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ooops! too much water loss in my batteries

Discussion in 'Ask All Sailors' started by Mike Meier, Sep 12, 2017. Add this thread to a FAQ

  1. Mike Meier

    Mike Meier

    Joined Feb 11, 2017
    4 posts, 0 likes
    I have Rolls 4000, 375 amp batteries purchased in Oct. 2016 and the Annapolis Sailboat show. This was my second set, the first lasting for 11 years with no problems. With these, I had to put them through several cycles to get them to hold a full charge. Now, though, through my confidence that the hydro-caps would not allow much gassing, I discovered that the water was below the plates in 5 of the 6 cells. My question to the forum, is what should I expect now? I replaced the distilled water and tried to charge them for about three hours. When I stopped it,they were still taking 14.14 volts. Has anyone had an experience with this? Thanks in advance.
    Mike Meier
     


  2. wing15601

    wing15601

    Joined Aug 28, 2015
    83 posts, 8 likes
    Oday 28
    US St Joseph, MI
    Maybe they're being overcharged because of a charger defect.
     


  3. Ken Cross

    Ken Cross

    Joined Oct 24, 2010
    1,404 posts, 139 likes
    Hunter 30
    US Everett, WA
    Remove one or more and have it checked for capacity. Or buy the equipment and do it yourself. Overcharging does sound likely.
    Ken
     


  4. jviss

    jviss

    Joined Feb 5, 2004
    2,000 posts, 122 likes
    Tartan 3800
    US Westborough Westport, MA
    I don't know what damage may have been done, but let's assume not so much. On the charging side, I assume that at 14.14V you were either still in bulk mode, not having reach acceptance, or you were at acceptance, but it's set too low. Do you know what mode? How much current at that point? It's not inconceivable that a 750AH bank would still be in bulk charging mode after 3 hours. A lot depends on your charging source. More details are needed. Do you have a hydrometer?
     


  5. Benny17441

    Benny17441

    Joined May 24, 2004
    5,185 posts, 254 likes
    CC 30
    US South Florida
    I suspect one of the batteries is not accepting charge, the one paired with it (2 6V) will have drained down too. What is the manufacturing date for those batteries? If they sit on the shelf too long they will sulfate as a result of self discharge. Have them tested. A fact about batteries is that any can last many years or fail in just a few days; that has given rise to the battery warrantee programs. If the vendor was from out of your local area contact the manufacturer to provide local replacements.
     


  6. jviss

    jviss

    Joined Feb 5, 2004
    2,000 posts, 122 likes
    Tartan 3800
    US Westborough Westport, MA
    You probably blow the warranty if there's evidence of 'abuse,' such as low water levels.
     


  7. Benny17441

    Benny17441

    Joined May 24, 2004
    5,185 posts, 254 likes
    CC 30
    US South Florida
    I would not purchase a battery at a retail center with a manufacturing date of over 45 days, preferably 30 days or under.
     


  8. jviss

    jviss

    Joined Feb 5, 2004
    2,000 posts, 122 likes
    Tartan 3800
    US Westborough Westport, MA
    What does that have to do with the water level?
     


  9. Mike Meier

    Mike Meier

    Joined Feb 11, 2017
    4 posts, 0 likes
    Thank you all very much for your suggestions. I had not considered the possibility of over charging. The xantrex 40 amp charger is only three years old and the boat's charging system is controlled by an Ample power alternator and three stage regulator. I have never experienced trouble with this system. I took the specific gravity readings and four of the six cells were showing strong readings. Two of them, next to each other, were not and could not be nudged beyond the "needs charging" section, the numbers being well below the 1.275. So, I suspect, as of now, that Benny is on to something in that one cell is damaged and is draining the other. These batteries were purchased last October and installed in November. I have had to put them through several cycles as the tech folks at Rolls thought that they had been sitting and ignored. This is upsetting, because the last ones gave me no problem. I will probably replace the suspected cells, and, yes, do a load test, and see. In the mean time, thanks again. Mike Meier
     


  10. jviss

    jviss

    Joined Feb 5, 2004
    2,000 posts, 122 likes
    Tartan 3800
    US Westborough Westport, MA
    I'm not familiar with the Rolls batteries. Are you saying you can replace individual cells?

    Is yours the "12 EHG 375P?"
     


  11. Mike Meier

    Mike Meier

    Joined Feb 11, 2017
    4 posts, 0 likes
    jviss, yes, they are six 2.7(+ or-) volts wired in series with thick plates. Together, the batteries weight about 250 lbs. I like them, and I am shocked that I am having this trouble with them. The Canadian product is manufactured by Surrette batteries.
     


  12. jviss

    jviss

    Joined Feb 5, 2004
    2,000 posts, 122 likes
    Tartan 3800
    US Westborough Westport, MA
    Thanks. But, that would be a 16V battery! The nominal voltage of a lead-acid cell is 2V, maybe 2.1V resting voltage, fully charged.

    I like the idea that you can replace individual cells, but I'm sorry for you that it's necessary!

    I imagine these batteries are quite expensive.
     


  13. jviss

    jviss

    Joined Feb 5, 2004
    2,000 posts, 122 likes
    Tartan 3800
    US Westborough Westport, MA
    So, I noticed you are new here. Welcome. I was wondering what kind of boat, and what engine, particularly around charging this thing when it's low. I assume it can put an enormous load on an alternator, and would demand full alternator output for quite a while. What kind of belt and bracket setup do you have for the alternator, if you don't mind my asking?
     


  14. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,376 posts, 329 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME

    • How were these batteries commissioned?
    • Were the cells confirmed to all be at the identical SOC before wiring them in series?
    • What is your charge current as a % of Ah capacity?
    • What is your absorption charge voltage?
    • What is your float voltage?
    • What is your absorption duration?
    • Are you using temp compensated charge sources?
    Rolls batteries in a PSOC application can be charged as high as 15.0V however they will consume more water at these voltages and if any cell imbalances are present some cells will be getting over-charged while others are getting under-charged.

    If the cells were not properly commissioned it is very possible that one or more cells are being under charged/less water use while the others are being fed considerably higher voltages and consuming more water. Cell imbalances are a very common problem in series strings, especially in PSOC use with infrequent EQ's.. For example:

    Resting Voltage - Total Bank Voltage Measures 12.56V
    Cell #1 2.13V
    Cell #2 2.09V
    Cell #3 2.12V
    Cell #4 1.96V
    Cell #5 2.13V
    Cell #6 2.13V

    Charging Voltage - Charger See's 14.6V
    Cell #1 2.47V @ 12V = 14.82V - High Water Use
    Cell #2 2.43V @ 12V = 14.58V - Minimal Water Use
    Cell #3 2.46V @ 12V = 14.76V - High Water Use
    Cell #4 2.30V @ 12V = 13.80V - Under Charged/Minimal to No Water Use
    Cell #5 2.47V @ 12V = 14.82V - High Water Use
    Cell #6 2.47V @ 12V = 14.82V - High Water Use

    Any time 2V or even 6V batteries, like your L-16's are installed they should ideally be parallel balanced or equalized then checked regularly for cell voltage or SG imbalances. The topic of series string imbalances is finally becoming more recognized, but it has been an issue for a long while. To commission series batteries, via parallel balancing, you would need a charger that can charge at 6V or have a 12V EQ setting... For Rolls batteries I prefer to wire the 2V or 6V cells in parallel then charge at 2.4V per cell and allow current to decline to about 1% of Ah capacity. I then boost voltage to 2.58V until SG stops rising or all cells read the same SG. They are then un-wired from parallel and allowed to rest for two to three days and SG and open circuit voltages are checked again.

    Unfortunately these commissioning procedures are rarely employed and we see destroyed banks due to cell imbalances, infrequent EQ's and too high a charge current. Rolls does not want to see a charge current of more than 10% of Ah capacity or .1C, though they now, as of 2016, allow up to .2C, where other flooded brands can be charged as hard as 25% - 30% of Ah capacity.
     


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  15. jviss

    jviss

    Joined Feb 5, 2004
    2,000 posts, 122 likes
    Tartan 3800
    US Westborough Westport, MA
    MaineSail, just, wow. Who knew? I don't think Rolls' manual says this.
     


  16. JamesG161

    JamesG161

    Joined Feb 14, 2014
    1,843 posts, 264 likes
    Hunter 430
    US Waveland, MS
    I found that my battery charger, when left on while on shore power, has a very low Maintenance Charge. That "trickle" continues to react and make H2O go to H2.

    I now turn the charger OFF for the most part, in berth.

    When I go to the boat to check up, charger ON. When leaving again. Charger OFF.

    Mine are Wet Cells.
    Jim...
     


  17. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,376 posts, 329 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME

    Not just Rolls ignores the discussions around good commissioning practices but they also ignore series string imbalances almost entirely. I have been harping on proper commissioning, & series imbalances for years, and it has only been in the last two years that actual manufactures, such as Victron, are finally stepping up to the plate offering series string balancing devices. It's not something you can ignore after commissioning though. With series strings EQing is critical to maintain balanced cells. The problem is not just one of initial SOC imbalance but varying cell capacities and varying Coulombic efficiencies too. PSOC operation only exacerbates the problem and makes it worse. Sadly most chargers out there really stink and can't even EQ or charge correctly.
     


  18. jviss

    jviss

    Joined Feb 5, 2004
    2,000 posts, 122 likes
    Tartan 3800
    US Westborough Westport, MA
    MaineSail decoder ring:
    SOC: State Of Charge
    PSOC: Partial State Of Charge
    SG: Specific Gravity
    EQ: Equalize, Equalization
    Ah: Ampere-hour
     


  19. Maine Sail

    Maine Sail Moderator

    Joined Feb 6, 1998
    10,376 posts, 329 likes
    Canadian Sailcraft 36T
    US Casco Bay, ME

    Bingo!!
     


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  20. Mike Meier

    Mike Meier

    Joined Feb 11, 2017
    4 posts, 0 likes
    As usual, Maine Sail blows me out of the water!!!! As one who consults his web site often, this one is amazing. I didn't realize some of this and I don't consider myself ignorant on somethings "battery" Thanks very much for this, and I doubt that my zantrex charger would do the complex maneuver that Maine Sail suggests. Still, it is something that will stick with me for a while. Maine Sail has correctly analysed the root of the problem I am having by questioning the commissioning procedures of the batteries. The answer is I don't know and the dealer from whom I bought these remains aloof and as helpful as a worn out battery. I will continue to measure thee SOC and SG and see what happens. If I have to junk the batteries, I think I will change brands. I never thought I would say that. Many thanks.
    To jviss, yes I am new to the board because I spent most of my time on the old CSBB and moved with them to here. The boat is a 1982 Pearson cutter with a Universal 5444 diesel. 1985 hours. Twelve years ago, I rewired her and replace the standard alternator with an Ample Power small case, 100 amp unit. The v belt is 1/2 inch. Even though you can sense when the alternator engages (when oil pressure reaches the where it should) I have not noticed nor have I seen excessive ware on the belt and no wear on the pullies. For regulation, the ample power, Next Step three stage one continues to work after all this time. Ample power has changed somewhat, for example, I don't think they make the EMON, or monitor anymore. Thanks again, Mike Meier---I will add more.

    Thanks again, M
     



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