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I purchased a 14s Overkill BMS very recently under the belief that my battery bank was LiFePO4... big newbie mistake documented here on this forum with little help or recognition from this board of my error (I own the mistake... but my assessment is true). Luckily OverkillSolar has been...

@zanydroid Thank you for your detailed thoughts. I know it took a good amount of time and energy to reply to my questions and I appreciate it! There’s a lot to consider. I’m going to be looking for deals and see what other projects I can group with this since it’ll involve opening a wall and...

Thanks for feedback. From what I’ve gathered to this point, the right inverter will prevent backfeeding when the grid goes down Re: @Hedges ”Anti-islanding prevents export when grid goes down.” Aside from that, I’m on NEM 2.0 and exporting is acceptable.

Can’t disagree with you on this.

Option 3 seems like the way to go. If zero export is enabled that would mean I wouldn’t be in danger of backfeeding during an outage, right? Or do the EG4s have a smart setting preventing this even with limited export setting enabled?

Great to know, 400bird. I just got off the phone with SolarEdge, and confirmed optimizers are required on each panel. Seems like a money grab, but good to know there are some operative reasons for them aside from panel-level monitoring. Thanks for your insight. Also, sadly, I spoke with my city...

Just for my clarification: moving all circuits to another panel would be a subpanel - but I’d be using it as a main panel, right? Are there any limitations to using a panel downstream from the main panel? Understood. Will it attempt to export energy to the grid in this scenario? Or would it...

Beautiful! Thanks for your succinct answer. Edit: Follow-up question With your recommended configuration- it seems the critical load panel would essentially be reliant on off-grid power. How would you configure the panel to be backed up by grid if batteries are depleted and the sun isn’t out?

You all may be right. It's easy enough to get an owner-builder form - they're available online. However, this is what the people at the front desk told me. I'm just leery of going against the grain when I'll need permits approved and inspections passed. If I was a pro or, at least, had...

San Mateo Co.

I recently received 8 Lithium Ion NMC battery packs. Here are the battery specifications. Each cell labeled: - CA1 060G6 - +3.7 V - 37.0 Wh - 10000 mAh - BM1740310368 Some of these tested at 12V and some at 16V. Each cell is labeled as 3.7 W nominal, however, some of the cells are testing at...

I'll need some time to chew on some of your advice - seems quite complex. But good idea with freelancing schematics. I hadn't heard of Greenworks before, so something to look into. In the meantime, here are some photos of current components. (The interior area has sence been finished with...

Another one that'll take some time to process. Thanks for your insight!

No worries! I'll look more into my historic peak usage to see if I find any red flags. Thanks for your condolences!

Yeah, my municipality has a reputation to uphold. I might be able to subcontract out the work but then may as well hire out the whole project. So, back to square one..... Solar installation companies gouging customers to capitalize on the NEM2 ---> NEM3 deadline. Worst-case scenario, I keep my...

It looks like I wasn't clear with how I listed my options. The plan in each case is to move my circuits to a subpanel that'll act as my new main/critical load panel. This was described in C) (Proposed location of new 200A Subpanel / Critical load panel for full home backup) The question is how...

This sounds like quite a project! Congrats on nearly being finished. Be careful with diy PV jobs that involve mounting on the roof and/or adding panels - my understanding is it can void original installer warranty and technically can knock you out of NEM 2.0. On another note, I also have a...

Thank you for this detail. I suppose, in theory, if I ran all loads through a separate off grid system, the original interconnection would export close to 100% of all PV generated energy. This would at least guarantee a $0 True-Up. The other big issue I haven’t figured a solution to is...

Thanks! Was looking for something like this. Will dive in.

Thank you for that insight, BentleyJ. I think you’ve got a point. Perhaps getting the project approved through PG&E should be my first priority and tackling the building dept. can be a battle for another day. Just seems like obstacles keep popping up and I’m allowing that to take the steam out...

Awesome. Thank you!

Thanks for advice NVS, Issue I'm having is individually charging 56 * 8 (448) cells. I'm trying to find the best way to do that, which I haven't yet found through YouTube or Google. Being new at this, and dealing with 56 cell packs, I haven't been able to figure out the safest and most...

Not a joke... just sarcasm. Option 3 seems to be my best bet if I want to keep throwing money at the issue.

That's an option for sure. I'm in contact with Renvu / illumine-i regarding plans. Don't know how much this option will cost me yet though.

Thanks for your reply @BentlyJ. You confirmed all my fears regarding building out such a system. Is it absolutely necessary that there be a permanent coupling? I’d like for the off grid system to be able to operate independently on demand. This brings me to another hard issue you answered-...

My understanding is, to stay under NEM 2.0, I can modify/add to the system up to the current inverter (perhaps even swap it out), but I cannot change the size of my array. Off grid sounds great in theory, but I’m not sure how I’d configure an off grid system and still maintain power export from...

Anecdote: I once went to the building department to ask a question. They told me I'd need a permit and a licensed electrician to change out a single outlet.

Although the product name implies it's a solar ready device (Square D SR69064A Csed Solar Ready Kit). My understanding is that it is simply a Feed Through Lug, functioning as a Line Side Tap - which is common in many panels that are not marketed as Solar-Ready. The best part with this design is...

Thanks for your reply @ A.Justice. Best news I’ve heard today. Either I misinterpreted the DIY Battery Handbook or the information stating that top- balancing needs to be done on cell-by cell basis. While prepping the battery banks last night it hit me…. These cells are already wired and ready...

There lies the difference between NEM 2.0 and 3.0. If I understand correctly, under NEM 2.0 you are credited at the same rate the energy was generated. With 3.0, you’re credit at the utility wholesale rate (which, I’m sure is adjusted to fulfill their needs vs. the customer’s). This is...

After a long time lurking and YouTube watching, I haven't been able to figure out a few things. I'm hoping one of you could help shed some light. Thanks in advance! I have an existing solar array and would like to upgrade the system for following reasons: Cover all energy needs (currently...

Greetings all. I wanted to see if someone out there would be able to give me some input regarding the subject line. Background: I have an existing, underpowered system with utility interconnect agreement. The system was installed it approx. 2018. - SolarEdge SE5000H - 3.71 kWp array - Average...

Insightful! I appreciate your feedback, Zanydroid. A lot for me to think about.

I’ve got to look more into directional boring. But trenching seems to the only other option.

Thanks for your reply! I read through your thread with Hedges a couple of times over. The lack of wired conductors between the meter and main had me stuck for a while until I discovered feed through lugs. They cost around $130 at big stores which seems like overt gouging - but found it cheaper...

Great points! I don’t disagree. Issue is I have this grid tied system that I’m still paying off. I want there to be some benefit to it. Even if I don’t run my loads through it, under NEM 2.0, I’m still getting credit for exported energy. So, I’m just trying figure out the best way to keep...

From my understanding, the feed through lugs on this model will need to go above the main breaker - making the conductors energized regardless of the main breaker position. See last picture: D) Main Lug Feed through (@ Red Circles) There’s also a video link of the installation - which seems to...

All understood! Thanks again.

Question. With the batteries pictured above, is it safe to use that thin of wire for BMS connection? I just received Will’s recommended DC charger, and a 48V Overkill BMS will be in tomorrow… so I’m getting close to having what I think I’ll need to get started. These batteries aren’t the...

Really have been trying to avoid this inevitability. Just as I was with the critical load panel… Now look at me… gonna have to do both. Or, nothing at all.

The steady voice of reason. I hear you! I don’t think my backyard would be compatible with such a large array, though. My 3.7 kWp covers only 40% of my energy usage. Meaning I’d need something 2-3x the size. I want to be able to use my backyard for living. However, as DIYrich brought up, I...

I have these very batteries! However, for the life of me, I can't figure out the best way to put them to work. Plus... I'm concerned about storing them in my home because of the chemistry. I'm brand new at this, so may just be over-precautious. Check out my post regarding this subject: Battery...

I'm running into an issue with these batteries and hoping that someone can help me out. - I'm trying to top-balance these batteries (is this really necessary)? - The only way I'm aware that I can avoid charging the cells in this pack 1 at a time (56 cells per pack x 8 packs) is to put them in...

Confirmed today by seller. These are Lithium Ion batteries. Not Lithium Iron Phosphate. This was a $2k+ mistake if I can’t find another use for them. Does anyone have suggestions? Note: I expect the temptation to want to flame me for this blunder. Just keep in mind, it’s a mistake I...

The meter and main panel are integrated.

I was able to track down more details about battery packs I acquired but could not figure out how to use. Each pack comprises 56 prismatic cells but looks like it can be broken down into smaller pre-fabricated sections for 28. With buss bars in series: Attempting to charge to 3.7V when I...

Is anyone aware of an alternative company to Unbound Solar? Seems that their service would be a great fit, but, according to the rep. I spoke with, they require you to order all parts from them exclusively and you must order a complete system. I'd just like plans and some help through the...

Thank you. This clears things up quite a bit - I may have gotten carried away with this CSED meter/main separation issue. Plan would be to: 1) reassign current CSED as main disconnect 2) remove all loads from CSED 3) add a 200A breaker 4) feed conductor from 200A circuit to hybrid inverter...

Perhaps, but only about 40% of my energy usage is powered via PV generation according to all the data the utility is sending me. Peak time of use falls between 1600 and 2100 every day… that might be where they’re getting me. Also, I gave an average, with outliers removed. My highest month was...

Hey all, I'm located in SF Bay Area. I purchased these batteries, thinking they were LiFePO4 (yes, newbie). I'm open to sell or trade for LiFePO4 for a solar project I'm embarking on. Details below: Manufactured by Cummins for EV testing (minimal use per report) Model BM44E Battery...

Awesome. DM incoming. Thanks.

Keeping grid connection. I just realized I left out an important detail and should go into more detail on this. I’ll add this detail to original post. Thanks for the great question @ SolarFlares!

Thanks, @Hedges. Found websites, don't see anything ready for residential consumers yet. Will be following!

@adriansantos Any updates? Have you found any other answers to your questions? You're further along than me, but I have some of the same questions, especially regarding safety.

@wargames I have 18kW worth of NMC batteries. They were made by Cummins to test EVs.

I'm in California and looking to upgrade my solar array prior to NEM3 going into effect (4/14/2023). My system is 3.71 kWp and covers approx. 50% of my energy needs - leaving me with a $400+ true-up bill at the end of the year. The current system comprises: Inverter: 1 x SolarEdge SE5000H-US...

I was thinking the inverter would be powered by the battery bank? But… I think this actually is an alternative solution to my #3! CT = external energy meter, right? I want to avoid this at all costs! Great to know I can charge batteries in such a way. This would simplify things as it...

Edited for clarity: Coupling configurations… This where I become confused and lost in the reeds. I can’t visualize how I’d do this. A disadvantage I see is that these solutions would void my installer’s warranty… (whatever that’s worth).

@ A_Justice. Thanks for clarification and advice. Yes, please share the thread you’re referring.

It's funny how complex things seem as a beginner. I hope I can look back at this post 1 or 2 years from now and laugh at how clueless I was when writing. I was over-eager. I couldn't see past the $0.13/kWh pricetag.... and now I have 16.5 kW of LiFePO4 power. You'd think I'd be happy, right...

Gotta admit. If I wasn’t doing business with such a reputable energy utility, in the great state of California, … I’d think I was being scammed. I tapped in to review my SolarEdge energy production and it looks like you’re right on point. It seems there should be no way I’d owe so much on...

Hey all, I'm working on a plan for a grid-tied system for a friend: He wants a large system so my initial recommendation was : 1) EGG-FlexBoss21 Inverter 2) EG4-GridBOSS MID V2 3) Pallet of 31 x Aptos 440W Bifacial Solar Panels (Black) | Up to 550W with Bifacial Gain | DNA-120-BF10-440W (13,640...

Question, in the picture below, how would you go about testing whether or not you can use these wires (red box in the picture below) for an initial Top Balancing? Each pack has 56 cells and there are 6 bundles of 4 strand wires coming from each pack. I just want to be cautious so that I don't...

Grettings all, This is a follow-up post to a thread I started a while ago (Off-Grid Home Backup - California). Thanks to the resulting answers and advice I received, I've come up with the following configuration guidelines. The purpose of this post is to clean up any potential safety concerns...

Edit: AIO = All-In-One. Disregard previous statement that the technology was over my head. Thanks for sharing your thoughts on this issue.