Booster, what AC charger are you using on your lifelines? My NOCO doesn’t start charging until voltage drops to 12.6, which presents an obvious problem, as I also have Lifelines.
We have a Magnum MS2000 with an ARC-50 remote, temp sensor, and battery monitor kit BMK on it. It was pretty much the only shore charger I could find that would do charge control off the internal battery monitor and shunt so we get true amp controlled charging every time.
What is unfortunate with Magnum is the same as you see with the NOCO, a it won't go into a full charge cycle if the voltage is in the 12.7v range. I talked to Magnum about it because the unit does charge ever time in CC/CV mode, and they said it is an error on their part as it is a carryover for previous units that didn't have the better control through the monitor and could overcharge running a full timed cycle every time. They said they are going to try to correct it at an update if they have enough capacity to do so in the hardware. It would only run a full cycle when turned on if you had the BMK kit on it and was set in "amp control" mode. I don't know if the newer ones have changed, though.
In real world use, it is only a minor inconvenience for us as the ARC-50 allows manual charge stage control forcing. If we stop driving for the day with some surface charge, or the solar is holding up the voltage and Magnum goes to float when we plug in it is just a couple of button pushes on the remote to start a full cycle. There is no risk of overcharge because it is battery charging amp controlled so as soon as the battery is full or even if it starts full, it will go to float at the correct return amps for 100% full.
I just took a quick look at the NOCO site and it appears that they are algorithm/timer based chargers so don't monitor battery charging amps unless they do it internally. With no settings for actual battery capacity it is unlikely they do any other than volts and time algorithm control, so if your charger went in to full charge every time, it might overcharge or just go to float right away before doing anything. This is the reason that many/most smart chargers won't do a cycle on every plug in unless the voltage of the system is low enough to justify a charge. They know that chronic overcharging is very bad for the batteries and worse than the lesser damaging undercharging. Sometimes, you can fool a charger to start by turning on some high load items on the 12v system to drop the voltage. Once it starts charging, you may or may not have to leave some of them running to keep it charging. Some chargers, once started have a hold time at absorption voltage that is timer based so they will charge for that long once the stuff is shut off.
It does not look like the NOCO has any way to force the stages so you wouldn't be able to use it like we do with the Magnum. Progressive Dynamics chargers with the Charge Wizard can be run manually and force stages, but they are one of the few.
Of the available smart chargers, the only one I know of that will run a charge cycle without worrying about voltage is the Blue Sea Systems unit, which is a very interesting charger. We used one for a few years successfully and it always ran a cycle when turned on. It has 3 isolated outputs and measures the output amps internally. The amps can be set to control the charging so you can get very good charging with them, but you have to put your loads on one bank and the batteries on the another so the loads don't mess up the amp readings to batteries during charging. I rigged a simple relay setup to switch a connection between the two banks together when the charger was off and open when the charger was running and it worked well. I still have that charger and use it for a bench charger sometimes as I can set the amps way down to do small batteries. It is 40 amps max. We went to the Magnum when we went to the 440ah battery bank of Lifelines from our previous 260ah of Trojan GC2 wet cells to get the higher output of 100 amps of the Magnum. Most places get about $700 for the Blue Sea 40 amp version which is the largest they make. Biggest downside is the charger needs to be easily accessible as all the settings and such are done directly onto it, not on the remote, as is any monitoring on the unit screen.
There are a few other smart chargers around that measure amps internally and are settable, kind of, in large steps but they have no way to isolate the loads so not as good for accuracy of charging as the charger thinks the loads amps are going to the batteries. Some of them might start each time turned on as they woudn't be so likely to overcharge. There are a lot of specs on chargers around this forum, but probably hard to find. It is best to look at the manual for chargers and see what they let you set, and if there is a amp setting other than maximum is it worth investigating what it does. Those are also the chargers most likely to run a full cycle every turn on.
