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

[T1 Terry]

No fight picked Lloyd, I was just interested in what the cells were and what condition. As you say, it's an unknown quantity from a bell up company so it doesn't actually instill a great deal of confidence.
If we were talking about a big capacity battery pack of known brand cells like either Winston or Sinopoly and the price was right, I would have been very interested.

No harm done.

T1 Terry

[senormechanico]

I'm looking to purchase 8 400 aH LiFePo4 cells for my home's backup power system.
Has anyone purchased from this company?
Their 400 aH ThunderSky LiFeYPo4cells go for $430 each.
Shipping is 10% of purchase price.

Alliance Renewable Energy, Inc

[hellosailor]

Steve-
I may have this all mixed up, but I thought from what I had read that Thundersky was borged into another company slome time ago, and that Winston Chung's company was now selling these batteries exclusively through Balqon in the US market. You might want to check on what's going on with Chung's companies, the mergers, and whether the Thundersky brand is being resurrected, or are very old batteries. I thought the Thundersky brand was gone...but could easily have that wrong.
If the price is right and the batteries are all same source same age...You know, just use a credit card in case there are delivery issues like Bob had.

[Lagoon4us]

An update, our 4x400 amp Winston Cells (consecutive serial numbers and built this year) without BMS but only one source of charge (solar) have not strayed in their individual voltages by more than .01V on one cell.

Cells were delivered 75% charged with no voltage differences at all and that's the way they've stayed for 28 days now cycling as the sun sees fit......

750 Watts of solar keep up with our req's nicely.

The LA's are probably fishing line sinkers by now.....

[deckofficer]

Lagoon4us, So I'm guessing your liking these cells?

[Lagoon4us]

So far so good, maybe the secret is one charge source only, right now they are sitting at 75% and the sun has come up so the charge cycle commences, today by lunchtime they'll be topped up.
I just went down and checked each cell (as i've done 4 times a day for last month) and they are reading 3.32/3.32/3.31/3.32 The .01 difference hops from cell to cell at different times, my multimeter is a reasonable unit and i can put it on an individual cell twenty times and still get the same reading.

Yep we like the lightness and no gases generated is a bonus. Acceptance of a solid charge is so much better i hated seeing the lead acid charge curve tapering off a resource simply because of the lead acids resistance....

When the sun shines we are making hay, can't get better than that!

Cheers.

[deckofficer]

Because of that charge acceptance, no gassing, and cycle life, they are finding use in the high end gringo homes in Baja, Mexico that are off the grid and gets drenched with sunshine. I'm looking at homes down there on the Internet and some of the homes are running enough solar and these cells to stay during the hot summer and running the A/C. These will be the users that will be able to tell us that they do indeed have the advertised cycle life, but it will take them 10 years to get those cycles.

[Lagoon4us]

Australia outback has a high use of remote pumps and communications. The huge banks of glass cased LA's are extinct....

I'll come back to this thread in a month and relate our experience again...

Frank

[downunder]

Originally Posted by Lagoon4us

So far so good, maybe the secret is one charge source only, right now they are sitting at 75% and the sun has come up so the charge cycle commences, today by lunchtime they'll be topped up.
I just went down and checked each cell (as i've done 4 times a day for last month) and they are reading 3.32/3.32/3.31/3.32 The .01 difference hops from cell to cell at different times, my multimeter is a reasonable unit and i can put it on an individual cell twenty times and still get the same reading.

Yep we like the lightness and no gases generated is a bonus. Acceptance of a solid charge is so much better i hated seeing the lead acid charge curve tapering off a resource simply because of the lead acids resistance....

When the sun shines we are making hay, can't get better than that!

Cheers.

Good to hear they are going well, fanbol.

[Lagoon4us]

Ok we just had two days of cloud cover which has resulted in our 400 ampere bank dropping to 185 amps stored.

The cloud is 70% cover still and we are facing the wrong way totally to get some light on the panels until later in the day due to the light prevailing winds.

Now i just connected (temporarily) the main engine alternators to the Lithium and we shifted anchorages, during that shift those alternators whacked in 86 amps @ 13.60 volts at the battery bank.

My question is, 'If when the bank has been fairly depleted is their any issues in doing what i've just done bringing the Lithium bank to say 350 amps and switching off the alternator charge'?

Individual cell voltages are within .01 of a volt still and this difference moves from cell to cell from time to time.

Cheers Frank

[goboatingnow]

No issue. Once your above the LVC , you can charge hard. Below the LvC , I would suggest a pre qualification charge

Dave

[Lagoon4us]

Thanks Dave i'll fit a link switch and use the alternator boost when needed.

Other than dealing with the cloudy days the cells are working well with the solar.

Cheers

[T1 Terry]

Just keep an eye on the cell voltages, stop if a cell reaches 3.6v. as soon as you stop charging the cell volage will drop down, it's just the high rate charging that would make it climb rapidly at the end of charging. If you just want to put a bit in to carry you over to the next sunny day, that works fine as well. That is the great thing about these batteries, they don't need to be fully recharged, just enough to cover the amount used until you can charge them again, by what ever method is available.

T1 Terry

[Maine Sail]

We are having the opposite problem in that our bank charges sooooo fast when we run the motor it is almost always in the 95-100% range as a SOC.

I even dialed the field % back in my regulator to allow the alt to run "full on" for those times when I do let the bank get down to 80% DOD. This lack of acceptance limiting, compared to LA, is amazing. There is some "limiting", if you can call it that, as you approach target voltage. Our bank is set for 13.8V, but still well into the high 97%+/- range the bank is still taking 70A +. When it tapers it does so over about a 10-15 minute period down to 4-5A. It is at that point that I will cut my regulator manually.... Because these batts don't "need" to get back to 100% like an LA does, I could care less about that last .5% of charge...

I will be fitting a regulator cut off switch at the engine panel so I can let the bank actually do what I paid for, cycle.. Even with the very short amount of engine running we've done this season the bank takes current so fast it has barely been below 80% SOC more than twice and then we run the motor and she's right back into the mid 90's....

The bank is pretty much 100% unaffected by our on-board loads. Yesterday I was running the Espar, 12V refrigeration, every cabin light, the inverter to power a MacBook Pro, the stereo, cell phone amp, VHF, wind, depth speed and the voltage never even dropped a 100th of a volt from resting..... Simply amazing....

I've not yet even turned on our solar panel and honestly doubt we'll even need it except when at anchor, in the same spot, for multiple days at a time........... Takes a bit to get used to compared to LA. It is a totally different mind set, but a good one..

[Lagoon4us]

Agree today i've bought a battery isolator so i can bring on the alternator or battery charge as needed/available or required then isolate it allowing the bank to be used from say 90% or let the solar top it up with the nights draw nicely cycling the bank.

I think Maine may have pointed out previous that the natural charge/discharge of solar is good BUT for those day's of nil sunshine a hit of well managed alternator or charger amps is the go.

YAou don't have to sit with 100% charged banks....