Electrical usage and Electrical System summary

When Whisper is away from the dock, we consume between 150 Ah and 250 Ah in a 24 hour period. We probably average around 200 Ah. We would like to be able to replace this every day — quickly, quietly, and reliably. Our solution is a large 12V DC generator to quickly bulk-refill the used amp hours. We have 735 Ah (in our house bank) from seven 105 Ah Toyama Gel-AGM hybrid batteries.

Although we considered wind, solar, AC generators, and large-frame alternators on the main engine, our solution works well for our needs.

Our original DC genset solution was a Fischer Panda AGT 4000 12V DC genset. For the numerous issues we had with the Fischer Panda, see this log — Fischer Panda: Chapter Close. This was a poor and expensive chice for us and it was replaced in 2008. See this log — New Genset Installation for our installation and experience so far.

Batteries

For our cruising house battery bank, we initially installed eight Group 31 Lifeline AGMs in 2001. We replaced all of our perfectly good factory installed Trojan flooded cells thinking the AGMs would provide faster charging, easier maintenance, more reliability, and better overall deep cycling performance. We allocated seven of these (105Ah each)to the house bank (735Ah total) and one dedicated as the engine start battery (105Ah). The seven AGM's fit in the existing battery boxes, and the single start battery was installed on a new shelf in the engine room.

In less than two years of 25-30% daily discharging, these Lifelines were completely shot. None of the individual eight batteries could hold a charge. After months working with Lifeline on back-and-forth diagnostics, discharge testing, equalizing, and red-herring investigations on our charging systems, we came to the conclusion that these particular batteries never would never live up to their specifications or our expectations. We limped across the Pacific with an ineffective battery bank of less than 100Ah available capacity, knowing we would need to replace them all before heading out cruising again.

In 2007, after two years sitting (mostly) plugged-in to shore-power at the Bayswater Marina dock, we replaced batteries in preparation for 2008 cruising. After discussing with Enertec Services in Auckland, we settled on some Chinese-made Toyama Gel-AGM hybrid batteries. These had a decent performance specifications and were reasonably priced. They don't carry a "name brand", but so far, they have lived up to their performance specs and their charge, discharge, and cycle performance curves almost exactly. Accurate and realistic performance claims. Reasonable price. So far, we are VERY happy with these batteries. The batteries seem to be performing very well after almost a year of mixed-intensity use and five months of intensive use. Lifeline had always blamed our charging systems for their battery's poor charge-holding performance. Poppycock!

Battery Charging

Our DC generator

We have recently acquired a replacement genset, an OnSite Power Systems (Australia) DCGen 482M-12/200 sold to us through Power Stream, Australia. The DCGen 482M-12 specs can be found here for the 100 Amp model (we ordered the 200 Amp model). It is a simply engineered DC Genset that delivers about 180 amps (hot) directly into our 735 Ah house battery bank. We received and installed it in March and April 2008 and tested it out in the Bay of Islands in early April. See the New Genset Installation log for our installation and experience so far.

The DCGen 482M-12/200 is simply a marinized 2-cyl Kubota 482 engine direct driving (via spider coupling) a 200 Amp Prestolite 4860RJ (off-the-shelf) alternator. It can pump up to 14.7 Volts through our MC-412 Balmar Voltage Regulator. The Kubota runs at a fixed 2900 RPMs, has decent fuel efficiency, and should recharge our batteries in less than two hours of runtime a day (supplemented by about 40 to 80 Ah of daily solar panel contribution). The DCGen cooling system is now plumbed through our hot water heater. See the section on Water and Watermaking for more information on how we now heat water.

Although the DCGen has a sound shield option, we wanted to try this solution without one. It's a larger engine and a standard alternator (no fancy engineering to make it tiny), so even without the sound shield it will take more space up in the engine room. Sans sound shield, hearing and/or spotting any problems should be much easier, but in theory, we won't have as many problems with the new genset because it's so darn simple! Of course, it will be much louder than the old Fischer Panda. This is just another compromise we will make in favor of simplicity, reliability, and maintainability. Time (and experience with the DCGen) will tell if this was a good decision.

One cool aspect of the new solution is a provision to mount additional belt driven accessories off the DCGen frame. Refrigeration compressors, high-pressure watermaker pumps, and Bauer dive compressors are all available options. Although we didn't go for the model that has these options, we still get the frame mount point for a water/hydraulic pump or fridge compressor. By adding a hydraulic pump and remote hydraulic motor at a later date, we could add a dive compressor in the cockpit lazarette (just above the engine room and right next to the four dive tanks). Very cool, but we will wait to do this until we're sure we are happy with this solution.

Xantrex ProSine 2500: AC Inverter/Charger combo

For shore-side charging and 120V power inversion, we went with the Xantrex ProSine 2500W Inverter/Charger. The inverter transforms 12V DC to 120V AC with a loss of only a few amps. It also contains a 100 Amp 3-stage battery charger for shore powered charging. From what we hear about this particular ProSine 2500 unit from other cruisers, we are very lucky — this unit has lasted eight years without failing once. Touch wood.

For 240V AC 50 hz shore power, we drive the input 240 volts through a 2500 watt TSL Isolating step-down Transformer (manufactured in Auckland, New Zealand). From there, the 120V AC out of the transformer it goes directly to the 120V inverter/charger (for isolation and fast inverter switching in the event of a power cut) then to the main circuit breaker for the power outlets and the water heater. Whisper is now wired for 240V AC input and all 120V AC on the inside. Someday we may add a 240V outlet inside for a space-heater or a dehumidifier.

As of January 2008, our only complaint with this older ProSine 2500 unit is the inverter (when on) consumes 4-5 amps all by itself without any AC load on it. This is a waste. The newer ProSine units allegedly don't do that, but it's worth asking. Another minor issue is the vendor never updated the firmware for the Advanced Control System, and therefore never really supported a true AGM charging profile (Xantrex said just default to "flooded"). According to Lifeline, this may have helped to prematurely kill our Lifeline AGMs (but we doubt it because the new Toyama AGM-Gel hybrid batteries seem very happy with their 13.4V float). In addition, it would be nice to have more control over any default charging profiles, as well as to have computer integrated monitoring, alerts, and configuration. I think some newer units may have this via USB or Serial ports. If Xantrex doesn't have this, maybe Mastervolt or Victron Energy does?

Balmar Alternator on the main engine

Before leaving San Diego in October 2002, Shea Weston installed a new Balmar 75 Amp Marine Alternator on the Volvo auxiliary engine. This heavy duty marine alternator replaced the small 50 amp Volvo alternator that came with the engine. Shea also installed a Balmar MaxCharge MC-412 3-stage voltage regulator, a Heart Interface Echo Charger, a House/Start battery jumper switch, and new Tachometer to work with the new Balmar alternator. We also have another spare Balmar alternator and voltage regulator ready for quick replacement mounting.

This alternator is our main charging source on Whisper when the DC genset is down or when underway motoring or motor-sailing. It has been tough and reliable and the spare alternator and regulator are still sitting unused in the parts cabinet good-as-new (update March 2008: decided to use the spare MC-412 on the new DCGen genset, will purchase a new Balmar ARS-5 as a spare to work with either the genset or the main engine).

One small suggestion for improvement (if Balmar doesn't already have this) — Duncan recommends integrating computer software configuration with the Balmar regulators. The current method of programming the regulator (via a tiny binary magnetic switch activated with a special magnetic-tool and programmed with a series of colored LEDs) is just too tedious and well, so 1968. They really need to make this more user friendly and intuitive.

Charging the Engine Start Battery

To charge the engine start battery and keep it isolated from the house bank, we have a Heart Interface Echo Charger installed. The Echo Charger follows the charge curve of the house bank and charges the start battery along the house bank charge profile. Unfortunately, this may not optimally manage the start battery -- there is no way to configure the max charge voltage of about 14.2V on this unit. As a result, the start battery, which requires 14.6V to 14.9V bulk (we do 14.7V at 77 degrees F), may be perennially undercharged. Occasionally, Duncan combines the banks with a manual switch to give the start battery a full charge combined with the house batteries at 14.7V.

Battery Monitoring

We have a Heart Interface Link 20 battery monitor. The display is great, but the set-up process is a bit too tedious for Duncan's taste. Ideally, a latest-greatest monitoring solution would be a stand-alone device like the Link 20, that is optionally computer integrated. It would have the normal digital and "dashboard light" read-outs and would be fully configurable via very-user-friendly software. It also would keep a downloaded and synchronized log of every charge and discharge cycle over the lifetime of the batteries and provide alerts for anything behaving outside user specified parameters. It could also be used as evidence to help get your money back from Lifeline if they insist your charging regime is what killed your batteries.