Author Topic: 48V battery bank options?  (Read 271 times)

sidpost

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48V battery bank options?
« on: March 18, 2021, 01:15:45 PM »
I see ForkLift battery recommendations here and other places but, I must be missing something as I just don't see them being matched to solar PV systems very well.  They also seem to be excessively heavy and relatively expensive.  Are they a more reasonable battery option than they initially seem to me?


Something like a US Battery L16HC initially appears to be ~$350 (waiting for a hard quote so TBD) per battery with 420A/Hr in it.  Perhaps my battery pricing is off and the ForkLift batteries are more cost-competitive.  In terms of maintaining them, the L16HC batteries seem to be a lot more 'user-friendly' and Solar PV friendly.


At what point does a Generac or Tesla 'Power Wall' make financial sense over the classic flooded battery options?  And yes, lower 'reserve' needs make L16's an obvious choice but, when you start looking at a double string of L16's, the Power Walls seem to become more financially viable.


In my case, I have multiple projects in motion so, while I could use a single bank of L16's today, in the next year I think would have to at least double that.  Do I add a second L16 bank then or would a Power Wall fall in price enough to be a viable option even though the capacity then would probably be pretty far above my actual needs?


For a little background, I live in a relatively rural area with frequent power outages for brief periods.  My domestic needs are mainly protecting freezers and fridges so I don't lose my groceries and power for my water chiller so I don't lose my fish (not an aquarium but, a larger system with 12-foot diameter pools).


TIA,
Sid

boB

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Re: 48V battery bank options?
« Reply #1 on: March 18, 2021, 01:52:30 PM »

Hi Sid !  Welcome to our little (but powerful !)  corner of the internet.

I won't say a lot as there are others here that actually live the off-grid life but one thing I know about lead-acid batteries is that the heavier, the better.  I will never forget that.   Forklift  and golf cart batteries are good because for one, they ARE heavy but mainly, they are meant to be charged and discharged repeatedly and need to be reliable especially for forklifts.

As for the Tesla Powerwall at least, did you know that Tesla has recently decided to NOT sell without their solar panels ?

I just learned that yesterday.

Okay, now the smart people can comment.

Glad to hear from you !

K7IQ

sidpost

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Re: 48V battery bank options?
« Reply #2 on: March 18, 2021, 05:13:15 PM »
That Tesla change is news to me!


It makes sense though because Panasonic apparently has stopped producing solar panels and has sold or leased all of its related facilities.  I'm guessing the Tesla/Solar City and Panasonic relationship didn't work out and Panasonic cut its losses.

boB

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Re: 48V battery bank options?
« Reply #3 on: March 18, 2021, 06:35:13 PM »

Yeah, I'm not sure.   BUT I know that Tesla is the big word nowadays so I don't think Tesla had anything to lose by stipulating this.

K7IQ

ClassicCrazy

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Re: 48V battery bank options?
« Reply #4 on: March 18, 2021, 11:17:58 PM »
Sid ,
Forklift batteries have a lot of lead in them and are made to take a lot of abuse.
But for best life of any lead acid battery you don't want to take more than 20% out of them if cycling often.
Any flooded lead acid battery takes regular maintenance to make sure you don't ruin them so you need to give them water, make sure they are equalized, make sure they get enough charge in float so they don't stratify , etc.  It isn't good to mix lead acid over the years - better to keep them all the same age. Also not so good to have lots of series parrallel strings - that is why high capacity forklift batteries are a good choice if larger amp hour capacity is needed. All the cells are in series.
There are lots of other Lithium options than Tesla power walls .
Lithium is less expensive these days than lead acid . Steve was talking about some lithium types in a recent thread on the forums here .
Basically you have the lithium cells , and then you have a BMS to keep the cells happy and not getting destroyed by over volting ,  under volting,  imbalances, etc.

Larry


system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

Weldman

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Re: 48V battery bank options?
« Reply #5 on: March 18, 2021, 11:58:29 PM »
I'm going to forklift battery my GC batteries took more abuse than usual in western Washington state and killed them early. Didn't live there just was there for extended time.
This is where I am buying from when I get the funds https://gb-battery.com/products/ols/products

sidpost

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Re: 48V battery bank options?
« Reply #6 on: March 19, 2021, 11:19:20 AM »
Thanks everyone!  The ForkLift battery research I have done so far was mixed in terms of the good versus bad.

The negatives I read mainly centered around relatively small acid capacities relative to the plate sizes and weight.  There have also been some negative comments about the internal construction of the cells themselves. 

I know from personal experience in my cars and pickups, that the vibration from rough roads was the main killer in my vehicle batteries.  I still remember the weird looks I got in the Caterpillar parking lot in Tucson, Az when I popped the hood of my Grand Marquis and pulled the battery while wearing Dockers and a Polo shirt during my "lunch hour".  I even had a couple of mine repair guys pull up and tell me it wasn't possible to use a Caterpillar brand battery and, the parts counter guy said the same thing.  The road grader battery I installed worked WONDERFULLY!  It also lasted until that car was totaled.  Spending a little more upfront on batteries does have a good pay-off in the long run!

In terms of maintaining them, EQ, water, etc. are all within reasonable routine maintenance for me.  YMMV

bee88man

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Re: 48V battery bank options?
« Reply #7 on: March 21, 2021, 10:05:19 AM »
Nothing chinzy about lead in a fork lift battery. Fork lift batteries are abused like no other lead acid battery.

And all the series top side conections are non-mechnical, being fused lead...terminal integrity is never a issue.
 
Forget these batteries if stairs are to be used to access location though.

A over head house beam and a pallet jack in a daylight basement or like will make for handy items.

ClassicCrazy

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Re: 48V battery bank options?
« Reply #8 on: March 21, 2021, 01:25:30 PM »
Nothing chinzy about lead in a fork lift battery. Fork lift batteries are abused like no other lead acid battery.

And all the series top side conections are non-mechnical, being fused lead...terminal integrity is never a issue.
 
Forget these batteries if stairs are to be used to access location though.

A over head house beam and a pallet jack in a daylight basement or like will make for handy items.

My friends got an East Penn Deka forklift battery that had studs on top of the cells so you could put a strap on them and pull them out of metal case to move them one at a time. Then you used buss bars on the studs to interconnect them in the case.

Larry
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

mike90045

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Re: 48V battery bank options?
« Reply #9 on: April 11, 2021, 08:31:30 PM »
The only drawback w/forklift battery packs, is their chemistery, they are not as efficient, and consume more water, but who cares, you charge at night, and the water truck fills them in the morning !!
  But off grid, it may matter more.   The HUP brand is also a beefy  lead battery, in 2V cells. but a bit more optimized for solar.

I'm running NiFe, and always watering them !
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

qrper

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Re: 48V battery bank options?
« Reply #10 on: April 12, 2021, 07:53:32 PM »
Lead-acid fork lift batteries are beasts!

They are designed to be abused, and when they live in a solar/off gird application, they can last for decades. And as the name implies, they are used to operate fork lift and transfer carts. They are discharged at a 8 hr rate (normal L-16 is rated at a 20 hr rate)
after the shift, they are charged at high current. Typically 100+ amps at initial charge. We would charge our transfer cart batteries in the mill at 230A at the end of the shift. We used a motor generator set for those batteries.

A few points of interest....

the specific gravity of a fork lift battery is higher than a L16 or golf cart battery. The fully charged SP is 1.300 instead of the 1.275 SP used in a L16 type battery.
There is no problem with 50% depth of discharge, even lower with decreased service life, but at 50% depth, you can still expect decades of use.

They do require a bit more water,

And!!
You need a fork lift to move one. :)

The secret for getting the most out of one is keeping it fully charged and floating. That's seem to be a problem with some off grid systems because there isn't current (PV sized too small) from the PV array to get 'em charged! Nothing kills a LA battery quicker than letting it set in a half discharged state.

Because there may be gallons of electrolytic in cells, you'll need to make sure you can equalize the cells at least once a month.

A new fork lift battery can be quite expensive. I'd poked around looking at used/refurbished from a battery dealer. I wouldn't get one from a friend of a friend who knows this guy type of deal.
When I worked for Republic Steel, you couldn't pay me enough $$$ to take of of their used fork lift batteries! Maintenance on those was like problem 9,843 on the list of things to do. They got looked at when the transfer carts stopped. If possible find out what the history of the battery was. Was it a lease return or did it set for a year in a defunct warehouse?

The biggest issue is their bulk and weight. Unless you have something to move them, putting them in place can be an issue. Best bet for 48 V batteries is to use two 24 V batteries in series. A high capacity 48 V fork lift battery can easily weigh 3000lbs and more.

Even with the price of Lithium ion batteries coming down, it's hard to beat the old school lead acid batteries in a stationary setup.

mike wb8vge
System one: 7kWp w/ Trina 250 W panels @90 Vdc. Classic 150 to 16-6 V U.S batteries. Trace 5548 sine wave inverter.
System two: 6kWp grid tie with solaredge inverter.
System three: Midnite Brat, two 120 W Astropower modules, 100 Ah battery. Runs the LED streetlight in the back yard.

ClassicCrazy

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Re: 48V battery bank options?
« Reply #11 on: April 12, 2021, 09:26:19 PM »
Mike,
Keep in mind that even though you can still get a lot of power out of an older lead acid battery - the self discharge rate starts increasing with age. So it is kind of like having a bucket with some holes. You need to put a lot more power in them when they are older cause more and more is leaking out ( self discharge).
I know someone who had some old telephone company batteries and he liked them because they would run big loads on an inverter. But it was hard to explain that he was dumping so much power into them every day that got lost. They were just sort of like a big capacitor.

Larry
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

qrper

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Re: 48V battery bank options?
« Reply #12 on: April 13, 2021, 10:12:58 AM »
Mike,
Keep in mind that even though you can still get a lot of power out of an older lead acid battery - the self discharge rate starts increasing with age. So it is kind of like having a bucket with some holes. You need to put a lot more power in them when they are older cause more and more is leaking out ( self discharge).
I know someone who had some old telephone company batteries and he liked them because they would run big loads on an inverter. But it was hard to explain that he was dumping so much power into them every day that got lost. They were just sort of like a big capacitor.

Larry

Larry,

You're absolutely correct.

That also explains why you are constantly adding water to the batteries, and why most PV systems can't keep up, and therefore the battery starts to sulfate.

That's why if one is interested, they should buy new or refurbished from a battery shop.
I haven't looked a new forklift batteries for a while, but if memory serves me, a 24 V 850amp/hr battery was between $4500 and $6000. Price varies with manufacturer and of course capacity.

That's why I think a refurbished one would be the best deal provided you define 'refurbished.'  A can of spray paint and new decals? There is a large battery supplier just north of me. They advertise rebuilt batteries. Cells checked, bad ones replaced, new acid, charged/discharged and load tested to 80% of capacity.
Love to have a few... if I had a power house to keep them in... They will deliver to me but what am I going to do with a 4500 lb battery sitting on my driveway?

At $9K for a 48V 850amp/hr lead acid battery on the low end, is pushing up against lithium chemistry.

As much as I love the old school lead acid batteries, I can see the light at the end of the tunnel that the price point of Lithium will soon knock out lead acid in stationary power. The Tesla powerwall has their toes in the door.

mike, wb8vge
System one: 7kWp w/ Trina 250 W panels @90 Vdc. Classic 150 to 16-6 V U.S batteries. Trace 5548 sine wave inverter.
System two: 6kWp grid tie with solaredge inverter.
System three: Midnite Brat, two 120 W Astropower modules, 100 Ah battery. Runs the LED streetlight in the back yard.

sidpost

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Re: 48V battery bank options?
« Reply #13 on: April 13, 2021, 10:20:05 AM »
With all this talk about FORKLIFT batteries, I'm seriously thinking modern Lithium options are financially viable and a whole lot easier to work with.  Sure, you need a Battery Management System to care for them properly but, you also don't need a forklift to move them!  And, $5K~$10K will buy a lot of Lithium capacity!

qrper

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Re: 48V battery bank options?
« Reply #14 on: April 13, 2021, 11:25:33 AM »
With all this talk about FORKLIFT batteries, I'm seriously thinking modern Lithium options are financially viable and a whole lot easier to work with.  Sure, you need a Battery Management System to care for them properly but, you also don't need a forklift to move them!  And, $5K~$10K will buy a lot of Lithium capacity!

You will need to do your homework.

My current lead-acid battery bank has storage of a tad over 42Kwh, of which, 50%, I can draw down without damage to my batteries, that's gives me 21Kwh of capacity.

Now, before the fanboys of Lithium batteries jump me, I know, I know, I know you can discharge them deeper than lead acid batteries.

But if I want 21Kwh of storage using Lithium chemistry.... well a BattleBorn 12 V lithium battery @100 Ahr is just short of $1k. So, I'd need four in series to get 48V.
To get to my 21Kwh storage, I'd need between 4 and 5 strings of four batteries. AT $4k per series string, times four would be $16K, and $20K for five strings in parallel.

Granted, there are cheaper/larger lithium batteries on the market now, I used BattleBorn because the guy I purchased my batteries from was pushing them on me.
While the lithium will last longer in the long term, we live in the now.
I spent almost $5K on the lead acid for 21Kwh storage. The lithium could have cost me $20K.
Now, that's been two years ago and I'm sure the price for lithium batteries has come down a bit.
While you may not need as much storage as I have, and that will certainly adjust the price downward.

At the time, my electric bill was about $60-$90 a month. I'll never live long enough to see a return of investment in my system. It is cool though... running the AC in the summer, charging the EV, and all the other loads with a $zero electric bill. The cost of lithium batteries simply wasn't any benefit to me.

Let us know what system you plan on using. I'd sure like to know.



mike, wb8vge
System one: 7kWp w/ Trina 250 W panels @90 Vdc. Classic 150 to 16-6 V U.S batteries. Trace 5548 sine wave inverter.
System two: 6kWp grid tie with solaredge inverter.
System three: Midnite Brat, two 120 W Astropower modules, 100 Ah battery. Runs the LED streetlight in the back yard.