Connecting EG4-6500EX to grid for backup battery charging

[wildhorsesracing]

I have two(2) EG4 6500EX-48's connected to 6 EG4 LifePower batteries and after a week of little or no sun we have depleted the batteries down to 19%. I never connected the EG4's to the grid side power and have been using this setup for a few months now and so far everything has worked well "off grid".

I was considering adding a 30A RV plug to each 6500EX since I already have an RV plug on my house for my RV and it is powered by the local utility company. I could plug one of the 6500EX-48's to use in emergencies when my Solar can't replenish the batteries.

What do you think?

 

[Djbodya]

So I have tinkered with this set up in the past. I have one 6500ex and at that time had one battery. After getting it all assembled I ran grid power to it and was tripping the GFI's in the garage and outside, with God knows what issues. I connected it with a extension cord in the house and it was fine using grid to top off the battery.
I consulted an electrician and he checked out my outlets, told me they are wired incorrectly and he will help me fix all that.
getting back to the set up, the grid did top off the battery with no problem. I did not pull any loads at that time so I don't know if that would work, but charging was no issue.

 

[wesselcamper]

My few cents:
Once you have an MPPT solar charge controller available in your system using this you can use any DC voltage you have allowed within MPPT charger & battery combination range allowed to feed power in, This MPPT has no clue whether energy comes from solar panels or from laptop charging bricks, DC power supplies, LED power supplies, other battery banks or wind turbine chargers, just make sure your peak voltage is below max limit of MPPT.

Same is true by the way for a DC DC charger. When using already installed such a MPPT solar charger or a DC to DC battery charger (which -of course- should have been adjusted to your battery type (lead acid, AGM or LiFePO4 etc chemistry and over charge protection) your power input can remain "dumm" as the intelligence the comes from the MPPT or DC-Dc charger. For shore power charging you can just buy a cheap "brick" charger or universal DC power supply (eg MeanWell has several wide input voltage & power range power supplies . You can choose to prepare proper plugs to just swap when additional back up charging is required (eg when sun goes into hiding (nothern hemisphere of cloudy whether or too much shade). if you use properly dimesioned diodes you can use even in "parallel"" input .

As icing on the top I have a very small & light Honda EX350 generator (8.5kg only!!) of which I "stole" the internal 3 phase voltage and rectified that (with 6 diodes @ internal 230V side)) to power a (wide input range) MeanWell DC power supply....

(not any link or commission from MeanWell, but as they are easily available, decent quality and relatively cheap like to use them)

Hope to trigger some ideas , Wessel

 

[wildhorsesracing]

I forgot that our house had two(2) water heaters when we purchased it 30 yrs ago because the previous owners had five(5) teenagers taking showers and doing laundry. We had removed the 2nd water heater when it failed ~10 yrs ago but left the wiring in the panel and basement. I moved the wire to be near my EG4's and connected it into the utility input side of the units. The wire was 6 AWG connected to a 30a 240v breaker so I simply changed the parameters in the EG4 to not pull any more than that from the grid. It has worked so far, but we have only dipped below 30% battery once since I connected it.

 

[wesselcamper]

Your battery SoC (state of charge) will only go down over time if the "average" or integrated kWh of consumption is higher than the "average" or integrated kWh of charging . Of course a battery bank cannot absorb charge anymore when it is (almost) full and a charger cannot "push" charge in the battery bank when the bank doesn't want to "swallow" it anymore.. If your battery bank SoC doesn't reach the "full" state regularly (eg. once in a 2 week period, you might want to consider to topple it up with some additional input (or connect some of your high power consuming equipment directly to the grid (and not powering them via your 48V & invertor system) .. of course make sure any cable is properly fused (as adequate circuit breakers"" on each site from where power can come to avoid fire hazard and also put proper warnings if your system has multiple power inputs as "main power switch off" might not switch all power off..