Battleborn vs AGM costs per WH video

[evm1024]

Not sure how many have seen this. It looks to be well done and if you dispute the conclusions the data is available to check.

https://www.youtube.com/watch?v=iy3hga_P5YY

[rgleason]

Thanks evm1024

The full report https://mortonsonthemove.com/best-rv...-test-results/

[Orion Jim]

Not very helpful when he chooses not to divulge the brands tested other than the Battleborn he appears to be promoting.

[Adelie]

I started watching it and when he refused to name brands I was done. Also seemed like it was going to be almost a promo for BattleBorn.

I did a cost analysis of major plug-n-play LFP batteries and FLA, AGM & Gel batteries by the major brands.

For cycle life I gave them the benefit of a doubt and gave all the LFPs 10yr/3650 cycles. Claims of 5000 to 15,000 are outlandish, and the research I've done in the last 2 days since I produced the chart below indicates they are unlikely to even reach 10yr. The problem is both the cells and the electronics. Frankly I think the electronic BMSs that are integral to these batteries is the weakest part. Regarding cell life, most of the research I found shows LFPs don't like very high (3C) or very low (0.5C) charge-discharge rates. Unfortunately none of the research I've found does testing at normal RV or sailboat charge-discharge rates (0.03-0.10C). When I hit the lottery, I'll pay to have that testing done.
For AGMs I said 1,000 cycles even though 700 is more likely.
For Gels I said 1200,
For FLAs I most indicated 1,000 but gave the Carbon-FLA's 1,200 or 1300 despite them claiming 1900ish.
Lifelime and Optima didn't make claims about cycle life, so I used 600-700, but they are probably less if discharged to 50%DoD.

For Firefly I used the manufacturer's data of 65%DoD and the mid range for cycle life on their spec sheets for that DoD.

I obtained data for nominal voltage, amp-hr at the 20hr rate, normal DoD, cycle life and what I could find for prices. Using that data I calculated how much energy you would get out of the battery over its entire life and divided by price. Results are in the BLUE column with units of Whr/$


Best bang for the buck was Trojan FLA golf cart or Solar batteries. That was partly because the local distributor here in San Diego has really good prices. Even without those prices they were still significantly ahead of the LFPs.

The down side is that you need to check the cells for water level monthly unless you install an automatic watering system. And there is a nuisance tax of having to remove and replace the battery bank twice during the 10yr period the LFPs are assumed to last. Really, it'll probably be more like once in the 7yr the LFPs will last and maybe less than that.

In the YELLOW rows I compared the best Solar battery, cycled to 27%DoD which claims 3650cycle life and the DIY battery system NewHaul installed on his boat. If you go DIY you can get LFP prices way down and they might be cheaper than FLA if you can get the 10yr life. But you are committed to designing and maintaining the system yourself and the suppliers are off-brand suppliers in China. I'm actually looking at doing that to put together a dinghy battery where weight would be a bigger concern than on the mother ship where weight is less of an issue.

[bstreep]

One of the 2 brands was Lifeline. I recognized the top. I think it's AGM2, as I recall. We did the math on our Lifeline AGMs. We got about 4 years over the last 2 sets. At $1000 a pop (8D), and we have 2, we dove into the lithium pool. If the lithium lasts 10 years or more, we'll be ahead. We'd also switched our refrigeration and freezer over to 12 volt systems, so we really needed some more capacity, and we don't really have the room. I mean, sure we could have made more room, but the 5 lithium batteries plus an AGM start battery fit perfectly where our 8Ds did before. We will let you know how things go.

[jeepbluetj]

To somewhat echo what Adelie points out.... How many golf carts are there in the world? (vs seriously cruising sailboats)

There's a ton of golf courses. They have tons of carts. $$$ is very important to the bottom line. What do they stick in those carts? Yup. Best bang for the buck batteries. If LiFePo was overall cheaper, I'm sure golf courses would go that way. (They will, when the tech matures a bit more) Most courses charge the carts overnight, then all the next day they just run em to the ground. Amazingly deep discharges. (I've walked the 17/18th hole playing twilight because of a dead cart many times) Plugem in, and let em rip for the next day. They'll get a few years out of a set of batteries for each cart.

GC2's people. Cheap as cheap gets. Very long life. A normal human can lift one (unlike 4D or 8D... my new boat has a pair of 4D AGMs that I'm terrified of how I'm gonna get em out when they die)

[Adelie]

Yeah, that was something else I looked into, what do golf courses use for their own carts and what do most warehouses use for their forklifts? FLAs. There was almost no penetration by anything else. I think warehouses are sniffing around LFP for special uses but are mostly sticking with FLAs.
May be different in 5-10yr.

I had all this in a post in the last 2weeks. I’ll try to find it. Tomorrow.

[evm1024]

I'm getting closer to my 7th year on a set of Winston 700 AH grade B cells.

Mostly I short cycle them and leave them partially charged for weeks at a time.

Then there was that time I used them to start the diesel. They were around 20% SOC as I recall and the started had an internal short. The fully charged AGM starter battery would not turn the engine over (But it would run the inverter with a 1500 watt load). The house bank started the engine and got us home.

[bstreep]

Originally Posted by jeepbluetj

To somewhat echo what Adelie points out.... How many golf carts are there in the world? (vs seriously cruising sailboats)

There's a ton of golf courses. They have tons of carts. $$$ is very important to the bottom line. What do they stick in those carts? Yup. Best bang for the buck batteries. If LiFePo was overall cheaper, I'm sure golf courses would go that way. (They will, when the tech matures a bit more) Most courses charge the carts overnight, then all the next day they just run em to the ground. Amazingly deep discharges. (I've walked the 17/18th hole playing twilight because of a dead cart many times) Plugem in, and let em rip for the next day. They'll get a few years out of a set of batteries for each cart.

GC2's people. Cheap as cheap gets. Very long life. A normal human can lift one (unlike 4D or 8D... my new boat has a pair of 4D AGMs that I'm terrified of how I'm gonna get em out when they die)

COMPLETELY different scenario. See, golf carts aren't purchased by the clubs. They are leased. After the lease is up, they go back to the manufacturer, who refurbs them for sale into the secondary market. Usually after 1 or 2 years. There is ZERO incentive for them to use anything but a good reliable battery that will last 3 years. That's it. They want them to last long enough to get through the lease, and then through the secondary sale. A mile from us is a golf cart company. They get in 2 or 3 truckloads of carts every day, that are refurbs.



As a former golf cart owner, I'd jump on lithium in a second. 1/2 the weight and twice the capacity? Oh hell yes. I don't want to be stranded. Remember what it's like when your house bank or start battery gets iffy, and you are constantly worried if it will last long enough? Get stranded in the South Texas sun on a ranch once or twice. If I'm going to keep it 10 years it makes absolute sense.