Battery Maintenance

I intend to clean up my battery bank this weekend, but I want to do so safely. Do I need to shut my auto generator function off, shut every thing down and then clean the batteries? Or should I simply disconnect each one one at a time, leaving everything running as I clean post and add water? That shouldn't take but a minute or so for each battery. Also, should I rotate my batteries into a different order? These are exide gc wet cell batteries similar to the trojan t105.
When I finish I would like to perform an equalization on my battery bank. I have an outback mx60, fx3524, and mate. Can someone tell me what buttons to push to do the equalization? Thanks for the help.


  • BB.BB. Super Moderators, Administrators Posts: 33,085 admin
    Re: Battery Maintenance

    The general warnings:

    Batteries generate hydrogen gas during charging... So, you should disconnect one link to each parallel string (if you have any series strings) so that no current is going through the battery connections that you are breaking and making during cleaning (to prevent sparks from lighting off any hydrogen gas in the batteries themselves).

    Also, if you were to have heavy currents flowing (charging or discharging) while making/breaking connections, you could get a good size arc going and/or spot weld the connections together.

    Make sure that there is no possibility for current flow through your batteries while breaking/making connections.

    I like to use a fan and/or open windows/doors in the area and get good airflow across the batteries to make sure that there is no excess hydrogen in the area.

    You should wrap electrical tape around your metal tools, and, if needed, use some sort of mats and/or wood panels on top of other batteries in the area if you could accidentally short them out while working on any particular battery.

    Also remove any jewelry, rings, clips, keys, etc. that can fall and short. And use a full face mask and make sure your glasses (if you where them) don't fall onto the batteries either.

    You should be able to add water at anytime (while charging/discharging/etc.)--just make sure that you only use plastic/glass/rubber/insinuative type containers and funnels--and remove any jewelry before starting.

    Lastly, make sure that you and your work area are in such a condition that if you are surprised by a small explosion or sparks and you were to jump back--that you will be safe and not land in or hit something or somewhere where you would get hurt.

    Regarding the mx60 controller and such, I have been to Outback's website before and found the manuals for their products on-line if you manual is missing.

    Not the battery expert here--but these are the basics I would start with.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: Battery Maintenance

    Trojan's on-line battery maintenance manual includes text- and video-based cleaning instructions. The video uses what appears to be a bank of T-105s as an example, and the implication is to shut everything down, take the entire bank apart, and clean and inspect both the batteries and the cables. Sounds good to me.

    As Bill noted, Outback's user manuals include equalization instructions. Note that the batteries must be fully charged (Bulk and absorb stages complete and little or no load) before initiating an EQ cycle. Wheather you use the MX of the FX to equalize will depend on available insolation (via the MX) or an external power source (via the FX).

    Jim / crewzer
  • dhilldhill Solar Expert Posts: 47
    Re: Battery Maintenance

    Thanks, guys. Thanks for the cleaning description BB. I think I'll shut everything down and disconnect. I have safety equipment so I'll be sure to use it. Messing with these batteries is the one part of this that I dread the most. I've seen a battery explode before and it isn't pretty. If I had a solar specialist in my area, I'd pay that person to do this kind of routine maintenance for me. Since I don't, I'll do it myself, take more time than necessary because I'm overly careful, and probably thaw out the ice cream in my freezer while it goes unpowered as I work. Of course, I could put the refrigerator on my portable gen, but I'm not sure that the motor would like that sine wave.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Battery Maintenance

    i am in total agreement with all that's been said and add to it safety glasses if you're not using a full face mask because you forget you are around sulfuric acid.
    as to the batteries it could help to rearrange them once in awhile for series arrangements. no not every month, but every year or 2 or 3 is perfectly fine as it could help in the balancing of the batteries. the end batteries, or posts in the case of a 2 battery 24v system, seem to take a slightly higher brunt than those in the middle do and thus creating an imbalance over time that an eq won't necessarilly cure.
  • BB.BB. Super Moderators, Administrators Posts: 33,085 admin
    Re: Battery Maintenance

    Generally, generators have pretty descent sine waves... The issues typically are voltage and frequency (to high/to low)...

    If you have the handy kill-a-watt meter, you can monitor both voltage and frequency and keep them within specs (within +/- 5% for frequency would be good; if you go outside +/- 10% I would begin to worry).

    One way you could check if your fridge is OK on the generator is to monitor its current, watts, and Volt*Amps (VA)... If the current, watts, and/or VA is much higher than normal (running on your inverter), that would indicate problems (low voltage, low frequency, and/or other issues).

    In any case, if you finish within four-six hours, it probably is not worth firing up the generator to run the freezer anyway--unless you want to get some runtime to check the generator for winter and change the oil after you finish the batteries.

    Also, you may wish to have a couple extra battery cables handy if you find any that are corroded or fail while you are cleaning and save having to go back in a few days later when you have the parts.

    For an experiment--if you want to try, place a heavy load on your battery bank for 10-20 minutes and then check the temperature of the batteries, cables and connections... Anything that is a tad bit warmer than its neighbors probably indicates poor connections or internal corrosion of the cables.

    The otherway of checking would be to again, use a heavy load on the batteries (charging or discharging) and instead of measuring temperature, use a Digital Volt meter and measure voltage drops using the millivolt scale. Check each cable, (+ on one end, - on the other) and record the voltage drops. You can also measure the voltage drop from the center of the battery post to the connecting cable. And, while you are doing this, also measure the exact voltage of each battery under load (only applies for series connected cells--parallel connected batteries should all read very closely to each other--unless there is a bad connection).

    These types of tests would be good to preform both before and after servicing the batteries. Any readings that stand out (or show dramatic changes between cleanings) probably indicates problems.


    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • dhilldhill Solar Expert Posts: 47
    Re: Battery Maintenance

    Thanks, Bill. Hadn't thought about having some extra cables around, but that's a good idea. My bank is in good shape, mostly just a little accumulated dirt. I check the water level fairly frequently and haven't had to add much. The cables are starting to get a little corrosion, a couple more so than all the others so those are the ones I'll target, but I've used the spray the battery supplier gave me on the post and most are perfectly fine. With the cooler temps outside, I figured this would be a good time of year to do a thorough cleaning. The batteries are in an open area with lots of ventilation so I'm not worried about any kind of gas build up, but I may place a fan in there and blow it all out anyway, just to be safe. Thanks to each of you for all the recommendations and sound advice.
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