On Friday, September 18, 2020 at 8:45:33 AM UTC-7, jfitch wrote:
It does not say that. There are exactly 10 exclusions in their warrantee, one of which is if you cycle it more than once per day for 10 years, they might exclude coverage. The word "capacity" in fact does not appear in the warrantee at all. "Defect" is a legal term in most states, not whatever you think it might be. I'd agree that it is really an 8 year warrantee, but in the deep cycle battery business, that is commonly referred to as 10 years, standard industry practice. I defy you to find an 8 year warrantee from anyone else.

Independent tests you can find on the web suggest that the reason they are comfortable making this warrantee is the battery starts with significant extra capacity over the label, to ensure that it maintains capacity for its life.

On Tuesday, September 15, 2020 at 7:58:30 PM UTC-7, 2G wrote:
On Tuesday, September 15, 2020 at 8:44:26 AM UTC-7, jfitch wrote:
Directly quoted from your own link:

"Dragonfly Energy Corp. (“the Manufacturer”) warrants each Dragonfly Energy and Battle Born Batteries branded Li-ion battery (“the Product”) sold by Dragonfly Energy, Battle Born Batteries,
or any of its authorized distributors or dealers, to be free of defects for a period of 10 years (“the Warranty Period”) from the date of sale as determined by either the customer’s sale
receipt, the shipping invoice and/or the battery serial number, with proof of purchase."

Between 8 and 10 years they will only repair not replace, which is the sentence you cherry picked. As I am sure you know, it is universal in battery warrantees to replace for a short period (typically a year or two) then prorate the remedy. Battleborn's warrantee is far longer, and far more inclusive than any deep cycle battery I have ever seen. Unless otherwise excluded (and it is not), a loss of capacity would fall under the legal definition of a defect. This is why in some industries (solar panels for example) the warrantee specifically allows 20% loss of capacity, excluding that as a defect.

On Monday, September 14, 2020 at 10:33:17 PM UTC-7, 2G wrote:
On Monday, September 14, 2020 at 6:09:49 PM UTC-7, jfitch wrote:
Not really. There is no exclusion for loss of capacity, there is an energy exclusion defined as cycling the battery more than 1 time per day for the warrantee period. That would be 3650 cycles in 10 years. I think I would be pretty happy with it if it failed after 3650 cycles. That would make it far cheaper than any L.A. battery in $/kW delivered over its life.

On Monday, September 14, 2020 at 4:13:06 PM UTC-7, 2G wrote:
On Monday, September 14, 2020 at 8:44:10 AM UTC-7, jfitch wrote:
Battleborn have a good reputation among the RV crowd. Also the only one that offers a 10 year (!) warrantee. The other high quality prospect is Victron, who do make a 200 AH, but it isn't drop-in in the sense that no other equipment is required. The Victron are intended for larger installations, so there is an external BMS and disconnects, all very nice stuff.. The Battleborn is "drop-in" if there is such a thing for LFP.


On Sunday, September 13, 2020 at 3:34:45 PM UTC-7, wrote:
On Sunday, September 13, 2020 at 5:02:14 PM UTC-4, wrote:
No one said Panasonic was an American company. It’s Powersonic we’re talking about.
I'm looking around for a large LiFePO4 battery for a non-soaring use, and there are many companies offering such, but I saw that several of them that are in some sense US-based say that their cells come from China, because currently ALL LiFePO4 cells are made in China.
Better read the warranty: it does not cover loss in capacity, which is regarded as normal use. It only covers defects in components or manufacture.
https://1t1pye1e13di20waq11old70-wpe...y-Warranty.pdf
I disagree - the words are VERY explicit:

Within the first 8 years of the Warranty Period, subject to the exclusions listed below, the Manufacturer will credit, replace or repair, if serviceable, the Product and/or parts of the Product, if the components in question are determined to be defective in material or workmanship.

And that is an EIGHT YEAR warranty, not 10 years. There IS NO coverage for loss of capacity.
Loss of capacity is not a "defect" - it is a normal consequence of use. It says so in their warranty.

Jon,

Those words are DIRECTLY from the warranty, so, yes, it DOES say that. In particular, they "reserve the right" to make the sole determination:

"The Manufacturer reserves the right to deny a warranty claim if the Product is determined, upon inspection, to be at its normal end of life even if within the Warranty Period."

Thus, the 10 exclusions (which is A LOT) IS NOT exhaustive, but exemplary.

To further complicate the issue, Battle Born does not publish datasheets on their batteries which might give some indication of things like the expected number of charge/discharge cycles. And they don't answer their phone (at least when I tried), so you can't get any answers that way.

Here is a good youtube teardown of a BB battery:
https://www.youtube.com/watch?v=G5E30u-66VI
He expects the battery to deliver 2,000 to 3,000 cycles, but I have found no actual testing that verifies this. The internal build quality does look good.

Another video actually shows an installed RV lithium battery system that lasted 8.5 yr and died because of a combination of design and user errors:
https://www.youtube.com/watch?v=0j0zcRXTDRk
They believe that the batteries would have lasted at least 10 years if these mistakes had not been made. They replaced the batteries with BB batteries which should not repeat these mistakes.

This couple taped an interview with the two BB principals, and at 29:00 they discuss the warranty (which is enlightening):
https://www.youtube.com/watch?v=g7BgRg6m_bY
The principal battery killer they identify is charging at more than a 0.5 C rate (that is 50A for a 100AHr battery). The previous video also identified heat. Also, LFP batteries can't be charged when it is freezing or below.

My expectations are that LFP will last a lot longer than SLA batteries, which I had to replace every 2 years, but I will believe it when I see it (the batteries might very well outlast me!).

One safety note: one of the videos used non-insulated tools while connecting up their batteries; if a short occurs at any point while making connections you will have molten metal flying out at high velocities. Be VERY CAREFUL while making these connections. One option is to wrap your wrenches with electrical tape or shrink tubing (insulated tools are VERY EXPENSIVE).

Tom