Hide Transcript
Transcript is auto-generated.
hi everyone jeff cote here with boatingtechtalk.com uh we've got a question from a fellow voter uh gregory asked jeff i've got a perkins a 50 horsepower diesel with a victron orion tr a tango romeo smart 12 to 12 meaning starting voltage is 12 volt output voltages 12 volt 18 amps isolated dc to dc charger work well with a ball mark 100 amp alternator to charge a 400 amp hour dakota lithium battery bank okay lots of jargon in here uh let's sort of demystify the darken right for all of us because once we demystify the jargon then questions make more sense so for context uh gregory's telling us that he's got a diesel engine and he's got a 100 amp alternator onboard a bulmar 100m um and his challenge is how does he get his 100 amp alternator to recharge his lithium battery bank so what gregory doesn't tell us in the question but we can safely assume and we've got to put some parameters here right uh the parameters are that most likely his alternator is directly connected to his engine battery and what gregory's trying to do is he's trying to share the charging voltage from that bulbar 100 app alternators running off his perkins 50 horsepower engine he's trying to share that charging voltage with his house battery bank which is made of a 400 amp hour dakota lithium battery bank all right so that's why gregory's choosing a 12 to 12 dc to dc charging converter right smart he's going with an isolated model again i we most most of the times we choose isolated now the rate limiting factor here is 18 amps you know i'd have to say gregory an 18 amp charger you know if your alternator is opening 100 amps and you've got an engine battery most of that capacity is not going to be needed with your engine battery so your lithium is only going to draw about 18 amps out of that available 100 whenever there's a charging voltage so it will work but it's going to take you a long time it'd be like filling out an olympic pool with a tiny garden hose right 18 amps is not a lot of power that's why you have 100 alternator imagine having an 18 amp alternator not a lot to brag about right there's no set i mean generators maybe have a 10 15 20 amp 30 amp alternator it's tiny so it will work but it's going to take a really really long time and it would be aggravating to run that alternator which is decent size to only get 18n so i would suggest to consider a 30 amp alternator a 30 amp a dc to dc converter and some folks would actually install two of them in parallel so that you can get a net 60 amps of charging because remember your 100 amp alternator is never going to output 100 amps not when it's hot that's a cold rated output so you're generally going to see about and again assuming that you have a smart external regulator which you should uh but if you don't you know you're looking at you might get about 80 85 ounce tops out of that alternator once the alternator is hot and less if it's internal regulated because it's just overly cautious so i would say you know if you've got a smart external regulator on that ball mar then i would suggest to consider the 30 amp model and you know on some boats we actually installed two of them in parallel i've done three in parallel so there you go good question gregory um good on you to think about that uh because we can't and this is very important for all of us because otherwise we're gonna learn the hard way it's much easier to learn from others than ourselves right making our own expensive uh sort of discoveries or mistakes um is that when you have an alternator an alternator is set to only one charge profile right so it can charge agm it can maybe whatever it is but if you've got mix and match battery types one battery type agm or lead ass flooded lead acid for your starter and then a lithium for your house many of us are going to basically share that alternator via dc to dc smart charging converters just think about the size um because otherwise it's just going to take forever for that engine or that alternator to recharge the house battery bank via a dc to dc charging converter so great question gregory thanks for asking all of you out there that have solved this problem share please you know what i mean that's the whole point of doing this i learn as much from you as you do for me by the way um it's amazing i read every single comment that gets posted the good and the bad and you know what it's it's worth it because uh i learned something every time i go on that site and i see what you share so thanks everyone for doing that all right and keep watching if you're curious we've written whole articles about this go on our website search it out and we've got a lot of other tech talks about this very topic if you haven't subscribed to this channel please do it actually it really does make a difference it encourages to keep posting so if you're watching this video and haven't had a chance to subscribe we really do care because the more of you that are watching the more of us over here are willing to spend more time in creating content so thanks again Tools Tools