Is the 200 to 450Ah battery bank going to be deeply cycled...... Discharged to the 50% range?
Is this 200 to 450AH battery bank goibng to be flooded wet marine batteries, or AGm batteries?
If they are going to be discharged to around 75% state of charge (SOC), I would want flooded batteries to have no less than 10 amps per 100AH of capacity available for charging. If they are going to be discharged to 50% SOC I would say no less than 12 to 15 amps per 100AH of cacpacity
If they are AGm batteries I would want no less than 20 amps per 100AH of capacity if deeply cycled.
So basically the deeper the level of disccharge the more important it is to feed them at a higher initial amperage rate. It is not just a matter of lower amperage rates taking more time to get to a higher state of charge The higher amp flow promotes electrolyte flow around and into the plates.
TPPL agm's, thin plate pure lead, well Odyssey says that their batteries need no less than 40 amps per 100AH of capacity available, when the batteries are deeply cycled. Northstar is very siilar to Odyssey, I have one, It responds wonderfully to very high amp charge rates. My alternator can and does feed it over 100 amps when it is well depleted and the engine is spinning 2400+ rpm and my lights and blower motor are off.
If the batteries are never going to be discharged mucch at all, then the maximum amperage rate of the charging source becommes much less important.
People seem to dwell solely on amperage rate of smmart chargers, but as important as that is the max voltage the charger seeks, and once it gets the battery there, how long it holds it there. Smart chargers basically are not designed to 100% fully charge batteries automatically, they are designed to NOT overcharge them. As a result the voltages might be a bit timid, and the durations at which they hold them can be much shorter than actually required as it is much safer to undercharge than it is to overcharge. A hydrometer dipped into the cells when the smart charger first reverts to 'float' or maintenance voltage will,, 85% of the time, reveal the battery is not fully charged. But few ever bother with this reality.
Charging still occurs at float or maintenance voltage, and newer healthier batteries will likely eventually get fully charged at coltages in the low to mid 13's, given enough time( days), but older batteries stand little to no chance of achieving a true full charge at lesser voltages. Again provable if one were to dip the cells with a good turkey baster style hydrometer with electrolyte temperature compensation, like the OTC 4619.
Remember there is no magic circuitry which penetrates a battery and determines full charge and then flashes the green light indicating full charge. Full charge is only verifiable on flooded batteries by using a hydrometer. The green light on 'smart' chargers simply indicates that the charger has decided to not hold the battery at higher voltages anymore.
On AGM batteries full charge can ONLY be determined when the battery is held at absorption voltage, and the amperage required to maintian the battery at that voltage tapers to just 0.5 amps per 100Ah of capacity. Since few to NO 'smart' charging sources actually ask for the AH rating of the battery, they cannot determine full charge, when to stop charging or how long to hold absorption voltage, and their green light is just a guessing liar which mocks the human who believes it
While smart chargers usually stop charging when in the 92 to 95% charged range, this level is only half as good as getting the battery to a true 100% state of charge, but getting the battery to 95% charged is 5x better than 85% charged.
Since I do deep cycle batteries, and ask them to also start engines, I gave up on 'smart' chargers, as they were allowing batteries to prematurely sulfate, as I could not really get them to truly fully charge the battery. I would have to restart them over and over, and this required loading the battery to drop voltage below 12.8 or 12.6v then restarting the charger. Even then multiple restarts would be required and basically the smart charger required a lot more input and babysitting than would a manual charger.
I now use an adjustable voltage power supply. It is capable of 40 amps at any voltage I choose from 13.12 to 19.23.
In general I choose 14.7v, or 13.6v. i hold 14.7v until amps the battery accepts taper to 0.5% of the battery capacity, 0.5 amps per 100Ah of capacity, then lower to 13.6v, or simply unplug powersupply at that point.
This powersupply is a Meanwell rsp-500-15, but I have modified it with a better voltage adjustment potentiometer, and more ventilation and heatsinking. It is not an Automatic charger and can indeed overcharge batteries if set to a higher voltage and left on for too long. A spring wound timer would be of benefit if I were scared of holding too high a voltage for too long. I meant to rig one up but never have in the 5 years I have been using this power supply. There are cheaper adjustable voltage power supplies available like from here;
http://www.megawattpowersupplies.com
These are not designed to output their maximum amperage for hours on end though and would benefit from better ventilation and heatsinking if charging large banks of depleted batteries. The voltage adjustment potentiometer they come with is only rated for 50 cycles too.
Powermax rv converters, which are basically heavier duty battery chargers, well they do have adjustable voltage models. One must provide theier own DC cables to the battery bank.
Progressive dynamics RV converters have a 92xx series of converters, the XX is the max rated amperage output. These employ 3 stage charging, but these models have the option of manual override. Press a button and one can command the converter to seek 14.4v, for 4 more hours, or force it into 13.6 or 13.2 mode. While these converters do not come inside a sexy marketable package, they are very capable and many fold more effective at recharging batteries. PD9245 PD9260 and PD 9270 all can plug into 15 amp household outlets, and output 45, 60 or 70 amps maximum at any of those 3 voltage stages. Absorption voltage is set to 14.4v, but they have 14.8v models available. RV converters have larger 80MM computer fans and much larger heatsinking. Cut off a set of jumper cables, up to 2awg, add a handle and these can be way more effective, and much safer than the giant wheeled chargers of yesteryear. Automatic/smart charging with manual override option.
Powermax RV converters in higher amp ranges are also power factor corrected and they have a model which can output 120 amps, on a 15 amp household circuit. these are pretty much a custom order product though.
I do not like being asked to recommend any consumer grade garage style charger, unless I have actually seen how well it works. When people ask me to recommend a consumer grade garage style charger, I do recommend the pro-logix, only because of reading about them here on Bitog and their seemingly happy owners, but I have no idea/ actual data on just how long they actually hold absorption voltages(14.4 to 14.7v), and this is really key to truly fully charging a battery, and truly fully charging lead acid batteries is absolutely critical, if one is trying to achieve maximum longevity of the battery.
If the battery is going to be charged well outside the 77F temperature at which all battery manufactures list their charging voltage specifications, then a charger with temperature compensation is quite important, to achieve or approach ideal recharging.
Ideal recharging can be taken to extremes, which can get very expensive if one wants to do so automatically, so 'good enough' while subjective, is just that, and especially if the lead acid battery bank is not going to be deeply cycled often, and not exposed to wild temperature swings where one would want to either decrease or increase absorption voltage to match.
But if a 440Ah bank of batteries is going to be deeply cycled, I would not trust any consumer grade garage charger to do a good job, and would spend the extra for an Rv converter with at least 60 amps available.
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