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

[Cotemar]

T1 Terry,

What is the difference in the new LYP cells verses the older LFP cells?

[hellosailor]

Terrie, here in the US if you order x and the joker ships y, and there are differences in the two items, that's called "non-conforming goods" and while we've sadly stopped hanging, riding folks out of town on rails (that's split rails, pointy side up) and tar-and-feathering, shipping non-conforming goods sometimes means you can call the shipper back and say "Come and get 'em". Then after 30 days put them out on the doorstep with the trash and owe nothing. The laws vary, state and federal, depending on the situation.

I'd suggest Bob needs to call back the credit card company and say "they shipped something different, it isn't what I ordered, it isn't what they advertised, it isn't the same goods."

Three year old batteries...I'd wonder if they weren't USED somewhere, and just cleaned up real good before reshipping.

[deckofficer]

It looks like they were made April 26, 2010. Balqon's website quoted cycle life based on the old cells, so if they perform to that level I'm OK with such a small ($880) purchase being older cells. There will come a time when I'll spend some serious coin on 50+ kw-hr of storage and I'll do a better job of research.

[deckofficer]

They may be 2 1/2 years old, but Balqon did a great job of protecting them for shipment from Southern California to Northern California, don't you think? Others that have these cells, how were they packaged for shipment?




Packed tight with closed cell foam sheets.

[ebaugh]

I don't have pictures...but I had 48 cells shipped by truck from Arizona to Miami, then by partial shipboard container to Grenada. The only wood was the pallet they sat on. 12 medium boxes with 4 cells each, with similar Styrofoam padding in each cardboard box. The whole pallet wrapped in thick Saran wrap to hold it all together. After that trip one of the 12 boxes looked a little shabby, but the contents of that and all boxes were in good shape.

[T1 Terry]

This is how they are shipped from China I believe. As you can see, there are a few of the newer type cells amongst the older type cells. The other 3 boxes were all newer type cells. By clearing out my suppliers old stock I got the whole lot at a good price so I knew what I was getting, sort of, it's a never ending learning curve. Believe it or not I'm about to use the last 16 cells in a conversion of my smaller motorhome, then I'll need to buy more :lol:

The differences between the cells is the constant discharge rate 0.3C for the old and 0.5C for the newer cells, 10C pulse charge/discharge compared to 20C charge/discharge, 2,000 cycle life to 80% DoD compared to 5,000 cycle life to 80% DoD and the newer bigger cells are 7,000 cycles I believe. There is also a change in what the term constant charge and discharge, the old was some thing like 30 secs and the new is the same as continuous. Some of that stuff gets a bit vague as translations don't always mirror exactly what was said, sometimes the interpreters interpretation comes into it :lol:
As long as the charge/discharge demands are not greater than 0.3C these cells will be fine and give a long life, just the specs for the new cells aren't retrospective for the older cells.
I have 2 sets of 16 cells equalling 360Ah @12v (90Ah cells) 8 LFP and 8LYP, the idea was to see if they would work together, 3 yr old cells and 3 mth old cells. They have powered my house refrigeration and solar hot water control and pumps 24/7 plus a few other bits since June 2011, the last capacity test a week ago, after discharging all cells to 2.8v 710Ah came out and 713Ah went back in so there has been very little loss of capacity, possibly none actually because they may not have been 100% charged at the start of the discharge and I stopped charging as soon as the solar regulator dropped back to absorption voltage and then stopped charging, if I had waited possible the other 7Ah would have trickled in. They have had a few severe over voltage and deep discharges so I'm still quite pleased with their performance, I don’t use a cell balancing type BMS yet all the cells are still within 10mA across the pack until they reach 3.5v per cell.

The Sinolpoly cells are basically the same specs as the later Winston cells but they use a black case without the ribs so they are just a little smaller, unknown if cooling would be an issue with the lost ventilation gaps.

T1 Terry

[deckofficer]

I know this is silly, but I'm finding these cells to be quite photogenic. Must be the green in me, because I feel the same about solar panels.

Until yesterday I had never seen these cells in person, and I had a skewed idea as to their size.

[Lagoon4us]

Originally Posted by deckofficer

I know this is silly, but I'm finding these cells to be quite photogenic. Must be the green in me, because I feel the same about solar panels.

Until yesterday I had never seen these cells in person, and I had a skewed idea as to their size.

Photogenic??? Absolutely with the hot-rod as background!!!! Love it... LMAO

[deckofficer]

Originally Posted by Lagoon4us

Photogenic??? Absolutely with the hot-rod as background!!!! Love it... LMAO

I meant Terry's crate of cells. The hot rod and its stablemate is my non-green side.

[Lagoon4us]

Bob, all i can say is NICE!!!!

What site are you guy's using for the batteries? My source here is in Yugoslavia = a bit nervous...
Cheers

[deckofficer]

I used Balqon, but as mentioned waited 3 1/2 months to receive 2 1/2 year old cells.
Balqon - Advanced Transportation Solution

[T1 Terry]

I get mine from Trev in Far Nth Qld Basicly Natural He can do the strapping etc and has a good system organized for road frieght withing Aust but you would need to contact him regarding shipping off shore, he has been a very reliable supplier to date.

T1 Terry

[mcarling]

Originally Posted by Hyprdrv

when a large load is placed on the system, like a genset starting, the draw on the battery(s) can be enough to damage some sensitive electronics like chart plotters. Add loads like mentioned above and start the genset and it can pull down the voltage enough to kick off the Sensitive Electronics for a few seconds and restart.

Lithium Phosphate batteries have much more stable operating voltages than Lead Acid batteries, so the risk of damage to sensitive electronics from motors and generators starting or stopping should be much reduced with Lithium Phosphate batteries compared to Lead Acid batteries.

[hellosailor]

"when a large load is placed on the system, like a genset starting, the draw on the battery(s) can be enough to damage some sensitive electronics"
Not so. When a load is placed on the system, that can cause a voltage drop which will crash electronics but that won't damage them.
What damages them are the spikes thrown off when inductive loads "kick back", i.e. after a starter motor quits, it is briefly acting as a generator and even a small start motor like the one in a compact car can throw a 600 volt spike into the system. The duration of the spike is measured in milliseconds, but that's long enough to blow out electronic components what are onyl designed for "12" volt operation. With a larger starter, for a truck-sized diesel engine, the spike can exceed 2000 volts.
In theory any battery can act as a capacitor, absorb the spike, and protect all the gear. In practice? Spikes and surges, even ashore on home powerlines, are the biggest killer of electronic components including home appliances.
Electronics should always be offline when using start motors or throwing inductive loads on/off. Or protected by spike protection, but unforunately that's always a "consumable" component. In cars the electronics were normally protected by the time delay in the ignition switch (it takes longer to bounce back from "start" to "run" than the duration of the spikes) or by computer timing of that function for the new ones with a "start" button.
On boats? No protection. You just have to remember, do not start the engine unless the electronics are off, or protected.

[Hyprdrv]

And that is why I took the Genset off the House bank and dedicated a battery specificly to it. Now there is no motors on the house bank.
Steve in Solomons MD