Battery Issues

Just replaced my old battery bank with six new L-16 trojans last week and I think I have a bad battery.

I am set up as two parallel strings and in one string, one battery's SG has gone to pot. the other is 1.270 and some change. This string will only take 4 amps as measured by my Trimetric. The low battery will hardly bubble the other bubbles pretty vigorously.

The other string will take 70 amps at 14.6 volts and tapers off as the charge comes up. This is starting forma 12.3 volt readng on the string.

I'm charging with a 160 amp alternator and a Balmar ARS-5.

Thoughts, what am I missing?

Thanks

Mike

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Battery Issues

    Use voltage meter to check voltage across each battery and each cable/connection (when under load or charging)...

    The batteries should have balanced voltage (near same) readings across all batteries under all conditions (load/charging/idle).

    Each connection drop (cable end to cable end, cable to battery lug, etc.) should have virtually zero voltage drop (or a few millivolts at most) when charging/discharging (try to make large amperage flows). If you have a bad connection you will see hundreds of millivolts across a bad connection or bad cable.

    Would not be the first time a brand new cable was not properly crimped or connected. :cry:

    Otherwise, are the "dead" battery's cells all reading the same SPG? Or is one cell quite a bit different than the rest?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Battery Issues

    Once again Bill has beaten me to the punch. As a simple experiment, after checking the SG of each cell, check the voltage of each cell. (Many people don't realize that you can check the individual cell voltage by carefully placing the volt meter probes in the electrolite , one in one cell, one in the next).

    I would then mix up the batteries and the cables to see if I could replicate the problem in another configuration. You really want to get the individual batteries charged.

    It is also possible that you do indeed have a bad cell or battery.

    Good luck,

    Icarus
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    Bill

    Thanks for the advice. I'm shutting down for the night and will go at it bright and early tomorrow.

    All cells on one battery are uniformly low SG. The other is maxed out, 1.26 at 45 degrees F.

    Will check, clean, and measure in the A.M.

    Thanks

    Mike.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Battery Issues

    Having one uniformly low battery in a series string sounds strange... Were all of the batteries fully charged (by measuring resting voltage and SPG) before they where connected?

    Was there anything done with the one battery (operated in a different bank, treated differently, etc.) versus all of the other five?

    In any case, you probably need to disconnect and recharge that one battery and see if you can bring it back up.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Battery Issues

    twombo,
    as an addition to what icarus had said about putting the meter leads into the cell, i don't place the original test leads into the cells as i use a piece of copper wire(not flexible) so that i won't ruin my test leads and i'm less likely to get acid on me that way. i use the bare copper hard drawn wire that you're likely to see on the ground wire of a romex run. the stranded wires you'll see like for speakers are not stiff enough to use.
    also note that it is not necessary to put both leads into the acid as one could use say the negative post for the negative lead and measure each cell as you go. this means the voltage you get will be only 1 cell for the one closest to the negative post, but the next cell will show the volage for the 2nd cell and the first cell. the 3rd will show the voltage for the 1st+2nd+3rd cells. simple subtraction will give the individual voltages for each cell.
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    If the "bad" battery is in series with another "good" battery and all the sg readings in the "bad" battery are roughly the same, assuming there are no extra loads on that one battery, then it would sure seem to me that that one battery, all by itself, should be taken out of circuit and given a real good charge to bring it up with the rest. It sounds like it may have been sitting around for a while compared to the rest and perhaps self discharged. That, or someone else had it before you did, ran it down and then returned it :(
    Good luck
    Wayne
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    Now For some data.

    Thoroughly cleaned all cables and battery flagposts before any measurements taken.
    voltage drop is less than 1 mv on all cables at rest. Terminals were disturbed last night so readings were not taken, but there was some crud on them. My bad there!

    String 1:

    Average Voltage drop in cables is 14 mv (plus or minus 3) at charging voltage of 14.6 v, 3.5 amps seen. SG this AM is 1.25 for bat 1 and 1.00 for bat 2, at rest for 7 hours. Temp is 41 F. resting Volatage drop is Less thana milivolt

    String 2:

    Average Voltage drop in cables is 26 mv (plus or minus 5) at charging voltage of 14.6 v, 50 amps seen (tapering to 16 amps in 25 minutes). SG this AM is 1.23 for bat 1 and 1.23 for bat 2, at rest for 7 hours. Tri-metic read 12.6 at 7 A.M. Temp is 41 F.

    12 amps load for 3 hours last night on string 2.

    Am gonna pull string 1, bat 2 and take into town to have charged.

    Thanks

    Mike
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    Oh yeah, Batteries are 10 days old and 600 cumulative amp hours total. I normally get about 1 to 1.1 kw solar production each day. My usual daily load is 50 amp hours. I charge to float on the Balmar if I see 12.4 volts at rest otherwise.

    Mike
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Battery Issues

    Did it ever work correctly? 1.00 sounds like they filled the battery with pure water (no acid).

    Measuring the voltage drops I recommend doing it per cable/connection (including jumper cables--looking for one bad one not carrying its current due to high voltage drop)--Not sure what you told me (sounds like only one drop was measured???)

    You have ~14mV drop at 3.5 amps vs ~26mV drop at 50 amps--so for 14x the current you only have 2x the voltage drop--indicates to me that the 14mV is not measured the way I expected, or that you have much higher resistance in that cable/connection...

    It does not matter now that you have disconnected your string--but next time when you bring the battery back, try disconnecting the "good string" and only connecting the "bad/fixed string"... what I am looking for is something like this. Put a load (or a charge) of high current (50 amps looks good):

    +29 vdc charging
    ....14mv.... 15.5v . 1,000mv .. 12.1v .. 386mv
    +--wire 1--| Batt A |-wire 2-| Batt B |--wire 3--|ground connection


    So, from this example, the 14mV cable is fine, the 15.5 volt battery "A" has high resistance (for some reason--could be fully charged and equalizing or bad cell--check SPG and for bubbling in all cells). The 1,000 mV cable is a big drop (dirty/bad/loose?), The 12.1 volt battery "B" is either fully discharged or has an internal shorted cell (or something). The 386mV drop ground cable has "iffy" voltage drop. Notice that all individual voltage measurements have to add up to the 29 volt input (in this example).

    At 1 volt drop and 50 amps--that is a 50 watt "heating element"... In my old days--I would crank a car with the coil disconnected for about 30 seconds. Then use my hand to find "warm" wires/connections and clean/fix those.

    Hope this is clear...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    Bill

    Gotcha!

    I thought it was working fine. With an hour and a half rest between sundown and my getting home I would see 12.7 to 12.9v on the Tri-metric depending on the collection for the day, and 50 - 70 amp hours of usage I would see 12.4 or 12.5 in the morning before sunrise.

    I'll check as you described and pass the data back.

    My cable measurements were roughly 14mv per cable on string 1 for a total of about 42 mv and about 90 mv total on string 2. I didn't check the actual voltage across the battery terminals. I see the methodology now... I'll do that! A little Ohm and Kirschoff in play here!

    Talked to the battery distributor and the dealer is charging the beast and, hopefully, I'll pick it up tomorrow and reinstall it, do a finish charge taking readings along the way, and then take resting measurements in the AM.

    thanks

    Mike
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Battery Issues

    Mike,

    Sounds like you got what I was trying to say... For one whole battery to go dead in a series string--just sounds like the battery was not "right" in the first place (not fully charged, not properly prep'ed with acid, not built/handled correctly).

    Good Luck!
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Battery Issues

    i was thinking he made a typo on that, but i don't think he got it that a specific gravity of 1 means somebody put water into the battery rather than electrolyte, that is no acid. twombo can you confirm that specific gravity reading?
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: Battery Issues

    Hi Mike,

    Am trying to understand the configuration of your strings.

    You noted that you have replaced your old bank with six L-16's. Looks to be a 12-volt configuration. The L-16's that I have seen are six-volt batteries. SSSOOOOO, did you get 4ea L-16's ?? Do you have three strings ?? Are you using some of the old batteries combined with the new ones ? Or mabe I do not understand how you have paralleled the batteries.

    Bet that I'm missing something(s).

    Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    That SG really gets to me too! The red on the float is submerged below the "acid" level. And why the other battery is at a high state of charge is strange. The battery distributor asked me "are you sure?" The battery in question has an electrolyte level in 2 cells that is about 3/8" low or more. VERY noticably low and they were level when installed.

    Is it possible that it took me ten days to note the discrepancy? I suppose it's possible I've had a dead player all along and given my low consumption it is finally showing through. I distinctly remember the battery lady checked the SG before I loaded the pigs up! I recall seeing 1.270 on each though.

    Logically, I should have installed the batteries and ran them through a charge cycle.

    I DO have four L-16HCs connected as two parallel strings of 2 each. The entire old pack was donated to someone with a desperate need... No mixing of new and old. The cables aren't new but are in very good shape and were carefully constructed from 105 C, 2/0 THHN flexible cable to include pneumatic swedging connections and heat shrink sealed. My buddy checked them with a "Megger" on his test rig. All terminals are the really nice, tin coated copper ones that look like investment cast or forged... not the cheapy ones made of thin wall copper tubing.

    The batteries are connected between negative and positive bus bars made of 1/4" by 1" pure copper and have 105 C, 4/0 THHN leads to the rest of the system.

    I am anxiously awaiting word from the battery shop.

    thank again guys

    Mike
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    Battery shop charged all afternoon and overnight till today at 4 pm and it's dead as can be! 1.0 SG!!!

    Waiting for replacement, hopefully tomorrow from Redding.

    Odd, I've asked that they give a little feedback on the cause if possible, but, I figure fat chance!

    More later!

    Mike
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Battery Issues

    Sounds like the battery either had water (instead of electrolyte) fill or there is an open in the battery somewhere (wonder if they are getting any current and reasonable voltage from the battery during charging)...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Battery Issues

    bill,
    even if the battery would've sat since he had bought it i doubt it would ever run down to pure 1.0sg. batteries are almost always given a bit of extra sulphuric acid to overcome that which may become airborn during years of normal charging too. a bypassing short occurring on that battery (odd to have across all cells) would be like having the battery just sitting there with nothing going into it or out of it. an open cell would stop all of the batteries from getting a charge that are seriesed with the bad one making those batteries have the same sg readings. somebody put water into that battery and not electrolyte imho.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Battery Issues

    At this point, it is all a guess anyway... I was just looking for further information (amperage and voltage under load/charging conditions)... It was strange that one string had 50 amps and the other 3.5 amps when operated in parallel. :confused:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    My bad! The 3.5 and 50 amps were charging in isolation from each other.

    Stopped at the battery place yesterday and the after some 40 hours of charging, the SG was 1.25 but when the load tester was applied, it dropped rapidly while "hot". After 30 minutes it wouldn't even go into the "green" at all.

    Waiting for a replacement!

    I have tracked my usage and charging events on String 2 and will duplicate the last few days usage on String 1 before I marry the bank bank up... probably Christmas day.

    Got a 1 kw of charge off the MX60 yesterday.... String 2 was in float!! 12.6v this AM.

    RE: Neil's last post, The the string mate to the battery in question was indeed still at a high rate of charge after a finish charge was applied Saturday. Sunday seems to be the day something went south, because, Monday, my rate of discharge went up noticeably.

    I can see my Trimetric from my easy chair so I watch it regularly to get a handle for how the system behaves. As John Muir of "Compleat Idiot" fame said "know thine ass, for it bears your"! Learning the difference between concern and over concern is an interesting endeavor.

    It would be nice to be able to expect a decent fault analysis after the dust clears, pinpointing what actually happened, alas, fat chance of that... not over a 300 dollar battery anyway.

    More later

    Mike
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Battery Issues

    an sg of 1.25 rules out my water theory. that's a good one, but as you say, we may never know what really happened.
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues
    niel wrote: »
    an sg of 1.25 rules out my water theory. .

    Unless that is, they dumped the water, put in acid and then tried to charge it. Who knows what went on behind closed doors. The good thing is, a new battery is on the way. That makes it all OK.
    Wayne
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Battery Issues

    that's true wayne. i actually don't know if the battery would be ruined by using straight water and then replacing it all with the acid electrolyte later. i never tried it and never heard of anybody else trying it either. i would suppose that the same individual that may have inadvertently placed the water into the battery may have tried to coverup their error by putting the acid in now.
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues

    All things considered, it is a great learning experience!

    Best part of this, is I have a completely redone power center!! All nice and neatly wired and fused, battery cutoff switches and proud to look at and use. Makes a fella have a little bit more confidence in the system and it was a great learning experience for me and my neighbor Todd who is just getting into the RE lifestyle.

    We built him a temporary DC charger with a Wisconsin Robin and a Balmar ARS-4 and a large frame Prestolite. That gets him away from charging at a gallon per hour to a gallon in three hours. We have a 500 cc twin Yanmar Watercooled prime mover collected from derelict ThermoKing fridge unit to move forward into the future with.

    Got one more Yanmar on the way to build up for the retired/disabled couple up the hill.

    Another Kubota EB300 genny is in the plans for my banjo playing Bluegrass buddy who is building a cabin across the road. He is disabled too.

    Now If I can get retired from my day to day job. I'll have a little time to get something going.. HA HA !!

    The story will continue next week. The new battery is being shipped from San Diego for crying out loud!!!! Next Wed at the earliest.

    I'm good Will go buy a used Country #210 wood stove tomorrow.. yee haw!

    Cheers to you all and a Merry Christmas my friends!!

    Mike
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Battery Issues

    hope your projects all work out for you mike and good luck with the battery.
    have a Merry Christmas and a Happy new Year to you as well.
  • System2
    System2 Posts: 6,290 admin
    Re: Battery Issues
    twombo wrote: »
    Battery shop charged all afternoon and overnight till today at 4 pm and it's dead as can be! 1.0 SG!!!

    Waiting for replacement, hopefully tomorrow from Redding.

    Odd, I've asked that they give a little feedback on the cause if possible, but, I figure fat chance!

    More later!

    Mike

    Oh, I'm soooo envious that you're getting a replacement!

    My installation guy installed my monitor wrong, and my batteries are WAY ruined. They no longer have much capacity... So I have masses of FLOAT electricity every day, now.

    I'll have to replace my batteries... but, not today. :)

    I'm heating with candles at the moment, so obviously I don't have coin for new batteries...