energy Cycled Through Battery Per day: ~1.9kWh (last 19 months)
Average Energy Use Per Day: ~2.9kWh (last 19 months)
Max Charge Current: 47.8A (~0.13C)
Max Discharge Current: 247.7A (~0.69C)
Lowest SOC%: ~8% (April 2017, from cell voltages calculated about ~5% left in battery)
Average SOC%: ~77%
Overall Battery Energy Efficiency: ~96%

If you want more information have a look at the posts by steveg on his 7+ year old LFP battery, or go farther afield to other forums. All these sources back up Reed's and my story.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor
Latronics 4kW Inverter, homemade MPPT controller

thank you- this is what I was looking for, quite impressive.

[JSchnee21]

Willing to provide any additional information on the LG Chem batteries now that you've had a few more weeks to watch them operate and LG is formally advertising their launch? Did you use 400V or 48V flavor of Resu battery? Any other information on what the issue was with bad units (cells, firmware, DC converter)?

I'd also like to hear more about the LG Chem batteries for residential storage. This is one of the few viable commercial platforms to complete with Tesla other than perhaps Panasonic (if they get their act together). Perhaps this should get bumped into a separate thread.

80% infant mortality seems almost unbelievable for this fairly expensive product from a reputable electronics company like LG. Granted it's early days, perhaps some early MFG issue, faulty component, or bad software.

Sorry, I forgot to include Sonnen

http://news.energysage.com/tesla-powerwall-vs-sonnen-eco-vs-lg-chem/

[Amy@altE]

I just visited FireFly Energy yesterday who makes the BattleBorn Batteries in Reno, NV. They are worth looking into. LiFePO4 for safety and light weight (31 lbs for 100Ah 12V!), very advanced BMS built in. Much less expensive than the SimpliPhi.

[reed cundiff]

Can probably get information similar to Simon's from our Magnum monitor. We are full time RVers' and basically, we have used LFP/solar systems daily for 4.5 years except when we traveled to Central and South America by air. Left 5th wheel at son's place at 7600' in mountains of northern NM where temperatures got down to -20 F (-29 C). Batteries were disconnected. We have not gone below 47% SOC.
Reed and Elaine