jungpeter
Guru
I’ve recently completed an extensive battery rework on my 1978-vintage Tollycraft 48. This rework has resulted in a 1250-AH house battery bank (Fullriver 6V AGMs), and a single Fullriver 8D AGM as a start battery for both main engines.
Battery charging duties while dockside is accomplished via a Blue Sea Systems multi-stage 40A “smart” charger. While I recognize this charger is marginal in capacity, I’m assured by Blue Sea that it is up to the task, and will not be overloaded in any way, even while charging such a large house battery bank. It’ll simply take a while! This charger has three charge outputs-one to the start battery, one to the house battery, and one to the generator battery.
Battery charging duties while underway are handled by two (2) Delco-Remy 105 Amp alternators. These alternators have been modified for external regulation, and are controlled via Balmar MC-614-H regulators. Balancing of regulator outputs is handled via a Balmar Centerfielder. Both alternators charge the house bank, with start battery charging duties handled via a Xantrex Echo Charger off the house bank.
I have read until my teeth bleed any and all documentation I can find on how to properly program these regulators. That programming has resulted in a setup primarily in accordance with Rod Collin’s direction in his most excellent website (https://marinehowto.com/), where he goes into extensive directions, including some video support, on how to program the Balmar 614s.
My conundrum is this. If I read Rod’s directions correctly, he is primarily concerned with making sure my batteries are not driven into “premature floatation” (a low-voltage state, 13.6V for my Fullrivers) underway. His concern is, with a partial SOC after being off-grid, not allowing the alternators to stay at a high voltage state (14.7V for my Fullriver AGMs) long enough will not return the batteries to at least the 80% SOC that seems to be the universal “sweet spot” for off-grid charging in a reasonable amount of time. So, having drunk his Kool Aide, I have dutifully dived into the advanced programming of my regulators, and forced my alternators to stay in absorption for 6 hours. When I’ve been on the hook overnight, and my battery bank is depleted, and I get underway for my next destination, all is well. My alternators put out ~160A for hours on end. And yes, they’re properly de-rated to handle belt loads, and are equipped with both alternator and battery temperature sensors as well.
BUT, on the first leg of my trip, my batteries are at 100% SOC, having been on the shore power battery charger for days at a time. So on my first leg, my alternators are humming along in absorption mode (14.7V), the batteries are fully charged, and their charge acceptance is very low (~1-2A, depending on house loads underway. And I’m sitting aboard, stewing over the fact I’m sitting on about $6K of brand new AGMs, being subjected to a 14.7V charge voltage (albeit at very low current). I simply don’t want to barbeque this new battery bank by misunderstanding the charge regimen I’ve programmed into them.
And it’s my understanding that Rod’s concern for this conundrum is small, as he’s witnessed 99.9% of AGM batteries damaged via undercharging, and virtually none from this overvoltage state.
Anybody else share my concern?
Battery charging duties while dockside is accomplished via a Blue Sea Systems multi-stage 40A “smart” charger. While I recognize this charger is marginal in capacity, I’m assured by Blue Sea that it is up to the task, and will not be overloaded in any way, even while charging such a large house battery bank. It’ll simply take a while! This charger has three charge outputs-one to the start battery, one to the house battery, and one to the generator battery.
Battery charging duties while underway are handled by two (2) Delco-Remy 105 Amp alternators. These alternators have been modified for external regulation, and are controlled via Balmar MC-614-H regulators. Balancing of regulator outputs is handled via a Balmar Centerfielder. Both alternators charge the house bank, with start battery charging duties handled via a Xantrex Echo Charger off the house bank.
I have read until my teeth bleed any and all documentation I can find on how to properly program these regulators. That programming has resulted in a setup primarily in accordance with Rod Collin’s direction in his most excellent website (https://marinehowto.com/), where he goes into extensive directions, including some video support, on how to program the Balmar 614s.
My conundrum is this. If I read Rod’s directions correctly, he is primarily concerned with making sure my batteries are not driven into “premature floatation” (a low-voltage state, 13.6V for my Fullrivers) underway. His concern is, with a partial SOC after being off-grid, not allowing the alternators to stay at a high voltage state (14.7V for my Fullriver AGMs) long enough will not return the batteries to at least the 80% SOC that seems to be the universal “sweet spot” for off-grid charging in a reasonable amount of time. So, having drunk his Kool Aide, I have dutifully dived into the advanced programming of my regulators, and forced my alternators to stay in absorption for 6 hours. When I’ve been on the hook overnight, and my battery bank is depleted, and I get underway for my next destination, all is well. My alternators put out ~160A for hours on end. And yes, they’re properly de-rated to handle belt loads, and are equipped with both alternator and battery temperature sensors as well.
BUT, on the first leg of my trip, my batteries are at 100% SOC, having been on the shore power battery charger for days at a time. So on my first leg, my alternators are humming along in absorption mode (14.7V), the batteries are fully charged, and their charge acceptance is very low (~1-2A, depending on house loads underway. And I’m sitting aboard, stewing over the fact I’m sitting on about $6K of brand new AGMs, being subjected to a 14.7V charge voltage (albeit at very low current). I simply don’t want to barbeque this new battery bank by misunderstanding the charge regimen I’ve programmed into them.
And it’s my understanding that Rod’s concern for this conundrum is small, as he’s witnessed 99.9% of AGM batteries damaged via undercharging, and virtually none from this overvoltage state.
Anybody else share my concern?