Can I Use One Alternator to Charge an Flooded Lead Acid Starter Battery and an AGM House Battery?
Transcript is auto-generated.
hi jeff cote here with uh pacific outsystems we've got a question from a fellow boarder for our ask pys segment so here's a question and a pretty common one hi jeff i've got a stock alternator and by the way most of us do a lead acid battery for cranking and an agm house battery bank is it okay to install a battery isolator well the alternator undercharged the house agm banks because there's no external regulator all right well first of all let's just think about regulator your alternator if it has an internal regulator or external regulator can only really charge one profile so you've got to make a decision are you going to charge correctly your agm battery banks or are you going to charge correctly your flood to lead asset battery bank you can't really have one alternator to two things it can only charge to one profile so in this instance we've got an internal regulator which is going to charge the battery about to 14.4 volts okay that's basically what its target voltage is and that's a perfect target voltage for a flooded lead acid battery so putting a battery isolator on the output of that alternator is going to mean that the flooded lead acid battery which is for engine start is going to be getting the right voltage because the regulator is actually outputting for that battery and the agm battery is going to be chronically undercharged because it's not receiving an agm charge profile it's important to remember that a battery isolator is not this magical device that can actually regulate and change battery voltage it doesn't get an input and say oh by the way battery starting battery 1 wants this voltage and start and house battery 2 wants a different voltage it does not modulate or change convert the battery voltage for different type of batteries it's simply spreading sharing right the different battery banks to be charged from one alternator so ideally when we do this sort of systems i always recommend to boat owners especially if you're going to have one alternator charging two battery banks the easiest thing is to have all of agm right and because you want to have the best sort of charge profile if you have an agm battery bank it's definitely better depending on the manufacturer to consider an external regulator so that your battery gets the exact exact voltage on a three-phase charging curve so that the battery lasts longer but you can get away with just having an internal regulator to charge an agm it's not great but it will work it's just gonna chronically undercharge the battery and that's where a battery charger with the three-phase charging is perfect so make sure that if you've got a stock alternator with a stock regulator that you've got a compatible agm battery charger to recharge your batteries uh when you're not running the engine so that's a really good question thanks for watching this video if you've got further questions that we didn't answer please ask them below or go on our website and fill out one of the forms and lastly if you haven't subscribed to our channel please do so that way you'll get the regular contents and in closing thanks for watching you
