Thanks Steve. I appreciate the encouragement. Warning, I do enjoy a slight deprecation of intent. It makes the story more interesting (to me anyway
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I couldn't speculate on cost. It really is location dependent. Where I am, I saved a few thousand dollars over any other option (by size from 3 to 5k? By original budget I'm a bit under. And with 2.5x the capacity). There are benefits to being diy and an early adopter. smile. I have yet to sell off all the replaced assets. But having sold some of them; right now I sit somewhere below $155/kw. Installed.
From what I've read I was not "lucky". My experience seems to be standard. What was lucky was finding the battery pack at all.
I didn't spend much actual time on dis/reassembly. It occurred over two weeks/a month primarily as I had other obligations. I would do it exactly the same way if I had to do again. Of course, being my second time, the schedule would be greatly compressed. smile.
There were no specialized tools. I used a 10mm socket head on an electric drill and a voltmeter. I also used a socket wrench with a 10mm socket. Oh and some screwdrivers/pry bars. All pretty standard stuff.
To charge I was very fortunate that I have two Morningstar ts-mppt-60s. And two 1kw panel sets. This allowed me to use one controller/set for test charging the lithium batteries. And I was able to keep my electrical system online while I did so. It also allowed me to flash eeproms. Set new previously unheard of charge control limits etc with the security of knowing I had a fall back position.
For SESS (solar energy storage systems) I don't believe a BMS is necessary in the short term. And I have a month and 120 kws of power created and distributed to back that up.
In the long term I do believe that a BMS will be a good idea. Simply for peace of mind. If you can monitor your batteries online. Hopefully from a remote location as I travel a fair bit. This would be a good thing.
Also. If I was going to use more of the battery I would want better control. Charging to 80 and discharging to 30% offers a huge high/low safety net. I may want to go higher this winter when the days are short. A sunny day to 4.1 per cell vs 4 would give me another day of cloudy weather storage.
As mentioned. The inverter will shut down at 3.2v/cell. The solar controllers not only charge to a set point that has proven accurate. But there is a high voltage disconnect setting.
Safety - Its the same with any wiring you do. House. Battery. Car. Stereo. There are more dangerous jobs that I do. My tractor can easily do great damage. My tablesaw. Chop saw. Cook stove. Vegetable slicing.
Measure twice cut once. Look up and live. Etc. I imagine here we are talking to the converted. DIY demands clear thinking.
If I was to do it again I would make better protection for the cell bus bars. And probably wrap the handle of the socket wrench. Bicycle tube would work well methinks. Hmm. Think I just added something to my "still to complete list."
And yup. It turned out that the solutions I needed were accessible from online resources. Primarily from the electric bike and rc crowds. Also, early on GM released more info and there were some neat presentations given. Clues were found!
There was also some good info from other folks who have tried similar things. Nobody who did exactly what I did. But close enough. I was able to share with some of those folks too. Which feels good.
My explorations with Morningstar have always been rewarding. They are great folks to work with. And I appreciate their help. Plus. To be able to reprogram a 5 year old controller to an entirely new chemistry. In large part due to Morningstar continuing to update software and firmware for these products. Speaks very highly for them.
A tip of the hat goes to my buddy John. I'm not an electrical wizard. And I usually have to do things a few times before it "clicks." So having him help out was good.
<B>All the pointers here</b> were really helpful. You'ze all made things easier for me. Much appreciation.
While I'm handing out kudos I'd better mention my girlfriend. She who rode in the truck. She who listened to untold hours of ideation. Maybe we should have a moment where pause in celebration of our significant others
You know. I guess us DIYers are like bulls in china shops. We charge in where others fear to tread. Sure, there's an element of original thinking / solution creation in what I did here. But its not the first time. I mean I over paneled my solar panels to controller initially because it made sense. later the idea was supported "officially." I put my panels on dock hinges for seasonal adjustment. Still one of the best ideas I've seen for mounting small panel sets. Cheap. Strong. Durable. Efficient. Proven particularly useful in the winter. Who knew?
And of course there are tonnes of great ideas on this site. From you folks who have done the same. Charge on! (yes that is a deliberate pun)
Huzzah!
Creeky. The somewhat knowledgeable about one fragment of the lithium solar world.