Battery question

[talbot]

The 12v battery that drives our electric motor, GPS, and nav lights was almost dead when we got back to the dock several nights ago. I didn't think I had been using the motor more than usual, and the solar charge indicator came on in the morning. But I pulled the battery and brought it home to change on my bench. It took all day on the 2-amp setting to get up to a charge of 13.3 v. At that point the charger said it was done. My sailboat electronics book said to wait a few hours, after which the voltage should rise about .1v. It didn't. The next morning it had dropped to 13.0v. Is these typical voltages? It's a series 22 AGM battery, 970 Reserve minutes, 600-something cold-cranking amps, I think rated for about 400 cycles. The battery is several years old. It gets used heavily a few times a year, and the rest of the time mostly serves as ballast.

[GreenLake]

There have been recent articles in the sailing press on how to charge or not to charge AGM batteries. The upshot was that incorrect charging can damage these batteries. With luck you might find some material online. I use more traditional deep cycle batteries, and they tend to last me about 7 years, although the last crop seems ready to push beyond that.

[talbot]

Seems like I'm OK. 12.6v-13v is a commonly recommended state of charge for AGM batteries.
I don't seem to have made any errors in charging protocol (the battery lives on a solar trickle charger with charge controller).
I apparently just used the motor more than I realized and ran it down faster than the solar panel could replace.
Part of the problem is the distance between the battery installation forward of the CB and the motor outlet near the stern. I used the largest cable that the outlet would accept (6AWG), but I'm sure I suffer a large voltage drop over that long run.
I also wonder about the Minn Kota wiring between the plug and the motor inself. The gauge seems small, and the wire gets hot in use, as if it can't really accommodate the 30amp load.
With the gas outboard on the boat now and no pending trips that require running lights or GPS, I may just go without the battery for a while. Give us all a chance to recharge.

[GreenLake]

I went to something like AWG 0 when I did my "extension cord" for the MinnKota. It's much heavier than what they were using. I couldn't find any inline couplers to handle the difference in gauge so I used crimp on eye terminals with a screw-on terminal block. Inelegant but workable. Originally, the idea had been to mount the extension part permanently and terminate it in a plug. I was going to fit the plug by cutting the original wires on the motor and connecting them again by the plug, because, as you write, they don't accept very large wires.

However, right before I finally did the upgrade, one end of the motor cables melted where it was connected to the battery, so I decided that the convenience wasn't worth adding more connections and, in the case of a plug, the risk of a bad connection (which would heat up even faster than the wire).

I also found my extension rather heavy for something to be permanently added to the boat and as I use the motor less than half the number of times I bother to bring it, I can live with not having a "quick" connect.

I'm glad you've discovered your batteries aren't damaged, after all.

[talbot]

Well, that's scary, burning up a motor cable. Anyone else have issues with Minn Kota wiring not handling the current required? It's ironic to have gone through a lot of hassle to buy top-grade cabling and run in through a breaker and fire-resistant conduit, and then have the appliance itself fry at the end of the circuit. 'This was a freebie motor; I'm unlikely to put any more effort into it. But I wonder if anyone else has tried to upgrade the cable or found other brands that use thicker wire.

[GreenLake]

To be fair to MinnKota, this happened at the connection of the original cable to the battery. It looked solid, but apparently wasn't, and started to smoke. It appears not all battery terminal posts allow solid contact to the simple eye fittings, because on some the screws don't tighten all the way. But this was a good reminder to not introduce any unnecessary couplings to the system.

Now, I connect the eye terminals from the larger gauge wires to the battery. They are thicker, which reduces the problem. At the currents involved it takes very little voltage drop to cause a connection to heat up. I certainly did not notice it in the way the motor performed, only when I smelled the smoke.

[powpowhunter]

I burnt up some wiring last week. Was motoring away from the launch through some pretty nasty weeds, which I think put a pretty high load on the motor. Was running the 30 lb motor full tilt trying to dodge the weed cutter boats as they were coming in. Very big and sharp chunks of metal. Smelled something nasty and saw smoke curling up out of the rear junction box. Killed the master switch immediately, and was able to paddle out past the weed cutters and get up the sails to get out of the way. Luckily the wind held until evening and I had a pleasant sail for the rest of the day. When I got home and opened up the junction box, it was the negative wire on the light socket that had burnt up, not the motor wires. I think the light socket shorted from moisture, and maybe the junction from the negative leads on both the trolling motor and light socket to the 6ga neg return to the battery was not tight. Also, I did not have adequate fusing. So, now I've rewired everything. Dropped from a 60 to 50 amp breaker at the positive lead of the battery, and another 50 amp in the rear junction box, which makes a nice junction using ring terminals to go from the 6ga extension to the much smaller motor and light leads. Also the light socket got it's own 4amp fuse in the rear junction box. I've made a better connection on the negative side, but I still haven't figured out the best way to go from the 12/14 gauge fixture wires to the 6ga jumper cable. Right now I'm using a twist lock connector. Have used this rewired system twice now and so far so good, but I'm still a little leery. I think a small fire extinguisher might go on board...

[talbot]

Tell us more about the geometry. Where is your battery mounted? Where did you put the main breaker?
What is the light socket you mention: Is this a running light, like a red/green/white all-around?

Good point about burning things up because of connections (i.e., you can do everything by the book in terms of gauge, materials, etc., but if you don't maintain them, you can still have problems.) I never thought of a fire extinguisher before I got a gas motor. Now I see it might be a good precaution with the electric as well. FYI, I put mine in the lazarette, aka cooler, on my DS II. (I never use it as a cooler.) It rattled around loose in there for a year before I installed the mount. Much quieter.

[powpowhunter]

First off, credit where credit is due- The DaySailer.org community. Thank you all. Pouring over threads here has been foundational from buying my boat to learning how to sail her. This project was no different.

The battery is mounted to the base of the mast/compression post (hinged mast) with U-bolts. I used the biggest washers I could find as backing plates inside of the box. The battery strap is run through a mast-side plate for each u-bolt. Because I was worried about torque on the mast from the battery, there are 2 full length industrial velcro straps adhered to the box and floor underneath. I can't budge it. Not sure how it would fare in a capsize, but I put the boat on edge with this set-up and though it was not my focus at that time, nothing shifted during that ordeal. The red master switch is mounted through the battery box lid and just glued in place.

Inside the box the 50 amp breaker is installed close to + terminal, before the master switch. Wiring is 6ga jumper cable with ring terminals bashed on. Taking off from the master is 6ga to the rear junction box (through conduit) and 12 ga goes to the front switch box terminal bar, which currently only runs the front nav-lights, but has 2 extra switches/terminals for the future (probably a 12-volt socket for tunes/GPS at some point and I don't know what else).

Rear juntion is a t-junction box, velcroed in place, with trolling motor plug socket to the side, and light pole socket on top.

6ga jumper cable terminates with ring to another 50 amp breaker from which takes off trolling plug wiring and fuse holder for 4 amp mini(atc) fuse to light socket. Crammed in there is red twist lock junction for negative leads.

[powpowhunter]

The rear light is an all round white on 4ft? pole base that goes into the socket. Luckily the boom just clears it. I wish I could find an affordable tri-color light for the masthead. Those suckers are expensive, and likely way too big for a DS anyway. Something like a Navisafe tricolor (http://www.navisafe.com/project/navi-li ... lor-2nm-2/) but wired for 12v and a remote switch would be a perfect masthead for our boats. So much so that I've actually contemplated contacting the company and suggesting such a thing. Motor is 30lb minnkota with kipawa prop.

For sailing, I used the packaging the light came in to build a shade that (very very approximately) blocks out the forward 225 degree arc. For steaming (trolling) or at anchor I just slide the cover down.

[powpowhunter]

What kind of solar panel and charge controller are you running Talbot?
I'm thinking of adding that to my system for battery maintenance. I was thinking these would work well:
http://smile.amazon.com/gp/product/B007 ... UFSIGRIGBC
http://smile.amazon.com/gp/product/B000 ... 76PZNDKUUJ

Also, anyone please feel free to critique and find the flaws in my wiring set-up. I really don't want my boat to end up a molten plastic slag puddle in the lake.
I'm very much a Red Green type of handyman (including the not-handsome bit). Keep your stick on the ice!

[TIM WEBB]

That, sir, is one very elegant setup! Although I switched from troller to gas motor, I still have a 12v system setup on TRW, for other things such as you mention like tunes, charging things, 12v stove, etc. I'm just using the Attwood battery powered LED nav lights, as I don't need/use them enough to warrant standing wiring.

For multi-day trips, I can tell you that at least down here in the little latitudes, the PowerFilm solar panel/Sunguard charger work just fine to keep the battery topped off. I went with the R14, just because it fits nicely across the seats in the stern, where it gets the most sun during a day of sailing. I put snaps on the panel grommets and snads on the seats to hold it in place.

One question: your boom clears that stern light?! How high is the rig on your boat? TRW's boom would barely clear the mast support shown. Could be the angle/focal length of the pic tho ... ?

Love the Red Green reference - that guy is hilarious! That show had such a "Monty Python" feel to it ... who wouldn't laff? ;-P

[powpowhunter]

Thanks Tim. As I said previously, almost everything in this design I cribbed from someone else on here who came up with it first, maybe even you?
I use the atwood battery lights on my little tin can fishing boat, even though it's got a starter battery in it. They're cheaper than a 12v system and work really well. I love sailing at sunset though (viewtopic.php?f=8&t=4810), and figure if I was already going to run the wiring for the trolling motor, may as well do the lights too.
The Powerfilm R13 is apparently akin to a factory second R14. Dimensions are similar and wattage is (perhaps) only slightly less. The first comment on the product from Amazon is enlightening: "Simple put the R-13 at $125 dollars is a bargin when compared the the other versions such as the R-7, R-14, R-21 and the R-28. Do a search on the prices and you will agree. You basically get a R-14 for less than the price of the R-7. You could buy 2 and connect them together and have 26 watts, a little less than the R-28 , and you still save some money.
I attempted to find some info on the R-13 on the internet but I could not. I contacted the good folks at PowerFilm to find out is this a new product or a obsolete one, turns out it is neither. Basically when they have extra matterial left over from a production run they use it to make the R-13. So they make some, put them on Amazon, sell them. And then latter when they have some more they do it all over. So basically they are not available all the time!
15.4 operating voltage, 13 watts. When I tested it connected directly to a 18 ah battery I measured 823 milliamps current.
So if you want a good product and want to save some money, hurry while they still have them available."

I've been watching for a while and it seems like they put up a few 'factory second' R13s every couple of months or so. I think I'll wait until next summer to bite that bullet though.

The light pole does rake back slightly. In that last picture of the light in my post, showing the cover, I held the camera pretty well vertical, so the angle of the pole apparent there is real. There is probably no more than 2 inches of clearance- horizontally. The light is above the boom, but the boom is not long enough to hit it. I didn't know how that was going to work out- I kept the receipt when I bought the light. Just got lucky.
I'll try to remember to take a picture next time I have the mast up. But, fair warning, I will probably forget to do so. When the mast is up, the boom on, and topping lift tied, taking photos seems to be far from my mind...

[talbot]

Very professional setup.
In answer to your question, I'm using a Sunforce 5w trickle charger. OK, but not marine wire (non-tinned). Not sure how long it would work in a saltwater environment. Because where I live, saltwater=tides&currents, I don't use the little 30lb Minn Kota at the coast, so all the 12v system powers there is the forward nav lights, GPS, and compass light. I was wiring-weary by the time I got my AWG 6 to the stern, so my white light is a portable that runs off 4 AA cells. At anchor, I attach it to my topping lift (lazy jacks support the boom) and run it to the top of the mast.

Question: I assume those jumper cables aren't tinned copper. Are you sailing on fresh water?

Good idea for blocking the light forward. I use a piece of foil-backed high-temp tape on the lens itself to block the light, but of course I have to remove it to use the same fixture as a 360 masthead light. And then re-tape it for the next night. I have not spent more than one night aboard at a time, and those trips have been weeks apart, so I haven't had to really address the awkwardness of my system.

Now I'm pondering a shut-off switch. I'm depending entirely on my breaker. My battery is mounted about where yours is, but below the cuddy floor and on the aft side of the mast (under the CB controls). My breaker and charge controllers are mounted to the mast inside the cuddy. But, yeah--if something caught on fire and the breaker didn't throw, I have no way to isolate the battery. Hm . . . . .

Another cautionary tale: My forward Attwood nav lights are mounted on the cuddy sides, something I copied from larger boats I've seen. Very easy to wire and service. I love not having to climb out on the bow to screw on the portable lights. I've gotten compliments on the Attwoods . . . but not from anyone who has sailed with me at night. On larger boats, those lights are 20' away from the helm and out of sight. On the little DS, they reflect off the deck and absolutely ruin the night vision of anyone in the cockpit. Trying to bring the boat into coves at night, I have had to turn them off to see anything beyond the edge of the deck. Where did you install your nav lights? Greenlake (moderater of this forum) put his combo light on a little wood platform that extends off the prow. I'm considering reinstalling my lights on the hull close under the curly hull/deck connection. I would have to run wire through the front bulkhead, cut holes in the hull, and reglass the holes in the cuddy. But until I make some change, the lights are an aesthetic accoutrement and a navigational hazard.

[powpowhunter]

No, the jumper cables are not tinned. I need to buy a tube of dielectric grease to slather on the rear twist lock connection so it doesn't corrode. That is most vulnerable and weakest link in my setup. I'm a long way from any saltwater though, and I doubt this boat will ever see a tide.

Currently, I have a combination nav light mounted centerline on the forward peak of the cuddy roof. It is not an ideal spot. The jib partially blocks the leeward light. However, that lights up the jib sail which I think helps to be seen and identified as a sailboat, which is really what I'm going for. The light doesn't shine off the deck too terribly and doesn't interfere with vision where I sail. But where I sail there are plenty of city lights and the boatramps are well lit and the channels marked. On a truly dark night and in treacherous waters the lights might interfere.