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Comments for Keep those expensive RV batteries alive!

  • I need some clarification, please. When you say “Discharge down to 80%” do you mean there is 80% of capacity left in the battery or do you mean there is 20% of capacity left in the battery?

    • I being in the battery business since 1983 and owning a chain of retail battery stores..he means discharged down to 20% remaining..very simply the deep discharges shorten the life of most batteries in the RV world but the older other type of batteries such as camcorder needed deep discharges and then recharged fully as to prevent memory problems but this does not relate to your question..Similar to your auto recharges immediately after starting thus your car batteries last usually 5 years except in super high temp climates and those batteries use a different low heat plate..Keep in mind the #1 killer is Heat ..#2 Vibration…Hope this helps..

  • I think Russ stated the scale BACKWARDS. Yes, you discharge less/keep more charge to lengthen the life.

    He also unrealistically described rest, because unless you disconnect the battery, there are always some parasitic loads drawing down the voltage.

  • I don’t know if it showed up better on a desktop or notebook computer but the chart columns for flooded and lead acid were so out of line on my iPad they were indecipherable. And say again that discharging down to 30% is better than down to 50%? Might have been answered by Bob.

  • Testing voltage of a battery in use or recently charged will not tell you the state of charge with the table above. ‘That table is for disconnected static batteries. When it reads 13.1 right after you’ve been charging it…that is a surface charge and you don’t know if you have 100% charge on the battery or 80%. It takes time disconnected (24 hours!) or a dummy load ($20 bucks at harbor freight) to get a true reading.
    Of course a battery in use will exhibit lower voltage than when disconnected as so you could easily be seeing voltage corresponding to 80% discharged when the actual state of charge is much higher and the voltage will rise when the load is removed.

    IF you boondock you need to know the REAL state of charge of your batteries, how much you’ve used, how much is left at your present rate of use …and when you can turn off the generator cause you’re batteries are full. This requires a true battery monitor like those from Trimetric or Victron. The batteries and gas you save will pay for the unit.

  • OMG: I’ve been camping/RVing for 50 years & will say batteries have been the most understood & most talked about issue ever! Everyone has different usage & different circumstances, so its really hard to show all the different usages. Actually I’ve had the best results with 2@ 6V off brand batteries for my boon docking. I had a 125W solar panel that keep everything going, except if we ran the heater all night! In todays RV’s with 110 volt everything, it makes it difficult to dry camp, unless you have mega L16 AGM batteries & 800 watts of solar! PS: I still dislike GENERATORS!
    I’m thinking maybe there might be something else thats not understood & thats shock absorbers & springs, hmmm!

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