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To me the term "drop-in" means the cell-level data from the BMS is not accessible at all, no way to see how the balancing is progressing etc.

Pretty sure none of the Victron packs are like that, data is always exposed to their monitoring ecosystems, and likely the pack's operation subject to their control as well.

So, "packaged system" is the term I'd use across the board.
 

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Cape Dory 30
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If you are going to pay for Victron, follow their recommendations for your target voltage and Ah capacity.


Find a good dealer with experience in your use case. Otherwise you are getting all the hassles of DIY without the cost savings!

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Propulsion is an entirely different arena from House bank storage

really should not be mixed up in the same thread.

Same with drop-ins compared to LFP generally, just leads to too much confusion.
You are right, the thread went pretty sideways from the get-go. When all the OP asked was opinions on pay more and buy local or less online. :)
 

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To me the term "drop-in" means the cell-level data from the BMS is not accessible at all, no way to see how the balancing is progressing etc.

Pretty sure none of the Victron packs are like that, data is always exposed to their monitoring ecosystems, and likely the pack's operation subject to their control as well.

So, "packaged system" is the term I'd use across the board.
Victron: 12,8V & 25,6V Lithium SuperPack - Victron Energy

Lithionics has one also: 12V 125AH G31 Battery | Lithionics Battery

I suspect they wanted to have a foot in this market segment.

Mark
 

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Dumbed down, such an unfortunate trend.

But I can see the marketing advantage.

I see even BB as way overpriced, I'm sure these are better quality cells internally, so even pricier. More likely to be around to honor the warranty I suppose, that's a huge part of what you're paying for.

Since quality deep cycling lead banks are readily available locally in the U.S. at ~$1 per Ah

Anything more than 7-8x the price even taking usable Ah into account, I just can't see making sense.

Only where the greater energy density is of high value, like racing yachts, very fancy camping rigs.
 

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You are right, the thread went pretty sideways from the get-go. When all the OP asked was opinions on pay more and buy local or less online
It takes a certain level of knowledge just to be able to ask a smart question.

Being exposed to the tangent "side chatter" is part of the process of getting noobs educated.

If they were willing to develop their google fu and spend a few man-weeks reading the past threads, that would accelerate their climbing the learning curve.
 

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Cape Dory 30
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It takes a certain level of knowledge just to be able to ask a smart question.

Being exposed to the tangent "side chatter" is part of the process of getting noobs educated.

If they were willing to develop their google fu and spend a few man-weeks reading the past threads, that would accelerate their climbing the learning curve.
Agreed.
 

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Weight is of high value to multihull owners. Our boat instantly became 700lbs lighter.

Mark
Yeah I was going to say, I replaced my car battery with a Lithium Iron... it's 9lbs now instead of 35! That's got to add up tp huge numbers on a bigger setup.

Sent from my SM-G975U using Tapatalk
 

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I dont understand...indications
I check cell voltage with a multi meter. Thats all


I assume if you are able to check each cell you have a home built lithium pack and you are measuring the cells at times to evaluate their proximity to each other in voltage to attest to the health of your battery pack?

For instance when my truck house battery gets to 12.2 I know it is time to charge it. If you are on a boat full with solar time and use less amp hours per day than the solar can produce I can see the need for no BMS. But a cheap Columb meter will at least let you know state of charge, so I added one to my system.
 

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My belief of not needing a bms is...
1..the cells are close enough to equal
2..i dont test their differences at upper and lower ends

When charging via solar or alt, or recently after charging, virtually no cell is reading the same. Never hitting the top means they are always accepting more when being charged and resistances are different.
 

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I assume if you are able to check each cell you have a home built lithium pack and you are measuring the cells at times to evaluate their proximity to each other in voltage to attest to the health of your battery pack?

For instance when my truck house battery gets to 12.2 I know it is time to charge it. If you are on a boat full with solar time and use less amp hours per day than the solar can produce I can see the need for no BMS. But a cheap Columb meter will at least let you know state of charge, so I added one to my system.
While a BMS could provide voltage and amperage data, not all of them do. A separate battery monitor is always a good thing regardless, and they shouldn't be confused because the purpose of a BMS is functionally completely different than a battery monitor.

Mark
 

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If a bank needs balancing, even if only once a year

the only voltage (SoC%) where they will be closely matched

is the point you chose for balancing.

So with top balancing, the cells will look unbalanced in the middle ranges, and more so at the bottom.

And all that is as it should be, inherent to the process.
 

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Then either you're balancing at more than one voltage point (a waste of time)

or the pack is healthy and well-matched, thus no need to balance at all.

It's simple math, how balancing works, you can't actually alter the capacity of the cells, you'r just choosing the relative SoC% to get the voltages lined up

so that pack-level readings can be more useful (safe) at that SoC point.
 

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After initial top balancing i gave away the 20a power supply.
Other than being fed by alt and solar, theyve not been touched in 3 years...other than multi meter reading
 

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If a bank needs balancing, even if only once a year

the only voltage (SoC%) where they will be closely matched

is the point you chose for balancing.

So with top balancing, the cells will look unbalanced in the middle ranges, and more so at the bottom.

And all that is as it should be, inherent to the process.
You have equated matched SOC% with matched voltage, and this isn't correct. The cells in a bank will be most closely matched in voltage at the middle ranges. They will be most closely matched in SOC% at the balancing point.

For example, below 13.6V, our cells are all within 3-5mV of each other. Above that, the differences climb up to 30mV at 14.0V.

Mark
 

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Sorry if I did not make clear, I meant at rest.

My banks are never above 3.35Vpc, Full 100% is usually 3.32-3.33V depending on brand.

Yes during charging once you get above the knee of the curve (IMO not a good idea for longevity, nor usually is top balancing) then deltas widen.
 

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One thing one learns very quickly down here is that a normal warranty isn't worth the paper it would be printed on by your printer.
If something important fails and you want to take advantage of the warranty, you often have to ship it back to the manufacturer, and depending on how much and how soon you need it back, that can either take a lot of money or a lot of time. It's often just easier, faster and cheaper to buy a new one from a local outlet at outrageous prices.
So, when I think of spending 10 to 12 grand on a complete Life4PO set up, batteries, invertercharger (5kw) solar and an MPPT, etc.. I'm looking at 800 amps of 12 volts, with 60 to 80 amps of solar.
Perhaps it is worth getting what I need through a local retailer who will honor the warranty. Is it worth the extra 2 grand to have a local dealer with spare parts in stock and within 50 miles or so of me, and not go through all the research and doubt if where I'm purchasing my batteries is a reliable supplier?
Any thoughts?
It is very much a matter of your own comfort and technical knowledge in electrical systems and of course your available time. For me, being an Electrical Engineer (as part of my far away studies and practice...), setting a new battery bank system is not a big issue, but for sure I had to learn a lot, as the whole entry of the LFP batteries into our arena was new to me. If you hire a local pro shop the cost could easily be 2-3X or more in comparison to your own sourcing of the materials alone. If you add the labor it will probably add another few thousands to the bottom line.

The advantage for me in building my own system is also with the ability to identify and fix issues much faster in the years to come, especially while cruising in remote areas. I keep one spare 3.2V 280A cell.
 

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“ . . . cut our diesel use to less than 100 gpy”

Let’s say this cuts the diesel usage to 1/3 (saving 200gpy). I’m very much in favor of solar and wind, but how many years will it take to recover the $10-$12k?

Well the cells need to be replaced by/before then?
 
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