Battery charging questions

eric

Well-known member
Joined
Jul 20, 2011
Messages
137
Fluid Motion Model
C-24 C SE
Vessel Name
Sassy Girl
I have the 2010 EC 21. My question is......when boat is running and battery is charging, will it charge the starting battery first and then the house battery? Also same question when using the onboard charger?
When I was out this past weekend I had the anchor light on as I was on the hook. I also fell asleep with radio on.
In morning the battery was dead. But the motor started fine. Last year I used even more load and never ran out. But this past winter I did not have batteries on battery tender.
I think maybe I didnt run enough first day to get house battery up to charge?

Thanks
Eric EC21 Mechanicsburg Pa
 
Both batteries will be charged at the same time whether using the alternator or charger. The alternator should charge the batteries quicker than the charger. The battery that is the "least" discharged will charge to "Full" quicker. The older a battery is, or the more that it is used, the less of a charge it will be able to hold, which explains why your battery runs down quicker. To test the batteries, you should get a battery load tester, which can be obtained at most auto parts stores that sell batteries. It not only tells you the voltage of the battery, but also how much of a load is remaining on the battery. It can also tell you if the alternator/charger is working. I just bought one and used it on my fully charged starter and house batteries. The starter batter looks good, but the house battery is starting to get weak, which is expected.

The factory installs Exide type 24 combination starter/deep cycle batteries on the R21 EC. These are 70 Ah batteries - which is not very much. The combination batteries do not last as long as plain deep cycle batteries. The plain deep cycle batteries can handle more charging cycles than the combination batteries.

The first night I anchored overnight, I anchored about 10 pm and ran the refer all night, and the house battery was able to support it. On my next cruise, I discovered my Garmin 5212 has an Anchor Watch. So I ran the Garmin Anchor Watch and the refer starting about 5 pm, and about 3 am in the morning, the Garmin started beeping to let me know the battery was low. I have another bank of house batteries which are Type 24 12 volt 70 Ah batteries connected in parallel, which gives me 140 Ah, which is not enough to run my inverter and other DC items. I just removed those batteries and installed two Interstate GC2 6 volt 232 Ah batteries, installed in series to give me 12 volts. These batteries are great. They run my inverter/microwave. I am going to move the refer and Garmin over to these batteries, and leave my original house battery for the lights, pumps and radio. The Interstate batteries are deep discharge batteries and should last a lot longer than the combination batteries I was using. The GC2 are golf cart batteries, but Interstate also lists them as RV/marine batteries. Batteries need to be listed as "marine" batteries so they will hold up to all the pounding they can get on a boat.
 
RProffer":omhci52i said:
Both batteries will be charged at the same time whether using the alternator or charger.........

However, this is not true for all R21-ECs, so it is important to check each boat individually. Our 2007 has a shore-power charger which charges only the start battery. I have built a jumper which I use when I know both batteries are "up", i.e. as soon as I get back home from significant use. The jumper is only in place when that is true and I have the shore power connected. It is not used when under power since the battery combiner takes care of keeping both batteries charged when the engine is running. By connecting the positive poles of both batteries (the negatives are already bonded in common) it allows the small charger installed in 2007 to maintain both batteries at peak charge while on shore power.

It doubles as a jumper cable in the event that the start battery happens to die (it happened!) and will allow an emergency start from the house bank (provided it has not just died, too, but one has to be real unlucky for that to happen). It would be handy for this on any boat which is not wired to allow switching batteries at the master switch. Much faster and easier than switching battery cables.

There is a picture in my album at:
gallery2.php?g2_itemId=31089
 
I am sorry. From previous discussions, I thought all tugs had a charger that was capable of charging three banks of batteries.

Eric, If your charger is a ProTech 1220i, then it is capable of charging three banks of batteries. The charger is located under the aft bench seat on the port side, right behind the electrical plug.

I learned many years ago it was good practice to carry a set of jumper cables on my boat. I never knew when I, or someone else, would need a jump start.
 
Thanks all for the information. That answers my questions.
Eric mechanicsburg Pa EC 21 Gentle lady
 
Our 2007 has a Guest ChargePro 2608A-B. Not much of a charger. It is mounted on the battery box under the engine compartment. Single battery charger with a 6 amp output. Not a whole lot better than a trickle charger. It will maintain them both indefinitely using the jumper. But if one of them is down a bit, say, if the instruments are not shut down for a couple hours before installing the jumper, the charger will just kick out with an overload and do nothing.

http://www.marinco.com/product/6-amp-si ... ro-charger

Quite puny, and also quite disappointing. I found out the hard way, of course, by having my house battery go pretty flat while working to document the fuse panel and wiring one weekend. I expected both batteries to be charged as long as shore-power was on. Nope...... I have learned to live with it quite well once I learned it's limitations and how to work around them, but would never replace it with a like unit.

I'm glad they have upgraded the systems on the newer boats.
 
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