Forum Discussion

greenrvgreen's avatar
greenrvgreen
Explorer
Jul 23, 2015

Simultaneously Draining/Charging AGMs?

I have a small bank of 3 or so 35ah AGM batts, the UPG Chinee Goodees. I have two chargers for them: a Meanwell SP-200-15 (13.4A) fo bulk charging, and a two-stage 4.5 amp charger which boosts at 13.7 V and then tapers amps to finish (constant V).

MY QUESTION: What is the safe maximum V I can set the Meanwell to when simultaneously powering an inverter at high draw (400W)? My only readout of bank V will be at the posts, so I want to know the V I should set the Meanwell to (it might be charging for hours and hours) and also the max V at the posts. Thanks!
  • time2roll's avatar
    time2roll
    Nomad
    Jul 23, 2015
    You are talking float voltages when you say continuous so I will give 13.4 volts in general conditions. Review the float specs listed on the battery. Extreme heat or cold should get an adjustment.
  • MrWizard's avatar
    MrWizard
    Moderator
    Jul 23, 2015
    my experienced ? guess would be anywhere between 13.8 and 14.1
    this is float range and can be held indefinitely
    i have my Solar cranked up to put 14.1 at the batteries
    and when i do my once a week BD vector top off i try to go to 14.8

    i (4) 60ampHr agms and (4) 139ampHr agms

    you are charging Unless you exceed the output of the chargers
    at that point you are discharging, just doing it at a slower rate than if the chargers were not on, this will cycle.. charge - discharge as the loads change, but it is ONE or the Other
    not both at the same time.. but we know what you mean
    if shore power is available for days at a time, i suggest high end of float voltage

    you can go higher if it is only for a few hours

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,211 PostsLatest Activity: Mar 11, 2025