Battery bank nearing the end.

stillchillin

Hi all, looking for some opinions on battery bank replacement. I currently have a 12 year old set of 12 Rolls 4-KS-25PS. They have served me well and would replace them with the same in a heart beat. My hesitation is I may not live here 12 more years. I am looking at a Fortress Lithium battery bank maybe 3 10KW modules. Twice the price of the Rolls, which by the way are the same price as I paid 12 years ago. Thinking the maintenance free batteries will be a selling point when and if I put my house on the market. I am way under paneled if I understand the charge rate correctly 150 amps, I see 70 amps on the best days.
Thanks, Stillchillin

Dave Angelini

You really think the battery will help sell?  If someone wants an offgrid home they pretty much will take what is there.  I have had some issues with fortress clients.  Offer to teach the new owner how to maintain the Surrettes is my vote. I would have a spare for the Magnum also.  Good Luck !  

SumPower

After maintaining industrial forklift batteries for years, I have been leaning to the new technology of faster charge rates. 

Maintenance free is a good selling point as well as the high charge rates.

My opinion is you can pay more for the the Lithium Irons, and not have to deal with batteries drinking gallons of water and having to verify specific gravities. Tedious maintenance routines.

I tend to be more in the Lithium camp anymore as they are proving themselves in real use.

JRHill

"I am way under paneled if I understand the charge rate correctly 150 amps" **

To me a MAJOR advantage of LFP04 is they don't care about charging and discharge rates. You will need to un-learn some lead battery habits with LFP04. The biggest concern is that your charging sources can be adjusted to accommodate the low & high voltage cut offs because those are killers and no Absorb or very little. The FM80 is good with LFP04 but I don't know about the Magnum.

Another thing to un-learn about LFP04 is their voltage range is really flat so you can't tell your status by voltage like you can with lead. But you have a battery monitor that is a coulomb counter(?) so you might have some adjustments to make there for reality and reset/calibration.

Since the beginning of our off grid project a goal was to have as simple a system to maintain as possible in case something happened to me and the wife had to cover operation. Since I went LFP04, everything battery related is off the table. No more summer/winter adjustments, no SGs, no water, no corrosion. As it is now the only thing she has to do is start/stop and maintain the daily generator runs in the winter if I wasn't involved.

Previously I had a 48v bank of L16RE-B that were retired at end of life (2nd set) and I replaced them with 3ea Simplify 3.8-48. Within a month (winter) I was surprised and impressed but if one failed I wouldn't want to run with just 2 while the gods of warranty coverage pondered the issue (one of my carry on issues from the days of lead batteries). **So I added a 4th. I am 'over-batteried' and they have an easy life operating between 90 down to 60% SOC. They are in their happy place for longevity. I suspect they will outlive me. If I do anything it might be to charge them fully during the winter in case I had a generator issue so I could go 2 days, but I do have a 2nd generator like you do so that is not worth it so I keep the same setting year around. While I can still move I handle the generator and carrying firewood to the house. I let the wife shovel the snow and feed the livestock. Good trade 

My LFP04 blocks are about to start their 4th year and there is NO difference in operation. I know they are there and working because I go by them every once in a while and the lights stay on at night.

stillchillin

Thank you everyone for your input/opinions. I thought I would get two different camps on this one which is why I reached out. I did not mention that I had a lazy cell since day one and if I would have known then what I know now I would have tried to remedy it then, It is the only cell in my bank with low SGs and low voltage. The question is do I go one more winter or replace the bank now. Dave I like the way you think and I am leaning torwards the Surrettes. My bank typically uses about 2.5 gallons per 5 weeks but that has increased by 1 gallon recently. I suspect the one bad cell has caused the outback to overcharge the rest?
Thanks again for the input

Dave Angelini

Thanks it is not just the way I think, it is the sum of hundreds of clients doing this. I am still learning also! Offgrid home sales work best when eyes are wide open.

On the bad cell, I have seen this go for 3 or 4 years before it escalated. Just watch it and have pilot cells to make it easier. When you see the pilots start changing SG, you know what to do. Even then, you can probably always make it through winter with increased charging.

Also the Surrette AGM is one of the best in the world and will stop the maintenance. LFP as long as it has a company with deep pockets, that will be there is a good choice also. Just have seen too many LFP companies go adios. Why would you pay the premium if there is no warranty. They can really make sense if you depend on a genset and can get your electronics closed loop with the BMS. Over 30% fuel savings closed loop. Can't use Outback for this at this time. Hope they really open up soon!

JRHill

"...Over 30% fuel savings closed loop. Can't use Outback..."

Well said. I had chosen OB for my platform from the beginning. I can't even remember why but it probably leaned heavily on the system's ability to interconnect the inverter CC and control them from the Mate (system monitor) in a convenient place instead of getting into the crawl space each time. When the Mate3 came out and then OpticsRE (real time internet status and ability to modify parameters) the interconnection really became of value.

But that whole time to date the world just seems to pass by OB by as other mfrs added important features, capabilities and support for newer technologies like LFP04. Even for bug fixes that took forever just for them to contain new bugs. All I can say at this point is that I can only hope that whatever comes out of this most recent company change that they get much more responsive and become competitive among their peers. I may even stay with them in the event that I am forced to replace any major components.

BTW, there is a recent sign of new life which was an OB Tech Support guy who introduced himself to the OB forum has actually posted into some threads in a helpful fashion:
https://forum.outbackpower.com/viewtopic.php?p=107811#p107811

I sure hope this continues.

Dave Angelini

Me too! Still have a few outback clients. I see you on the Outback user Forum. Been begging them to update for a long time. Back to 2005 when the MX 60 was all I used, for awhile...   Crossing fingers!

stillchillin

stillchillin

Better safe than sorry, ordered these Rolls 4-KS-25PS batteries during the labor day weekend and just received in perfect condition unlike the first set. Packaging was awesome, last set came on 2 pallets with plastic wrap holding them on the pallet, the pallets were soaked with electrolyte and 2 caps were missing and one battery had a forklift hole in it. Much improved! Thank you NAZ and Rolls