The battery monitor is probably not setup for a charger voltage to be entering from the cigarette lighter. To better establish the actual conditions of your setup you need to provide the terminal voltage of each of the batteries. You also need to provide the chemistry of each of the batteries.
A flooded lead acid battery that is drained ~90% will read ~12.65v with no load after 24 hours of being disconnected from the circuit (physically remove the ground connection from the battery terminal). Anything more than 12.65v after 24hours of being disconnected tells me the monitor is wrong. This is what I would look for to confirm that the battery monitor is indicating true state of charger. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Mon, Nov 23, 2020, 21:50 Charlie Nelson via CnC-List < cnc-list@cnc-list.com> wrote: > My boat has a house bank and a starting battery with an ACR controller so > that the ‘banks’ are ‘equalized’ when a charging source is available—shore > power or engine alternator. > > I added a solar panel to maintain the batteries without the hazards of > leaving the boat on shore power charging when I am not on board. > > Per local advice, I ran the solar power output controller (MPPT) current > thru my cigarette lighter(with the appropriate circuit breaker in the ‘on’ > position) and it appears to be working since my house bank (which powers > the cigarette lighter) looks like it is 100% charged per my Victron battery > monitor after 9 days without a battery charger or running the engine. > > OTOH, my starting battery voltage sagged over these 9 days of this test to > about 90% of maximum per the Victron battery monitor. > > My understanding of the ACR is that it should distribute charging current > to keep both battery banks ‘equalized’ so the lower charge state on the > starting battery doesn’t make sense to me. > > My questions to the list are: > > 1. Should the ACR be equalizing the charging source current as I discuss > above, even when this current might be significantly less than my shore > power Xantex 40? > > 2. If so, why is my starting battery ‘down’? > > 3. If not, what am I doing wrong? I could hook up the solar directly to > the starting battery but with the ACR, this seemed unnecessary (if I > understand how an ACR works.) > > Charlie Nelson > 1985 C&C 36XL/kcb > Water Phantom > Sent from AOL Mobile Mail > Get the new AOL app: mail.mobile.aol.com > October is the time to show your appreciation with a small contribution to > this list to help offset the costs. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks > - Stu
October is the time to show your appreciation with a small contribution to this list to help offset the costs. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu