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!

my experienced ? guess would be anywhere between 13.8 and 14.1this is float range and can be held indefinitelyi have my Solar cranked up to put 14.1 at the batteriesand when i do my once a week BD vector top off i try to go to 14.8i (4) 60ampHr agms and (4) 139ampHr agmsyou are charging Unless you exceed the output of the chargersat 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 Othernot both at the same time.. but we know what you meanif shore power is available for days at a time, i suggest high end of float voltageyou can go higher if it is only for a few hours

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.

Do experiment and charge all three at 14.4 volts and watch the amperage as it declines. When it drops to 1 PERCENT of the amp hour total of all three batteries (added together) --- reduce voltage to 13.6 and keep an eye on float amperage. It should never increase beyond that magic 1% calculation or if it does the batteries were not bulk charged long enough or you may have a drone in the three. Test them.

I thought our expert would get here, with solid device

400w you are going to be pulling about 30 amps maybe a little moreso that is 17 from your chargers and 13+amps from the batteries, for the duration of the power drainalmost everything here except MW and A/C are on inverter, but my charger is 100ampsaugmented by Solar

Simultaneously Draining/Charging AGMs? | Good Sam Community

NinerBikes
Explorer
Jul 25, 2015
I run a megawatt S350-12, 29 amps output, on a Honda Eu1000i. Drop the voltage, Borg charger style, at start up of charging, add voltage with 10 turn pot as necessary to load the motor to a reasonable level. MaxV for an AGM is 14.4
v for most models, 14.8 for flooded lead acid batteries.

Other option for me is just leave the V set at 14.8V and plug it into the Eu2000i in Eco mode, and let the chips fall where they may.
greenrvgreen
Explorer
Jul 25, 2015
That was my first gennie, the Champion 1200 that Wiz posted. While I got good service out of it for several years, for me it was neither fish nor fowl: At 40 lbs it's not exactly light (and it's also quite bulky), and 1200 watts wasn't enough for me to run my TT. So I retired it when I bought my Champ 3500, which I continue to love, although it mostly sees duty as home backup these days.

Lately I've been doing more tenting, and all of the gear mentioned in this post is for tenting, and EVERYTHING must fit in or on my Jeep Grand Cherokee.

Regarding more batts, yes of course, but before I get the batts (and make room for them in my car), I have to get more charger power. And before I can get more charger power I have to get a (compact) gennie that can run it, which I'm taking delivery of next week.

Worth noting that the wonderful meanwell sp-200-15 that I bought several months ago I've now accidently smashed and broken, in the only place you can actually break these things that are built like little tanks: In the teensy voltage adjustment screw that is inset for protection, but not far enough to defeat me. So I've also got another Meanwell coming!

The gennies that I'm talking about are the Powerhouse 500/450 and the Powerhouse 1000/900. The little 500 has performed remarkably well for me, and it's not much bigger than a shoebox and weighs 21 lbs. The 1000 is bigger and weighs 32 lbs, but I gotta have the power, so I'll make room for it.

I've been using the technique of starting the voltage low and working up, but simply restarting the gennie and trying a second time works equally well. On the 900w gennie, if a second meanwell chokes it I could see using this technique for the second unit, so that it provides an early boost but doesn't cook anything.

Thanks!

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