New batteries

[Mike Brown]

After having the one year old Deka 4Ds for our house bank fail to prove enough ooomph while on the hook I decided to replace them with 4 Trojan T105s. I checked Specific Gravity and both were marginal at best. Also did a load test by fully charging them and then throwing apx 24A load on them. It only took an hour for them to drop to a 50% level, not a good sign. Not sure exactly why the Dekas failed so soon but I suspect I've been undercharging them and they're badly sulfated. One sign is they never need topping off. The charger is set to the Hot temperature setting which may have contributed to the undercharging. The Xantrex tech suggested I set it back to Warm and keep a close eye on the water levels. I'm trying to find a battery temp monitor but Xantrex doesn't make them anymore so it's hit and miss via web searches and phone calls. I could have equalized them but I didn't feel confident that they'd hold up and I hate to lose any sailing time due to low power. Especially on this energy hog. At any rate I'll be installing the Trojan's ASAP this weekend then off on a weeks vacation alternating between marinas and the hook. The new Amp Hrs will be 450 vs 325 (at best) with the old. Should be a much better situation while off shore power.

[foster]

Hi Mike,

Here are a few pictures of the modification of the whole electrical system. The mastervolts slim batteries fit in the original battery space but brings the capacity to 600AH. Charged by the Mass Combi from shore or the generator.Whisper 3;5

This was the best weight / efficiency ratio after a very in deep study of all solutions.

Denis

[foster]

[Mike Brown]

Denis, very nicely done. I especially like how the batteries fit in the space by the battery charger. The 600ah is impressive too. Did you also replace the engine and bow thruster batteries to match these?

[foster]

No, I left the Yanmar and bowthruster bateries. They are charged either by the alternator (Mastervolt 90A couldn't fit the bigger frame one in) or the original battery cahrger 40A Dolphin) by shore or generator.

We also modified so we could in emergency link the service and Yanmar batteries. I also cary along truck clamps 3m long and a balck and decker starter kit. This can start the Yanmar or the generator.

There's are a lot of batteries and i will replace the by gel or AGM when needed.

The modifications have changed completely the comfort on board for extended cruises out of marinas in the Med. We also have a D60 watermaker. The combination of a small generator, big capacity batteries and an excellent Mass combi 100A/2500W allows a lot of electricity and a quick charge. About 2hours of generator is enough. We do not have air condition or a real freezer but a microwave grill.

[Mike Brown]

You have a very nice setup. What type of batteries did you use? AGM, Gel, Wet? What are the engine and bow thruster types? Did you mix them or are they all the same? Looks like we have the same TV in the same place although I don't have the chart plotter connected to it.

[James Taylor]

I agree with Mike. A very nice setup Foster!!!
We have 400ahrs worth of AGM's. So far so good but you have to really watch the freezer usage on anchor. We carry a honda portable generator in case its needed but a marine generator is a much better option. 600ahrs is fantastic and in such a small space! Very nicely done. Looks like those batteries were designed to go into that space.

James

[Mike Brown]

James your right on the money about the freeze usage while on the hook. I spent quite a bit if time on Saturday monitoring the cycle of the compressors for both the freezer and fridge. Each cycles on for 2 minutes then off for 2 mins. Each is independant of the other so at times both are on the amp draw is in the 7 to 8 range. Other times they're both off and draw is nothing. Overall it looks like the avg total hourly draw for both is 3.5 amps. I'll know more once I get the new batteries installed. I'll monitor the batteries and note what's on so I can build a table of power usage.

[sam]

Mike, I went with Lifeline AGM's. Used 6 volts in series. I installed two in the space near the isolators, two on centerline behind the engine, and two in the port lazerette for a total of 660 amp hours. I agree exactly with your observed amp draws for the freezer refrigerator. The new alternator and external regulator charge the system well.
Sam
LONGHAWK, B43 #9

[Mike Brown]

Sam I thought of going with 3 sets but for our present needs think it would be overkill. Hopefully I wont regret it.

[James Taylor]

The current setup on our B43 is 80amp alternator, 40 amp charger and 400 amp hours worth of house battery (deep cycle agm's).This is right at the top of being a practical system, in my opinion. If we need more power we will probably replace most of this systems components (new batteries (600amps min) since these are 2 years old and mixing old and new is a no no, 80 to 100ahr battery charger/inverter and 100 amp alternator with external regulator.).
Mike I think you will be okay with the 425ahrs but if you need to go to 600 you may want to take a look at the whole charging system setup and its components to avoid excessively long charging cycles for a larger bank
James

[Mike Brown]

James, I agree. If I go any larger with the house bank then I need to match the charger or I'll just be wasting my time and money. Actually the present factory setup should match my new house bank at 450ah. I hope to get them installed Friday afternoon and test them next week on our trip. I'll have to remember to report back on their performance.

[Mike Brown]

Here's an update on the new Trijan T105s I installed in place of the 2 Deka 4Ds. I got them wired in the night before we left on vacation and so far they're everything I expected them to be. Seem to hold up well and provide the right amount of power for our needs. Which by the way appear to be quite a bit. I've been watching the Victron power monitor and no doubt that these boats are energy hogs.