Difference between revisions of "12 VDC Electrical System Upgrade – Winter 2003"
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==Battery box== | ==Battery box== | ||
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Before installing the batteries I put in vents in the battery box under the seat forward of the sink. I put one near the floor at the starboard end of the forward facing wall of the seat base, and one up near the cushion in the end wall in the center of the boat. With the benefit of hindsight I should have done that the other way round - the inboard one low, and the outboard one high, as that would have left more space for mounting other components in the battery box. The battery box is a double wall formed by the seat base on the outside and the battery box on the inside. I found that a sabre saw would just reach through the two layers and cut both at the same time. Working from the outside, the inside cut was a bit wobbly, but I ignored that. Grilles from West Marine finished the outside cutouts nicely. | Before installing the batteries I put in vents in the battery box under the seat forward of the sink. I put one near the floor at the starboard end of the forward facing wall of the seat base, and one up near the cushion in the end wall in the center of the boat. With the benefit of hindsight I should have done that the other way round - the inboard one low, and the outboard one high, as that would have left more space for mounting other components in the battery box. The battery box is a double wall formed by the seat base on the outside and the battery box on the inside. I found that a sabre saw would just reach through the two layers and cut both at the same time. Working from the outside, the inside cut was a bit wobbly, but I ignored that. Grilles from West Marine finished the outside cutouts nicely. | ||
I put two blocks of 2 inch thick pressure treated wood in the pans at the bottom of the battery box. This made the base just about level. The 4 Trojan golf cart batteries are definitely a snug fit. These are 225 Ah each giving 450 Ah at 12V. There is about ½ inch between each battery, and also between the batteries and the aft wall. Space at the ends (port and starboard) is slightly better, and the forward space is irregular. I slipped ½ x 1 inch or similar pieces of wood into the gaps between the batteries and the walls to maintain what space there is, so that the batteries would have cooling air round them. I was uncertain how to hold them down, but this winter I will attach straps to the battery box walls and stretch them across the batteries in pairs. | I put two blocks of 2 inch thick pressure treated wood in the pans at the bottom of the battery box. This made the base just about level. The 4 Trojan golf cart batteries are definitely a snug fit. These are 225 Ah each giving 450 Ah at 12V. There is about ½ inch between each battery, and also between the batteries and the aft wall. Space at the ends (port and starboard) is slightly better, and the forward space is irregular. I slipped ½ x 1 inch or similar pieces of wood into the gaps between the batteries and the walls to maintain what space there is, so that the batteries would have cooling air round them. I was uncertain how to hold them down, but this winter I will attach straps to the battery box walls and stretch them across the batteries in pairs. | ||
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− | In the battery box, as well as the Link shunt, I installed a switchable circuit breaker (50A) and a 4-fuse panel, both connected to the battery positive. The Link uses two of the fuses, the radio/CD player memory one fuse, leaving one spare. Because my new vent had removed a piece of wall, the circuit breaker had to be squeezed onto the forward wall of the box. It works, it’s not actually untidy, but it would have been better if everything had gone on the inboard wall. | + | In the battery box, as well as the Link shunt, I installed a switchable circuit breaker (50A) and a 4-fuse panel, both connected to the battery positive. The Link uses two of the fuses, the radio/CD player memory one fuse, leaving one spare. Because my new vent had removed a piece of wall, the circuit breaker had to be squeezed onto the forward wall of the box. It works, it’s not actually untidy, but it would have been better if everything had gone on the inboard wall. |
==Link 10 battery monitor== | ==Link 10 battery monitor== |
Revision as of 19:39, 17 January 2009
John Gardner, Seventh Heaven #695 (1988)
Among the many things I did during a busy winter in 2003 was an upgrade of the electrical system. During the inaugural trip of my 1988 boat, #695, at the end of last summer, we ran the fridge to make sure that repairs by the previous owner were effective. For most of the two hour trip we had to run the engine, and then a couple of miles from home, we dropped anchor for a cup of tea and cake (part of my English heritage). When we were ready to make the final leg to the mooring, the engine wouldn’t start, and you’re probably already ahead of me; the fridge had drained the batteries which were selected to “both.” I learned that leaving the system on “both” is a bad idea and that my electric system would not support the more comfortable sailing life that was supposed to come with the change from a Catalina 27 to a 34.
So I needed to upgrade the alternator, upgrade the battery bank, and improve the wiring.
Most of my sailing is weekend sailing in the Chesapeake, with the occasional trips up to a week or so. The boat is kept on a swinging mooring. With fridge, autopilot, nav equipment, radio, lights, and the desire for things like heated hair rollers (not me!), I concluded that my daily power usage could be as high as 100Ah per day. I concluded that despite limited use, the power demand and replenishment situations put me into the serious cruising category for power requirements. The batteries should be 400 Ah.
ContentsAlternator choiceI went round in the same circle many times deciding what alternator to get. I needed at least 75A, I wanted larger, but I was worried about the ability of the fan belt to transmit the power. Every place I looked or asked changed my mind. Suffice it to say that in the end I went with caution and obtained the 75A alternator. There was a little bit of black dust from the alternator belt, so I took a lot of care with alignment. I found that the alternator mounting bracket wouldn’t move quite far enough to give me the accuracy of alignment I wanted. So I removed it from the engine, slotted the holes slightly, and was able to get good alignment. I had the curved, under- the-alternator bracket, but the fan of the new alternator brushed against it. Using two screws I attached a piece of flat steel bar to extend the lower end of the bracket and hammered the ends of the screws over to ensure they couldn’t come undone. I epoxied a wood block to the wall at the back of the cupboard under the sink in the heads and attached the ARS-4 regulator to it. Connection was pretty straight forward following the Balmar instructions, although there was a little confusion because the color coding of the boat’s tachometer wire was not according to the diagram in the engine manual. |
Click to enlarge pictures |