Charging batteries with generator help.

[Wabbit]

Looking for a "how to" charge my batteries with a generator.  Currently I plug a 2/10/25 amp Walmart charger into my 1000w generator. This brings my batteries to 14.4 and calls it a day(stops charging). I want a better setup. If its possible, I want to start my generator and have the charging go to whatever I set voltage to(like 14.8 or 15.2) until I stop it. I'm not sure where to start. Any links, search terms, ect that you have would be great. I hope this request makes sense.

[sternwake]

Meanwell rsp-500-15

40 amps to seek then hold any voltage you dialed in previous to hooking it to battery

Can run in parallel with your other charger, but at 25 amps will likely overload generator . So set it at 10 amps. Then plug in meanwell. They will work fine together. And once batteries can accept less than 40 amps. Remove other charger and run meanwell as long as you feel like listening to generator

[Trebor English]

I have an old battery charger.  It is rather dumb.  It is like a PWM solar charge controller.  It holds about 14 volts until you unplug it.  It only does up to 8 amps max.  

What you can do is put a load on your battery to discharge it a bit then disconnect the load and reconnect your charger.  It will charge a bit more.  Try a load and charging together.  Obviously use a load less than what the charger produces.  The charger may declare the battery bad and stop.  To try again you may have to unplug the charger.  

10 amps at 14.4 volts is only 144 watts.  While your generator is running you probably want more amps to get to 14.4 volts quicker.

I searched for "RV converter charger" and got these two among many others.  If left connected for a month they might roast your battery, not a problem with a generator.  They may be so smart that they shut off to protect your battery from sufficient charging.   55 amps at 14.4 volts is almost 800 watts.  That should work with your 1000 watt generator and charge quicker.  You still need to hold 14.4 volts for long enough for the current to taper to next to nothing.  My first wife's uncle put one in his class C RV and hasn't complained.

US $116.99 eBay 55 amp
https://www.ebay.com/itm/PowerMax-RV-Con...1785804168&hash=item43d332a095:g:DngAAOxyPLpRc66m:sc:USPSPriority!32934!US!-1:rk:1:pf:0&vxp=mtr

$117.88 Amazon 55 amp
https://www.amazon.com/Powermax-Supply-C...C440?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-ffab-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B00F8MC440

I also saw a converter for about $90 that was 35 amp.  That5's 500 watts and you might like that better.  In any case, 35 is better than 10 and staying on is better than shutting off.  The RV converter is supposed to stay on to power your RV 12 volt lights, water pump, etc so it should stay on.  It may cut back to only 13 volts.

[Wabbit]

Thnx guys, that meanwell is what I was looking for. Knew I heard people talking about what I want, but couldn't remember the term meanwell. Wheeee! Now there's another project I can totally screw up! Lol.

[frater secessus]

Is this a generator-only charging scenario, or is there solar to help with the higher-voltage duties?

[Wabbit]

Would be both. Generator in the morning if it hasn't been getting enough sun. Reading about dual charging setups, I see some issues with them not both playing nice together. I would wire the meanwell straight to the battery, not through the solar CC or anything. Right now with the Walmart ac charger, if the solar bumps the battery voltage to 14.6 for abit, the charger stops because it thinks batteries charged. I then can't start the AC charger because the voltage(with a lil solar going in) is reading 13.3 or something. But this is just surface charge. It's not a big deal, I just have to wait till later in the day when it's back to 12.5 or something and it will charge again with AC charger. Just be nice to have it setup "right" for battery life reasons.

[sternwake]

If the solar alone can maintain absorption voltage. Then. No other charging source required. But when solar alone cant achieve or maintain abs voltage. Then so called smart chargers will see the 13+ voltage and think the battery is fully charged. When it is not.

Meanwell gets hooked directly to battery. I use 45 amp anderson powerpoles.

The meanwell adjustable voltage power supply is built like a tank. But it was not intended to be maxed out for long periods of time. Some stick on heatsinks adjacent to transistors, and extra ventilation across it will make it happier.

[tx2sturgis]

 55 amps at 14.4 volts is almost 800 watts.  That should work with your 1000 watt generator and charge quicker.  

Careful, that 55 amp converter will likely have an overall input power requirement rating around 900-1000 watts or so.

Plus, when you add in the losses of efficiency ratings and power factor, a 1000 watt genset trying to run an inductive load of 800 watts or more, might not be happy at all. 

Especially if the ambient temps are high and/or the elevation is high.