R-21 EC Battery Trickle Charger Recommendations?

[RoverKate]

I'm in my first year of R-21 EC ownership (also first-time boat owner), and trying to solve a parasitic battery issue. When I left the boat on a mooring for 2 weeks, battery #2 (house battery) would always be predictably dead. Yes, I made sure the 2 main switches were OFF in the cabin. Battery #1 (starter and bilge pump) was reliable. I even removed the refrigerator fuse, but still the house battery would be dead each time.

Any beginner-level ideas on resolving this? Trickle charger--any specific suggestions, like a solar one? Or any specific ways to trouble-shoot--I have no experience here, so be merciful to this newbie.

 

[bob daily]

Check the radio in the cabin, it draws power from the house battery for the memory and draws power directly from the house battery (no switch to turn off)
Bob

 

[SKing]

Once you have drained an AGM battery dead you will continue to have problems with the battery regardless. Read articles on AGM batteries to gain more knowledge. You'll learn that you should only draw one down by 50% in order to extend its life.

Installing a battery shunt would provide you more information. You will always know how much draw is occureing. Also you would be able to determine how far the battery is able to draw down. For example if the battery can only draw down 20 amps before the voltage dips significantly you know it's time to change the battery.

If you don't have a shunt installed so that you can see what is happening, you can do the same thing with a good quality meter. After turning off all the items associated with the house battery, lift the battery post and insert your meter between the battery terminal and the removed lead. Do this with the meter is set up to read amps. You can then monitor how much amp draw you have and continue to troubleshoot and see what causes the power draw.

Once you know the amp draw of the final items that you will not be disconnecting, you can use Simple Math to determine how many hours before your battery is completely drained.

If it was my boat time and money. I would install the victron shunt first. Use the information that I gather to understand what is drawing power and how to shut things off. And only after I figure that out on my old battery would I change to a new battery. Because I wouldn't want to waste the money and destroy a new battery.

 

[Newf]

There are lots of good videos online on how to check your battery for a parasitic draw with a simple multimeter. You can also do a load test using a multimeter or take it out and have it tested at a battery shop. If it's a lead acid battery you can check for dead or weak cells using a hydrometer. What type of batteries do you have and how old are they? On my 2014 I still have the same house battery and replaced my start battery only last year. (No overnight draws on my batteries other than the radio memory as Bob has already mentioned) Note: On mine the bilge pump is hooked to the house battery.. Most but not all folks believe that there should be nothing hooked to the start battery that's not associated with starting the engine.

 

[ohioan55]

I agree with what Newf says about moving the bilge pump to the house battery. Remember that if you have a lot of rain and no cover on the back, that bilge pump will run. Here's an example: I went to look at a R-21 in Rock Hall MD some years ago. I met the owner on the dock. We went down to the boat to find that water was ankle deep in the cockpit. The fellow was older, so I got on the boat to examine things. He said that they had a lot of rain lately. The boat was plugged into a receptacle on the pier, but someone had killed power to the pier. I tried to start the boat, but the start battery was dead. I didn't go further, but I did turn power back on to his boat and left. Since that experience, on our 21, I made sure the primary bilge was on the house battery, and I added a second pump forward on the engine and powered it off of the AC batteries. As a thought, the boat that I looked at also had more than ankle deep water inside the pilot house, which could lead to mold problems down the road.

 

[ohioan55]

I'm in my first year of R-21 EC ownership (also first-time boat owner), and trying to solve a parasitic battery issue. When I left the boat on a mooring for 2 weeks, battery #2 (house battery) would always be predictably dead. Yes, I made sure the 2 main switches were OFF in the cabin. Battery #1 (starter and bilge pump) was reliable. I even removed the refrigerator fuse, but still the house battery would be dead each time.

Any beginner-level ideas on resolving this? Trickle charger--any specific suggestions, like a solar one? Or any specific ways to trouble-shoot--I have no experience here, so be merciful to this newbie.

As for a charger, you could mount a panel on the rear swim platform railing. A 150watt model would be more than enough to keep batteries topped.