Battery charging concerns.

Some/many newer chargers have an AGM setting, check yours. AGMs are very similar to flooded batteries and as such should be recharged ASAP. And as a general guideline do not discharged below 50%.

Most tow vehicles do a limited charge of trailer batteries. Yours may/may not completely charge the trailer battery with a day's driving. There are solutions like upgraded wiring and/or installing a DC to DC charger in the trailer.

No, having multiple charging sources all charging at the same time will not hurt at all. The lesser voltage charge will not even matter, it is only the highest voltage charger that is charging assuming the battery is not near depleted. IF depleted then the others might contribute, but that is info that is really of no use to discuss.

You are in TC forum so possibly your batts are closer to the alternator than would be in a trailer, but unlikely as I always see the wires connect from the back of the truck, then run in the bed to the front of the TC then out to battery. If you want more from your alternator then shorten that distance, cut out the going to the rear of the truck, and just wire up through the front of the bed and somehow run the wire as direct to the battery as you can.

Anderson plugs are good for making the connection.

Otherwise the slow charge from the way it is will be fine.

You can run solar, be plugged in with your charger going and run the truck motor/alternator and this is fine for the battery.

The best charging is an AGM specific "smart" charger though.

Alternator will not hurt the AGM. If anything it will probably under charge. Still good to get any charge into the battery.

You will need to post the converter model for best answers for charging on utility/generator power. Some are excellent, some are miserable.

You want a 4 stage converter, like the PD charge wizard set up. Depends on what you have now though, may be good to go already. The charge wizard thing is nice because you can manually put it into boost mode, thats helpful when your on a generator especially. AGM's love a full charge, but they do charge quicker than regular flooded batteries they say.

If you want to charge an AGM battery without spending a fortune, I would recommend a smart battery charger for an AGM battery, like one of these:

AGM Smart Chargers from Amazon

AGM is still lead-acid battery, so when it allows slightly higher charging rates, the flooded battery principals still apply.
Camper chargers went long way in last 20 years, so it depends what unit you have.
I found that when you heave deeply discharged battery - it will trip charging circuit breaker on the truck as well on converter on my 20 yo TC.
The automatic breaker will cool down and restore the charging, but that leads to very long hours to recharge.
That is why I am also carrying automatic charger with me, who monitors the battery stage and adjust charging amps.
For single battery you want 10 amp, for dual batteries 25 amp charger.
But beware that some chargers can have 15v boost mode, so better disconnect sensitive electronics for the time.

Grateful for all the info.
I have purchased smart battery charger.

rv convertor is magnetek model 6332

Does Closed AGM Weize 100 Ah battery requires ventilation?

If spending money I would have replaced the MT6332

https://www.bestconverter.com/PD4655V-55-Amp-Converter-Upgrade

Technically yes the AGM can vent and needs to be ventilated. Many ignore the issue. Very rare to vent.

The main purpose of developing AGM technology is the option of using them upside down (how often you do it with your TC ?) so they don't have so-called vents, but they do have what is considered safety valve for extreme situation.
Regardless, using them without the vent is acceptable, but read the battery label as technology can have variations.

Siakzar wrote:
Does Closed AGM Weize 100 Ah battery requires ventilation?

An AGM battery is a type of "Valve Regulated Lead Acid (VRLA)" battery.

If you have a "good" charger properly regulating the volts and amps for AGM, then any generated gasses "should be" continually trapped and reabsorbed within the battery.

If you're not careful, gasses can build up and the safety valves can vent the gasses. Having ventilation or at least being careful where you put the AGMs is not a bad idea!

--tg