Newbie to pup and solar

Discussion in 'Power - Site Power/Batteries/Generators/Solar' started by Rita Mintert, Sep 12, 2020.

  1. BillyMc

    BillyMc Well-Known Member

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    That is a large inverter! I have a 150 watt to run the air mattress pump if needed. If it requires more than that it doesn't get used or I bring the inverter generator. With everything left turned off does it hold charge?
     
  2. igam

    igam New Member

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    That brings up a couple of good points.
    Yes, AGM batteries are lead acid and hydrogen, which is acidic (low pH) is created during recharging. Unless you are using a good quality three tier battery charging system, you can easily overcharge causing excessive gassing. However, the AGM is a SLA, sealed-lead acid or valve-regulated lead acid battery where-in the hydrogen is to be absorbed internally. This eliminates the requirement to vent for gassing in an RV with proper charging, The normal FLA, flooded lead acid battery must be vented to eliminate the buildup of hydrogen in the cells, which would create a serious hazard to life and equipment.

    AGMs tend to not hold a charge as well as FLA, thereby needing maintenance charging if out of service. Depending on temperature and humidity, AGMs can be damaged if not charged for 6 months. AGMs need to be used. FLAs may not be quite so delicate, but you should not push your luck.

    AGMs can typically be used to 60% discharge where standard FLAs should not typically be drawn below 50%.

    Lithium iron phosphate batteries can be installed in any position and can be discharged to as low as 95% without damage.
    This means with a 100 aH lithium battery you can use 95 aHs, but with a 100 aH FLA only 50 aHs and maybe 60 aHs with an AGM. At these rates you probably won't damage a high quality lithium battery, but you quite possibly will damage the AGM or FLA or at least reduce the ability to cycle to full capacity if you go beyond these numbers.

    AGMs can be installed in less than a straight upright position.
    Lithium batteries can typically be installed in any orientation including upside down.
    Check with the manufacturers.

    A top quality lithium battery can be cycled (charged) 2000 to 5000 times, which is far more than typical FLA, AGM or Gel.
    Lithium batteries can cost 5 to 10 times more than comparable FLA, AGM or Gel for the same aH . However, they not only last much longer, you get more usable aH out of them per charge. This is particularly important when charging with solar.

    Example:
    If at the end of 12 years you have installed 4 individual batteries in your RV, each lasting 3 years and consider inflation into the cost of the second, third and fourth batteries, you will be ahead with one initial lithium battery that will produce 80% of the original aH after 10 years, because it was overall giving you more usable aH than the typical FLA, AGM or Gel.

    Remember that the non-lithium batteries typically should only be drawn down to 50% of their aH rating at time of purchase and that amount dwindles with each month of age and cycle.

    If you are super diligent about your battery, all the above types may do better than described, but only the lithium will give as much of the original capacity.

    All references here to lithium are for lithium iron phosphate batteries and not other lithium chemistry.
    The above reference to lithium batteries generally relies on specs for the Battle Born 12v 100 aH battery,
    The above performance ratings are general industry standards and your experience may vary.

    As for insulating her battery from a cement floor: Depending on the humidity, if a FLA battery is left on a damp, winter or humid summer cement floor without a charger, it will self-discharge at a rate of 4% to 21% more than if kept insulated from the floor, unless the humidity is below 50%. If you leave it on a charger, you will then lose some cycle life. I was involved in this testing several years ago for the marine industry.

    Kind thoughts to all!
     
    wusthof and Econ like this.
  3. jmkay1

    jmkay1 2004 Fleetwood/Coleman Utah

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    What happens if you completely disconnect the inverter? Perhaps that power button is not shutting off the inverter itself but only to the plugs on it. However the inverter itself may be pulling a parasitic charge just by being plugged in. Something I read in a science book, that despite popular belief an item can still be pulling A little power even if said item is turned off. Hence parasitic charge. It only stops pulling power when you Completely disconnect it. So perhaps add a separate switch on the line just before the inverter. That way you are essentially disconnecting the inverter from the circuit. One of the reasons inverters are so inefficient is because not only does the inverter pull power for the devices using it, but also pulls power for the inverter itself.
     
  4. Rita Mintert

    Rita Mintert New Member

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    Thanks! the battery I have now is about all I can afford/willing to put into it right now, after everything else needed to get this thing even just up and running was already way more over what I budgeted for, so for now I have this one and will hope I can get the most use out of it with proper care. In the future I will definitely know to get a different option for my own peace of mind I think.
     
  5. Rita Mintert

    Rita Mintert New Member

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    I may take her out this weekend. Weather looks decent and I will not use the inverter in the camper at all and see if that makes a big difference. Like I said I really only got the 2000 watt one because it was the same price as the smaller one but I am still within my timeframe to return it if I decide I need too. I will also be wiring in a fuse block and some fuses this weekend so fingers crossed for me. Thanks for all the help, I will update when I figure some things out.
     
  6. rabird

    rabird Howdy!

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    still wondering what are the signs that it doesn't last?
    did you ever report any voltage reading(s)?
     
  7. igam

    igam New Member

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    Don't worry. You did not buy the "wrong" battery. It just won't last as long or give you as much usable "power".
    You will soon know how much you can get from your battery. Just don't drain it until it is dead. Be a bit miserly your first few trips and you will get a feel for it.

    Most importantly, go and be safe!
     
  8. don evans

    don evans New Member

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    I would highly suggest returning it for a smaller unit. Figure out just exactly what you want to use the ac power for and you can gauge from that. I'm guessing a 750-1000 would be quite sufficient. The invertors are quite inefficient so bigger isn't always better.
     
  9. igam

    igam New Member

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    Keep this formula in mind with all your electrical purchases and usage: Volts times amps equals watts. V x A = W
    and W / V = A


    A modified sine-wave inverter will do okay for a lot of things. Computers don't like them but the will usually work. Refrigerators and AC compressors often run hotter than they should. Ten minutes of reading will make it clear.

    If your converter is still returnable, the price is now $129 so you might try going back for price guarantee and using that amount for extended warranty if you do not want to simply return it for a name brand known in the solar community. I would definitely avoid Renogy components (other than maybe their panels) any time you can due to high price and reliability. They are not "bad". It just seems that they are not as good quality as you can buy for about the same price.
    Hopefully you can find the specs on the inverter and determine what the idle power consumption is. That will tell you how much you will have to generate from your panel (or charge your battery with an AC park connection} to run the inverter each hour. Subtract that amount from HALF of your FLA battery capacity and you will know how much you have left to run AC (110v) items without charging at the same time.
    While you are boon-docking, will you NEED 2000 watts? What will you need your inverter to run? Do you have to run AC, refrigerator, TV and lights all at the same time? If you do not HAVE to have it now, could you save up for a little while using 12 volt only and then buy a pure sine-wave inverter such as by Epever or Giandel. Both are well known, seem to be very reliable and close to your price range.

    Kind thoughts to all!
     
  10. BillyMc

    BillyMc Well-Known Member

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    For 2000 watts you may want to consider getting the inverter money back and putting it towards and inverter generator. I bought an Ironman 2000 open box (no warranty) for $200 and couldn't be more pleased. It's really convenient and gets used camping and at home. I was going to put power to the storage building out back, but this thing covers any needs back there with two or three pulls of the rope. Only way I would be happier with it is if it was parallel compatible. You can get a Rockpals r2000i that is parallel compatible for under $400 and looks like my generator with parallel and USB connections added.
     

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