Brian, While I tend to agree that a cigarette lighter might not be the best solution, I hesitate to say that it won't work. In the case that the solar charge system is intended to be portable, temporary, and easy to deploy quickly it might be a very effective solution. Most cigarette lighter adapters are designed for 10 amps or 120 watts. My 100 watt panel and MPPT control circuit provide about 6amps peak. So you are correct that a smaller gauge wire will reduce the efficiency of charge, but even a 20% reduction still provides 5 amps which should be plenty to keep most battery banks topped up. Charlie did not state the wattage of his system but as long as it isn't more than ~120 watts it should "work".
There is pretty clear evidence that the solar is providing charge through the cigarette lighter since the house battery is taking a charge and staying topped up. However, the line losses might still be causing problems at the ACR. Just for kicks I pulled the blue seas efficiency chart. Assuming that the total length of wire from the battery to the solar was 25 ft for the supply and return (red + black = 50 ft total). A 16 gauge wire would lose 10% voltage at 5amps. That doesn't sound like much but.... https://images.app.goo.gl/FYtVRdaxeLC6MGEn9 My genasun has the following specs. - Bulk Voltage: 14.4V - Absorption Voltage: 14.2V - Absorption Time: 2 hours - Float Voltage: 13.8V The Blue Seas ACR has the following specs. Combine 30 sec 13.6V @ 12 V Combine 90 sec 13.0V @ 12 V If the charge controller was loosing 10% from 14.4v that would leave 13.0v. Just enough to maybe switch the ACR. That assumes that the controller is not reaching absorption or float voltage which is lower. If the MPPT controller is not putting out enough voltage to reach the ACR threshold (or to Brian's point not enough after line loss) then that would certainly explain why the start battery is loosing charge. We really can't tell what is going on until we know more about the battery chemistry and no load terminal voltage. Josh On Tue, Nov 24, 2020, 00:23 Brian Davis <brianwdavis...@gmail.com> wrote: > Josh makes good points. > > Also, wiring the solar through a cigarette lighter port is poor advice. > The gauge of wiring going from it to a house even with an ACR would never > work and only be a trickle charge at best. I'm guessing the cigarette > lighter wiring is probably a 16 guage, right? Thats a problem. > > Think of wiring as being similar to plumbing in regards to pressure. A > very small tube is a small stream of pressure and even after a few days it > would not fill a large tank of water. > > You definitely need to rethink the wiring diagram. If you have one I can > review it. Also, I can send you what I have recently done on my 38 > Landfall. I literally gutted my entire boat and install everything new that > includes 3 battery banks, etc. > > Regards, > Brian > > On Mon, Nov 23, 2020, 10:32 PM Josh Muckley <muckl...@gmail.com> wrote: > >> 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 > > 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
