A tech talk with a US battery guy

Started by qrper, August 15, 2019, 01:04:29 PM

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qrper

Gang...

I dropped a un-holy amount of money of these new L16HC US Batteries. I scoured the 'net looking for information on the proper way to charge them. Of course US Battery has some guide lines, but frankly, they don't set well with a solar electric charger.

So, I spent 45 minute on the phone with a battery tech from the factory. The factory guide lines (on their website) for the 3 stage charger isn't quite right for solar.
Here, in a nut shell, is what he told me.

Bulk charge to 2.45 V per cell. For my 48 V nominal battery bank that's 58.8 V
Then hold that voltage (Absorb) until the current drops to 3% of the amp/hr capacity of the battery.
To make this simple I'll only use one of the strings of batteries. So 442 amp/hrs at 3% is a hair over 13 A.

I explained that I can't hold the current steady because it is constantly changing do to clouds, dust, birds, etc, and the controller only allows me to adjust the voltage and time.

He said that I should then hold the absorb voltage at 2.45 V per cell for 2 to 3 hours.

US Battery doesn't recognize a 'float voltage' as a stage. However he said I should set, if possible, a float voltage of 2.1V per cell (52.1V)

A new LC16HC will have a specific gravity of at least 1.270. After the first dozen cycles, that should go to 1.275 to 1.280. Equalize the battery at least once per month to 61.2 V (2.55 V per cell) for at least 1 hour. As the battery ages, the equalization time will need to be extended to as long as 3 hours.

I hope this helps with the US Battery users.

mike
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.

Vic

Quote from: qrper on August 15, 2019, 01:04:29 PM
Gang...

   ...   I explained that I can't hold the current steady because it is constantly changing do to clouds, dust, birds, etc, and the controller only allows me to adjust the voltage and time.

He said that I should then hold the absorb voltage at 2.45 V per cell for 2 to 3 hours.

I hope this helps with the US Battery users.
mike

Hi Mike,  Thanks for the US B Solar charging info.

Will add one point,  or so;
The Ending Amps (current)  is controlled by the Acceptance of the battery.   As long as there is sufficient Solar input to maintain the compensated Absorb voltage,  the EA value is primarily due to battery Acceptance (there will be some current Jitter,  which can have a considerable effect on when the Classic will end Absorb).

For our old-ish battery banks here,   the ideal EA value changes,   depending upon DOD of the battery in the previous discharge,   and also (apparently),    the charge Rate at which the battery was recharged (or,  probably the average recharge Rate).

Perhaps,   a Rate-Of-Change in EA  could be a more predictable method for using EA to end Absorb   ...(?).

FWIW,   probably trying to put too-fine a point on this pin.   73  Thanks,   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

boB

As far as Absorb time stopping because of clouds, etc, that is typically OK...

Over the course of the day, it should accumulate those hours of Absorb even though it took longer than those hours to accumulate the time at Absorb.

The bit of jitter while being close to the 3 amp ending specification can be a problem.

I thought I made a software change to help that ?  Vic... Can you remind me if I did that ?  All it would have done would be to require a certain amount of time (seconds) before the ending amps timer was reset due to the sudden spike of current over the ending amps setting.

I seem to remember thinking about that at least...   :)

boB
K7IQ 🌛  He/She/Me

Vic

Quote from: boB on August 15, 2019, 02:41:51 PM

   ...   I thought I made a software change to help that ?  Vic... Can you remind me if I did that ?  All it would have done would be to require a certain amount of time (seconds) before the ending amps timer was reset due to the sudden spike of current over the ending amps setting.

I seem to remember thinking about that at least...   :)

boB

Hi boB,

You DID  change the Classic FW to reduce the Jitter,  just after the WBjr began shipping.   It  was a large help.

AND,  you had wondered out-loud in a Thread,   about 18 months ago,   about changing the EA function,   as it approaches the set EA,  BUT,  have read nothing of any such change in the Classic FW.

On the systems here,  the EA value rattles around,   and,   as one is watching and waiting for EA to end,   on the MNGP,  we see about 0.8 Amps of total variation in a period of 30 seconds,   or so  ...   this is with a constant load on the inverters.  As  we  are waiting for the EA value to stop its descent.  The Jitter can make a 30,  or so minute difference in the Absorb duration.

Of course,   there is an additional factor that comes into play when nearing the set EA value.  This is voltage drop in the cable and breaker that connects the Classic to the battery.   With opportunity loads,  such as A/Cs  that cycle,   our systems can see about 1 Amp of EA current twix one A/C running and not.   YES,   this is too much drop in that connection.

Some of the above apparent voltage drop,  is due to noise from the venerable SW+ inverters,   and some appears to be from the Classic,  itself,   and there  bound to be the jitter caused from the Classic maintain its Absorb voltage.   Had wondered if running STC String Vmps of 106 V,  increases this Classic Vout jitter,   vs a bit more reasonable Vin to the Classic   --   85-ish volts would seem ideal for most FLA-based systems   ...

A communication box that could report Sense Lead-measured actual battery voltage should nearly eliminate Absorb voltage variation from voltage drop in the Classic battery connection.    And so on.

Some day I will probably try to shut off the A/Cs when the set EA is approached.  This would help reduce the cycling load variations in measured EA.

BTW,   the single Classic on this system  --  S/N 3677,  went into service in about 2011 (and was a pristine Refurb,  at that).   All of the SW+ inverters are in their 14th year of service.   Had wondered,  it the capacitors on the Vbattery inputs have gotten worked-to-death,  and perhaps need replacing.

The above is not a huge deal. The Classic (and KID,  too), are by far the best CCs available.  The WBjr has been a very useful and inexpensive addition to all of our systems   ...   we all just always want MONE !!

Had wondered about adding back-to-back SuperCaps across the Shunt sense leads to try to calm some jitter,   realizing that a 500 A Shunt is very low Z.

Had looked for boB's  thoughts about reducing EA end uncertainty,   but could not find it,  yet.

Thanks boB,   for all that you do for us,   and being present on the Forum.   73,  Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

qrper



   ...  I thought I made a software change to help that ?  Vic... Can you remind me if I did that ?  All it would have done would be to require a certain amount of time (seconds) before the ending amps timer was reset due to the sudden spike of current over the ending amps setting.

I seem to remember thinking about that at least...   :)

boB



Ah... people that code are on a different plain. I'm still trying to get the silly LED to blink  on my ardunio.

The conversation with the guy at US battery was somewhat unusual. I would have thought that a company after the AE business would be a bit more on top of photovoltaic installations. Perhaps they are, perhaps this tech wasn't quite up to speed.

I told him I'd figure I'd use the Trojan L16 charging specs and he told me that wasn't a good idea as (surprise!) their, US Battery, paste is much better than the other guys. Therefore the charging curves are different.

I talked to a tech person at Midnite solar about the end of charge amps and he suggested 8.4 A. The batteries seem to be happy, I did my first EQ on them yesterday, and had a nice boil of the electrolyte.

Mike
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.

Vic

Hi Mike,

I believe that the US B-suggested 3% of C for the EA value is too high for daily cyclic use,  unless the batteries are taken to an SOC around 50%.  This is generally considered to be too low for long battery life.   So,  do agree with the MN Tech,   about 1% of C,  is a good place to start,  especially for a very young battery bank.   Just watch the WBjr battery charge current.  When it really does stop decreasing,   this is about the right point as the EA setpoint.   Of course,   use your good Hydrometer (Refractometer),   to confirm.

Standard charging recommendations from most battery manufacturers are for Grid-charged systems,   and assume a Constant Current Bulk,   which Solar-charged systems would have trouble doing (in any reasonable amount of time).

Some of the battery specs,   like FLA battery efficiencies,   appear to be (roughly)  valid only when the battery is completely discharged  --  0% SOC,   and should be lower for our off-grid systems that see an average DOD of about 80%,  or so ...

Believe that for most battery vendors,   off-grid,  Solar-charged systems are still a fairly small part of their sales.   IMO,  L-16 HC batteries are often considered to have a target market for "floor scrubbers".   Perhaps also finding a large market,  powering in-store carts for disabled shoppers,   etc.    Assume that  off-grid is not a large segment,   yet,   ...   who knows ...  But  L-16 HCs  are true Deep Cycle batteries.

FWIW,   all,   IMO,   73   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

qrper

Hi, Vic,

The "L" in the L16 is for the Lincoln model 16 floor scrubber.

It appears that every battery company in the country sells a 'L16' of some sort. I know that Trojan was really pushing their products for AE. The tech I talked to at US battery mentioned that Trojan was purchased by an investment group. That's bad news... been there and got the T-shirt. Apparently (and I don't know where he's getting his info) the group hasn't found a buyer yet. Buy low, flip it and make some $$$.

Have you had any experience with the large forklift batteries? I've kicked the idea around several times. New is out of the question. Re-conditioned? Boy... when I was a Trojan battery dealer, the owner of the distribution center all told me, "only the rich can afford to buy cheap batteries.'

Mike
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.

boB

Quote from: qrper on August 16, 2019, 11:39:02 AM
Hi, Vic,

The "L" in the L16 is for the Lincoln model 16 floor scrubber.

Mike

I had never heard that before.
K7IQ 🌛  He/She/Me

ClassicCrazy

Quote from: qrper on August 16, 2019, 11:39:02 AM
Hi, Vic,

The "L" in the L16 is for the Lincoln model 16 floor scrubber.

It appears that every battery company in the country sells a 'L16' of some sort. I know that Trojan was really pushing their products for AE. The tech I talked to at US battery mentioned that Trojan was purchased by an investment group. That's bad news... been there and got the T-shirt. Apparently (and I don't know where he's getting his info) the group hasn't found a buyer yet. Buy low, flip it and make some $$$.

Have you had any experience with the large forklift batteries? I've kicked the idea around several times. New is out of the question. Re-conditioned? Boy... when I was a Trojan battery dealer, the owner of the distribution center all told me, "only the rich can afford to buy cheap batteries.'

Mike
Our local battery supplier says the forlift batteries are the best - they are made to be cycled heavily daily and sort of abused so do really well on solar systems. He deals East Penn Deka . I was at his shop once and he was refurbishing battery packs by load testing each cell , the using cells from different packs with the same discharge characteristics. They  had huge load testers there. The difference between some of the forklift packs was that some have all the interconnects welded  on each cell ( at least I mean permanently connected ) . The ones he often gets for people with solar systems the cells have studs so they can be individually lifted out of the metal case for transporting and moving around the pack.  Also he said that the cells that on the forklift packs that usually fail first are the ones in the center where they get hotter and less cooling.

I know a couple people who have these forklift battery packs and they have been happy with them. Like all battery packs they need regular maintenance and a few deeper cycles every so often to keep the electrolyte from stratifying .

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

qrper

Larry,

That's interesting about the center cells going bad from heat.

Before I purchased the US batteries for the installation, I had considered a forklift battery. Issues on how to get it from there to here as well has once I got it, how was I going to move it kept me from pulling the trigger. I thought about getting 12 V batteries (they were lighter ) and putting four in series.
I've seen 12 V @ 250 Ah used forklift batteries for about $900. Two Trojan T125s would be 12 V@240 Ah. Why the difference in price when you're talking apples to apples in Ah capacity. Would the difference in service life be the key?

I worked at Republic Steel and we used large 48 V 2500 Ah batteries in our transfer carts. There were two of them in parallel. A lead-acid battery in those carts had a death sentence!

We'd run'em until someone had to get a forklift and push the dead cart to a charger. You couldn't check water or add water to the cells without removing the top of the cart, a nasty dirty job, so it was rarely done. Those batteries lasted a bit over a  year before they were toast.


mike.
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.

Vic

Hi Mike,  not much time right now,   but,  here is a Thread on another Forum,   regarding REfurb Forklift batts:

http://www.outbackpower.com/forum/viewtopic.php?f=17&t=14158

Had thought about a new FL battery when one of the main banks here goes south  --  they are in their 14th year of service ...

73,  Later,  Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

Vic

Hi Mike,

While  we have had very good luck with Surrette batteries (4KS25P & even S530s)  --  all of these batteries have been in service for more than 13.5 years  --   the replacement cost for a 48 V bank,  is now about $18 K (with shipping and CA Sales TAX [at 9.75%]) per bank.   New forklift batteries seem fairly attractive   ...

But,  of course,   forklift (FL)  batteries are designed for a very different task,   as you know.

For a given AH Capacity they generally have fewer plates in parallel,  per battery,   which can often mean poorer surge current capability,   vs more traditional deep-cycle batteries.

They have higher SG electrolyte (often,  at 1.285,  or higher),   which shortens life,   and would generally necessitate higher charge and EQ voltages,  which can upset some inverters,  especially with cold batteries,  in EQ.

Because Capacity in a small volume is important for FLs,  there usually a small electrolyte Reserve space above the plates,   and,  often less space below the plates for shed plate debris.  This usually equates to more frequent checking/adding water,  in the first case,   and probable shorter battery life in the second,  when compared to premium deep-cycle batteries.

IMO,  why go to the bother of dealing with transporting,  unloading,   and placing  FL batteries that have cells that have often been beaten nearly to death,   and might only survive a few additional years of service for you  ...

If we were to try a FL battery,   would probably do as you noted --  specify four 12 V batteries,   each of which (in our case)  would only be about 1,000 pounds.   And  each 12 V battery would be able to rid itself of internal heat much better than would a 48 V FL battery,  with cells tightly-packed in a steel can.

We are hoping that the existing large banks will go some more years,   before we need to make that decision.

Just opinions,    FWIW,   73  Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

ClassicCrazy

Just to be clear  - the people I know who use fork lift type battery packs got them new. The dealer who reconditioned packs was doing it for forklifts . I wouldn't buy a reconditioned forklift pack.

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

bee88man

As for FL battery having more heat in cente cells issuer, it is a factor of depth and durtion of discharge...for a solar application it may not be the same as in a real fork lift application...think about it....

qrper

Quote from: Vic on August 17, 2019, 07:31:18 PM
Hi Mike,  not much time right now,   but,  here is a Thread on another Forum,   regarding REfurb Forklift batts:

http://www.outbackpower.com/forum/viewtopic.php?f=17&t=14158

Had thought about a new FL battery when one of the main banks here goes south  --  they are in their 14th year of service ...

73,  Later,  Vic

Vic....what are you using for batteries that you got 14 years (and running) The last batch of golf cart batteries lasted 7 years, and I was tickled pink with that amount of time. I hope to get 10 years out of the new US Battery L16HC that I just hooked up.

mike
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.