# Battery Replacement / Upgrade



## Steve_S (Feb 25, 2015)

Good Morning folks

I've reached a point where I want to upgrade my existing battery bank and am considering various options (more available now than 5 years ago ! ). I am looking at LifePO4 and Li-Ion variants and budget of course is a driving issue, to that end I have no issues with DIY'ing a setup and upcycling of EV batteries etc.

Current Pack I want to replace (will go to the greenhouse) is 8x, Rolls Surette S-550, configured series - parallel for 24VDC (956 Ahrs - 20kwh gross / 428 Ahrs - 10kwh useable @ 50%dod) 

New Pack considerations: 24VDC, at least 10Kwh but preferably 12-14 kwh or 300-400 Ahrs with either LifePo4 or LiIon. Either with internal BMS or with a readily available BMS for the pack.

Any suggested Vendors or Supplier's would be greatly appreciated, Availability to Canada of course is a must in my case. The timeline is not critical as we are at the figuring it out & thinking on the budget for doing this upgrade.

Thanks in Advance for any assistance
Steve


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## JeepHammer (May 12, 2015)

Depends what your DIY requirements are for me, cost vs life cycle.
I snagged LiFePO4 batteries used for cheap, so I went that direction.
EV batteries do a great job, but everybody and their cousin are looking for them, so the price isn't that great when used, and new will just bust the budget and hurt your feelings.

See your PM.


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## Steve_S (Feb 25, 2015)

I've seriously digging into this issue and made some very interesting discoveries indeed. I have access to Tesla P95 & Model S packs which range from 1300-1500 CAD 24V 5Kwh (pending on versions, can vary). An external BMS is fairly cheap now days as in < $150 for a decent one with Modbus and/or canbus and some even have Bluetooth for monitoring too. I figured on paralleling 2 of these as option one. I'd consider Tesla, Volt packs but NOT anything from toyota (prius) but Tesla's, even the 18650 originals would be better IMO, as the 21700 cell packs are still quite premium.

As for LifePO4... wow that changed a LOT in 4 years ! There are Battleborn, SimpliPhi and many others with BMS built in as "drop in replacements" but these are usually 12V and max at 100Ahr, and around $1000 USD per unit. When you crunch the numbers though... ouch ! I started looking at CALB Cells (that format anyways) and in reality, these look like another excellent option which is far more affordable. DHGate has several varieties & flavours and many have free shipping to Canada (Albeit, not the speediest S&H) but it still adds up to a lot of savings alone on that. The advantage of that is I could select what Ahr Rating per cell I would like and up to 400Ahr are available, so theoretically I could build a 8s Pack @ 24V 400Ahr but that hits a pricey side. Then of course there is the huge amount of used LifePO4 batteries such as Valence (Hospital equipment) etc BUT for some reason these are not available or shippable to Canada (some kind of silly export restriction) which is truly sad as these are 12V, 100-130 Ahr (pending on version) for < $500 USD each.

The bottom line, I have no issue with building or modifying a pack of batteries and it will come down to Best Bang for Buck as long as it is something that can be added to later (big + fir Lithium) if need be, along with being a simple & comprehensive battery pack.

This fellow created a website & posted many video's on his projects and while he is a young lad, he knows his stuff "fairly" well (although needs to be verified) and there is a wealth of handy info (see his DIY Solar Blueprints section)
https://www.mobile-solarpower.com/tesla-solar-battery-diy1.html


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## JeepHammer (May 12, 2015)

It a no-brainer for me when I can lay hands on LiFePO4 over lead/acid.
The useable charge density being 4x lead/acid, and no toxic/explosive gasses alone trips the 'Easy Button' for me.
Weight isn't an issue for me, but it is for some people, and LiFePO4 checks that box off too.

Common low voltage shutdown inverters won't even come close to damaging a metal battery, while you most certainly can damage lead/acid unless it's adjustable and you are shutting down early to save battery longevity.

I have a couple Tesla S packs around here, between cost/availability and case issues, and finding a source for cased LiFe batteries, I haven't bought another one and probably won't unless I get a screaming good deal on them.
I mostly bought them to learn how to use them, and having done that, I'm not the biggest fan.
Still an order of magnitude better than lead/acid, so if someone wants them I can help connect and get charging set up correctly.

I can't believe people still buy lead/acid in this country for large scale storage anymore, simple demand should tell manufacturers the technology can't be suppressed anymore, it's time to get with the program!


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## Steve_S (Feb 25, 2015)

JeepHammer said:


> It a no-brainer for me when I can lay hands on LiFePO4 over lead/acid.
> ---
> I can't believe people still buy lead/acid in this country for large scale storage anymore, simple demand should tell manufacturers the technology can't be suppressed anymore, it's time to get with the program!


That has been noticed btw. Trojan, Rolls Surette and others are now offering LifePO4 & Li-Ion batteries as well … very slow off the mark IMO. BUT when I bought my FLA's in 2015 @ $340 ea that was a good deal and anything Lithium was NUTZ ! but not so much anymore. Sadly "Politics" is frigging up the whole market and unbalancing costs which is hurting all of us end users….


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## JeepHammer (May 12, 2015)

It's stupid to block import/export of battery/chargers and simply politics at this point.
Everywhere is so far ahead of the US in battery technology it's not funny, and all because the technology has been supressed by big auto manufacturers and fossil fuel companies.
Politicians are cheap & easy to buy...

I had to buy Edison iron batteries from Russia via UK, and that drives the cost up quite a bit!
The best Li batteries are coming out of China & Japan (thanks to Tesla mostly).
The big LiFePO4 batteries made in America come from one US/Canadian military contractor no matter what the name lable says, and we all know how cost efficient the military contractors make things... 

What RE needs is a cost efficient 24 & 48 volt versions of LiFePO4 with enough Amp Hours (say, 5 or 10 kW/H per battery) for common RE storage in blocks of 2 or 4 you are done.
Build the charge controller/BMS into the batter as a module, and again done, doesn't matter the charge source after that, it's plug & play time once it's standardized.

I honestly don't know why we don't have 100-120 volt batteries now.
With panels capable of producing up to 480 volts, it would sure reduce the amount of conductor needed and since the inverter can operate at any designed voltage why are we limited to a base 12 (volt) battery and inverter feed system other than base 12 volts is what lead/acid batteries started with?

If they did so, all that import/export crap wouldn't apply simply because it would be too large/heavy to use as a weapon, or what ever BS the politicians used to block import/export so the fossil fuel and car companies could block RE & EVs...


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## Steve_S (Feb 25, 2015)

Well I am done with Lead once the Rolls are retired to greenhouse duty, along with my Yiyen APC3024 Combi Inverter/Chargher which should be more than enough for that purpose. As my residential inverter/charger is a Samlex 4024, I'm staying on the 24VDC path and that's fine as I do not have any massive loads to deal with as such. I have a while to make a decision so I'm not in panic mode , just in plotting mode as it were.


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## JeepHammer (May 12, 2015)

I bumped up to 48 volts simply because of my demand, the bigger inverters are more efficient at 48 volts. 

I'm kind of locked into current equipment since I have backups for everything, but if I were building from scratch, it would be micro-inverters, drive AC voltage up to about 440/480 volts and use the appropriate inverter that charged batteries and output in common 220 vac for use.

Solves the ling runs of wiring issues or putting batteries/inverter right under the panels, solves the one panel fail crippling the string problems, solves a bunch of problems...
The first one I laid hands on was last summer and at first it confused me, but with peak output of about 460 vac, we are talking 6 ga or 8 ga wire, long runs aren't an issue for AC, the inverters are same price, the inverters are more efficient and much larger capacity for the same price as DC inverters.


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## Steve_S (Feb 25, 2015)

I do not have anything 240VAC only 120VAC here. My Heaviest load is my water pump, a Grundfos SQ5 120V Soft Start which maxes @1000 W when it hits 45psi pressure.


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## Steve_S (Feb 25, 2015)

The TRIGGER has been Pulled !
I just purchased a ShunBin 24VDC / 400AH LifePO4 Battery Pack with internal BMS. The can be connected in Series / Parallel to make even bigger battery banks. They have smaller and larger packs and will customize to suit as needed.
Here is the Amazon USA link : https://www.amazon.com/Lifepo4-Lith...ents=p_4:SHUNBIN&s=merchant-items&sr=1-9&th=1

On another forum I belong to, which is far more techie than here, a few of the guys have them, tore them apart, photo's / video's it all and they even serious beat (read abused) them to push the limits and no issues. I thoroughly checked the company oiut, it's standings and what products they are authorized resellers & manufacturwers for and all good. I asked a coupel of questions on Amazon of the vendor and they responded in 5 Minutes and were very helpful & informative. They are also an authorized VAR / Reseller for Maxwell Super Capacitors.

I pondered & researched many options and even found astounding deals (Canadian Dollars! 25% exchange rate) on Tesla Model S Packs ($1200 a pop) and GM Volt Packs 6S modules for $300 and several other options from building my own packs etc... and Bang for Buck in the end, this is the best solution while applying the KISS rule and allowing for future enhancement with little issue.

Hopefully, this helps others on the quest for Energy Independence & Freedom.
Steve


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## JeepHammer (May 12, 2015)

If you would, let me know how it tests out when you get it up and running?

If they have direct access to Maxwell then it's probably the same cells Tesla uses from that giga-factory over there. 
That free economic zone China has is pretty interesting, completely different economic model that what we are used to...


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## Steve_S (Feb 25, 2015)

It's in Alaska on it's way here and already cleared customs etc... We (another forum) have a running detailed thread on this with tear downs and evals going on. BTW: These are NOT Tesla Cells, they do not have a Battery Factory n China as yet (under construction Phase-2). These are I believe Lischen Cells which have a good rep for cells. The BMS is possibly a bit dubious but we will know quite soon. I wanted one with RS485 Modbus access so I may change it anyways just because I want to know every detail of what my hardware is doing, but that's me.

There are some incredible deals to be had and sadly, if I didn't have the issues of shipping to Canada, I would have bought some packs out of the US. It would have effectively cost me double and that is just not an option.


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## JeepHammer (May 12, 2015)

I've seen that BMS on Amazon, Alibaba, eBay, YouTube or somewhere like that before...
I can't remember where I saw it, but someone was building their version of a power wall and used the same thing, gave specs & source.
I'll keep an eye out when I'm surfing and will let you know if I see it again.

*IF* I remember the build correctly, the guy was changing his over to something connected so he could monitor the charging...
If I see it again I'll link it to you.


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## Steve_S (Feb 25, 2015)

A LOT of companies make BMS' which is an essential / critical requirement for LifePO or Lithium Variants (proper BMS for each type). I'm leaning towards these TinyBMS: https://www.energusps.com/shop/product/tiny-bms-s516-150a-750a-36?category=4 as they have all the right goodies, reputation & quality... Another good brand at a lower price and slightly less features is DALY https://dalyelec.en.made-in-china.c...ery-60A-Continuous-with-Balance-Function.html

BTW: Either of these brands can be retrofitted into many systems with a bit of smart & cautious DIY.


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