Battery setup on a 23.5

[SFKjeld]

Got my first real look at my new to me 23.5. Batteries were my first concern. A marine battery for the boat, and car battery for the motor. The marine circuits were operational a few weeks ago when I inspected the boat, DOA today. Thinking I need an A/B switch so I can charge both with the motor. Anyone recommend a location for the switch?

 

[centerline]

check out the thread titled "electrical expertise needed"... do some reading of the links posted there by other members and then make a decision based on what you learn.

just adding a switch to cure a symptom, without knowing the actual problem or the options available, may cost you money in the wrong direction.\

if the batts are dead, why not find out what caused the voltage drain?... and if you want to be able to charge both batteries at the same time, why not install a charge relay?

and if you you have a charge relay, such as one talked about in the other thread, and if you repair the problem so you dont have a voltage drain, what will a battery switch do for you?....

 

[Bill Roosa]

Given the small size of the motor a deep cycle will start it fine. I'd recommend two deep cycle and a 3-way switch just off the positive terminals. BOTH for everything except long sails and anchoring overnight (assumes you don't have a big load like a reefer) Then select one or the other so you have a spare for getting the motor started after the sail or in the morning. Identical batteries will last longer in the BOTH configuration, make it easier to charge (no extra equipment or differing chemistries to worry about) and provide for a longer sail without motor before you have to worry about batteries not getting the motor started.
If you have an outboard you will want to figure out if it will even put much of a charge on the batteries ---> deep cycle will help here also as you will need the extra storage to get you back to dock
ie of the motor only put out 4 amps and you have 5 amps of load with the motor off you are not actually charging the batteries while motoring!!!

 

[Crazy Dave Condon]

Thank you Bill for advising a marine battery.

For the battery switches, it is always recommended to shut the engine off when changing that switch; otherwise you can damage the alternator of an outboard. However the newer ones do have built in protection to prevent that from happening, so when you buy a new battery switch, make sure it has that protection. I forget the term it is. So for the older battery switches, turn off your engine before switching the battery selector.

 

[SFKjeld]

Location of the switch

Thanks all. Actually, you have confirmed my inclination. The batteries should be identical and should be deep cycle. Any suggestions as to where to mount the switch itself and perhaps a suggestion for switch type too.

Also, does anyone know what the factory battery set up was for a '95 23.5? Mostly curious how creative the previous owners were. Were they modifying for cost (auto battery) or function?

 

[Bill Roosa]

If you leave it in both or switch from "1" or "2" to both with the engine running you should not have a problem. Even if the 3-way switch had a dead spot between the settings you are not going to be in that position for more than a fraction of a second. If you think about it, the regulator will see no "battery load" and try to maintain a charging voltage so it should ramp down the rotor current to maintain 14ish (whatever it is set for in it's program) even with the batteries disconnected by the 3-way set to OFF. It would take a few minutes for it to "test" the batteries" to determine that the voltage went to 0 when it turned the alternator off. Even then it would only bump up the voltage to 14.9ish to charge the "perceived" dead batteries. The only time when I could see a problem is when you had deeply discharged batteries (10-0%) and the alternator was putting LOTS of amps and you shut that off with the (almost nonexistent these days) dead spot in between the 1-2-both settings. could cause a moderate voltage spike.
For the record, I've changed batteries while the engine was running (good for dead) in cars several times. disconnecting the batteries is not a big a booboo and easily avoided

 

[SFKjeld]

Where is the best deal today on marine batteries? I bought one at Walmart two years ago for my Potter and it was fine, tho no starter requirement. I guess there is a Kirkland battery too? I am in the SF Bay Area. Thanks!

 

[Crazy Dave Condon]

Bill Roosa;

The battery selector I use to buy had quick field disconnect protection in them as some models did not. It is due to the make up of an outboard engine only that switching the selector on a dual battery system, it can destroy the alternator (not sure of the terminology) on those 8 and 9.9 engines that are electric start. I have heard of failures that did occur which is why I do not advocate switching the battery selector on an outboard engine with it running. I am not a mechanic but a little different from a car.

As for batteries, I use to use interstate. As for the location of the switch, in a sense it can be put anywhere but my suggestion is the run of the cables be as short as possible not to mention the expense of copper this day and age. Try to make those cables the same lengths.