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Help DIY solar generator
#11
Sounds like you're talking about this:  https://www.batteryclearinghouse.com/pro...bulk-rate2

An excellent youtuber @DavidPoz did a 48v battery bank using several of these.  There are a series of youtubes to give you a good 'handle' on them.  Here's the first youtube: https://youtu.be/i_V8v4APT60  Several more follow that cover the complete build.

I think the rub with these is they test lower (from original specs) than people were hoping.   That doesn't mean (especially for the price) that they can't serve as an excellent DIY powerwall build with much life left Smile.
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#12
Close this is what I was looking at.

https://batteryhookup.com/products/byd-2...wh-blowout
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#13
I thought those BYD batteries are pretty decent until I saw the struggle DavidPoz has with them. First you need to find out what the capacity it is at and what they're claiming they have left. It's probably at around 65% of its full capacity. That in itself isn't great. It leads to issues like imbalance between the cells. DavidPoz spent time trying to balance them by linking them all together. The other issue are that the packs are welded together so rearranging each cell to get a nice pack is difficult. So you might need something like an active balancer that will keep the cells constantly in line. Some EV packs are like this so it does make it challenging to reuse them.
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#14
Is there a specific battery you'd recommend?

swampf0x
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#15
(10-01-2020, 05:44 PM)swampf0x Wrote: Is there a specific battery you'd recommend?

swampf0x

BatteryHookup is one of 'the truthful' / trustworthy sources - I've ordered 6,000 cells from them over 3 years.   However you have to read plainly and not get to excited...  (which I've done myself to my own shagrin). Smile

They say in the description....
"....If you get a module that tests 4 kWh that's a bonus. But we are pricing these as if every module was 50% of original capacity. ...."
and further down
".... We are not guaranteeing capacity but we tested a lot of these and realistic expectations are between 2.75-3.75 kWh out of the original 5.2kWh. ...."

So they are being forthright that these are in the 50-60% SOH range.     This is similar to the info we got on the @DavidPoz / batteries I referenced above.   
 Agree with @not2bme warnings.    For a budget, it may be OK for you there are risks - maybe buy a couple 'extra' so you can discard a really bad one of the group.


Recommendations......
Its tough.    Patience is good and keep checking key sources.     

Maybe consider Lithium-ion, like these https://batteryhookup.com/products/compl...20ah-880wh     BatteryHookup says "....We tested a dozen of these and they still have around 90% or better capacity ..."   which is fine (in my opinion) for lithium ion.    I believe this tear-down youtube will give you insight into how to use them / maybe reconfigure into 14s  - https://youtu.be/aZOpdxRCpOA     

You could buy brand new LifePo4 such as BattleBorn or something like that.  There's a channel where the guy reviews *many* LifePo4 cells and batteries you can checkout ...    @DIY Solar Power with Will Prowse     Can help you get a perspective on newer cells / pricing so you can judge better. 
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#16
How about one of these https://watts247.com/product/pip-3048lv-mk/

Along with 12 of these https://batteryhookup.com/products/compl...20ah-880wh

And then I can add 6 solar panels like these https://www.solarelectricsupply.com/sola...olar-panel

I can build my own racking system once I get measurements. I can program it to turn on my generator when it gets to low

Would that make a good long lasting setup?
Did I miss any parts?
Could I get the 26% tax credit on all parts?


Looks like DavidPoz prefers the all in one now.
This set up would cost around $3000 if I don't need any more parts.
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#17
12s is not 48v most of its range is under 48v. The max and for most 48v inverters is ~60v min ~42v the one linked is 64v max 42v min
Missing BMS.

Later floyd
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#18
(10-02-2020, 04:39 PM)swampf0x Wrote: And then I can add 6 solar panels like these https://www.solarelectricsupply.com/sola...olar-panel

This set up would cost around $3000 if I don't need any more parts.


If you're on a tight budget you can try looking at used panels on ebay.
https://www.ebay.com/itm/Used-250W-60-Ce...2614945473
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#19
(10-02-2020, 06:01 PM)floydR Wrote: 12s is not 48v most of its range is under 48v. The max and  for most 48v inverters is ~60v min ~42v the one linked is 64v max  42v min
Missing BMS.

Later floyd
The youtube above shows that these can be taken apart and configured into 14s.   12 of them would be 144 cells, so 10 x 14s with 4 cells left over - and would be 10kwh battery bank.

(10-02-2020, 04:39 PM)swampf0x Wrote: How about one of these https://watts247.com/product/pip-3048lv-mk/

Along with 12 of these https://batteryhookup.com/products/compl...20ah-880wh

And then I can add 6 solar panels like these https://www.solarelectricsupply.com/sola...olar-panel

I can build my own racking system once I get measurements. I can program it to turn on my generator when it gets to low

Would that make a good long lasting setup?
Did I miss any parts?
Could I get the 26% tax credit on all parts?


Looks like DavidPoz prefers the all in one now.
This set up would cost around $3000 if I don't need any more parts.
Overall - you always need 'more parts'     BMS, hardware, wire, electrical boxes, conduit, circuit breakers...   $1000+ - hard to guess without a lot more detail of your plans/situation Smile

>Would that make a good long lasting setup? 
Here's the famous, optimistic, Battery University chart (https://batteryuniversity.com/learn/arti..._batteries) that many of us are hoping is true for lithium-ion Smile


These Mercedes batteries are lithium-ion (rather than LifePo4) so they will not last as long as LifePo4.   In my case, I run lithium-ion but my battery is double-size so I can maintain a low 50% DOD with hope of many 1,000(s) of cycles (light blue line in chart above - %75-25% DOD range).  I am up to 800 cycles so far with no noticeable degradation - so things are looking good but the data is just sketchy.      

If you do moderate DOD (70%?), then maybe 10yrs for these lithium-ion since they are 'auto based' and auto typically shoots for 10yrs with 80% capacity left.   There's likely some literature on the expected life of Mercedes Batteries.

 "Long lasting..." is in the eye of the beholder.    If you pay 1/2 price for 10yrs, you can buy 2 sets of batteries over 20yrs...   many factors.
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#20
(10-02-2020, 06:41 PM)OffGridInTheCity Wrote:
(10-02-2020, 06:01 PM)floydR Wrote: 12s is not 48v most of its range is under 48v. The max and  for most 48v inverters is ~60v min ~42v the one linked is 64v max  42v min
Missing BMS.

Later floyd
The youtube above shows that these can be taken apart and configured into 14s.   12 of them would be 144 cells, so 10 x 14s with 4 cells left over - and would be 10kwh battery bank.

(09-30-2020, 04:08 PM)swampf0x Wrote: I've watched some you tube videos but haven't run across what I'm looking for. Everyone wants to use 100s of small batteries welded together. I want something easy to build, quick to build, and powerful enough for the above. Portable would be nice but not a have to have item.


thanks,
swampf0x
I was just going by what was stated in the first post. Easy to build 2 24v LiFePo4 8s batteries just need to be connected in series that would be both easy and quick to build. hooking up the Bms wouldn't be hard either. you should have a 5 kWh battery. with just two batteries So 4 could give you up to 12 kWh. The cost is comparable with the LiFePo4 being quicker to have up and running. 1199.88 Mercedes LG vs 1100 BYD LiFePo4
Later Floyd
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