battery system upgrade question

[ralphmacey]

I have a 1984 Tartan 3000 with two group 27 batteries. I installed a Xantrex Trucharge 20 battery charger and now I am thinking of what else I should be doing to upgrade the system. I have had several thoughts and I wonder how to priortize them. I don't have refridgeration but I did install radar, autopilot and a chartplotter this year. I intend on mostly day sailing with a trip from Lake Champlain to LI Sound next Spring for some coastal cruising, overnights are a definate possibility.

Some of the questions I have:
1. Should I install a starting battery, and if so any installation advice, and what type of battery. (I believe my battery charger can charge only one type of battery at a time)
2. How do I monitor the charge in the batteries when not on shore power?
3. Should I buy a small gas generator or can I rely on the diesel engine to charge the batteries.
4. Wind generators and solar panels?

So many choices, you can spend a fortune, how do you get what you need for the least cost?

Thanks for your thoughts.

Bud

[MacGyverRI]

Originally Posted by ralphmacey

Some of the questions I have:
1. Should I install a starting battery, and if so any installation advice, and what type of battery. (I believe my battery charger can charge only one type of battery at a time)
2. How do I monitor the charge in the batteries when not on shore power?
3. Should I buy a small gas generator or can I rely on the diesel engine to charge the batteries.
4. Wind generators and solar panels?

1, It's always good to have a sep. starting battery

2, LED meters for deep cycle batteries?

3, I'm going to get this one, 46 lbs., 1000 watts, 120 and 12V connections.
northern tool com , Portable Generator — 1000 Watt, Model# TG1200 $119


4, flip a coin, both are pricey but make sure you have a minimum of 10 amps. output on the solar panels so they will work well.

[GeorgeB]

We added radar and a color chartplotter and I was amazed at their power consumption. It is much greater than a refrigerator. You will want to upgrade your battery system in order to keep up with your electronics. You can gang your two house batteries together and charge them and an isolated start battery from your Truecharge as long as all three are the same type (e.g. all AGM or all gels etc.) They can be of different sizes. What you may find is your underway charging is now woefully inadequate. Consider on getting an externally regulated alternator. You could still get by with a 40 to 55 amp alternator as the magic happens in the regulator. I think that Balmar and Xantrex use the same regulator so you can use either. We installed a Link 1000 to monitor/control our batteries but you could probably get by with a link 10 monitor on your house bank. I found that Jack Rabbit Marine was most helpful when I did my installation.

[blakew1]

Link 10 for monitoring house batteries works very well.

[HoffaLives]

Start with your alternator. With 16-200 Ah already, you should have a ~ 85 amp alternator with external regulator. Throw in a cheap costco starting battery. Adjust your power switch so you switch the output of the batteries, not the charge input. Keep all leads direct and simple and heavy gauge.

Solar and wind are only adjuncts to your power budget and shouldn't be considered as a major source of charge power. Generator probably most effective/less expensive option. Bear in mind the bigger the alternator (within reason) the faster it will be able to recharge the batteries, to the limit of the batteries themselves.

Also realise that with the Ahr capacity you have listed, you actually only have maybe 50-75 Ahr to play with. That's not a lot. You could be down to 50% in a few hours.

The Link system is an awesome battery monitor/charger.

I don't think there really is a cheap way to have lots of power aboard when sailing or on the hook. Who wants a generator running while they're sailing?

Calculate your power budget, lights, electronics, radios etc. and you will quickly see that everything needs power and it climbs fast. You need good battery capacity to keep it all going and a good charging/regulation system to keep it healthy and charged.

Whenever a guy buys new electronics for the boat it's very important to add the cost of increased power capacity that will be needed to let it run. The greater the power draw, the more the item will actually cost you in the end.

[jwms]

1981 C&C 34, Pacific Northwest.

Just removed two group 29 deep cycle batteries (90ah each), one starting, one house, and replaced them with an AGM 8D for house (250ah) and an AGM group 24 for starting (Yanmar 3GM). Very happy so far.

Using a Guest 10 amp charger now but thinking of the Truecharge 20. My DC demands are pretty light.

No refrigeration, no water system, no radar, but do have an autopilot (~1.5 amps), laptop (~1 amp), TV/DVD (~2 amps), and an Espar heater (20 amps to start, 2 amps to run). All lighting is LED which has an insignificant draw even with all lights on. All of this worked okay with the old batteries but I wanted more capacity.

Have 40 watts of solar panels and this keeps up pretty good when the sun shines. If it's cold out the heater gets ahead of the solar panels because it's also usually not sunny either.

Installed a Microlog battery monitor from SailorsSolutions.com. Very happy with it. You can monitor the charge current and discharge current simultaneously along with the voltage on two batteries. It also has an alarm for low battery voltage but the set-point is not adjustable.

[k1vsk]

Above is good advice except I would question why someone's view that radar/charplotter consumption seem excessive - should only be a few amps most.
Figure out what your avg daily power consumption is.
Size the house battery bank accordingly so as to not consume more than 50% of it between recharges.
For recharging, use above to calc est recharge time for a decent alt/regulator setup and replace both.
Stay away from the cheap portable gensets - either Yamaha or Honda make quality productsl the rest have poor reputations.
Install at Link10 if you want a battery monitor or simply use the voltmeter for gross estimates of charge state
Solar panels should be sized similar to what you figured above for daily consumption as you don't want to continually underchage the bank

[GeorgeB]

It all adds up. If you want an eye-opener, do an energy audit. This is what I’m looking at:

E80 chartplotter - 1.7amps
RD218 RADAR Scanner - 2.3amps
Miltech AIS - .5amp
ICOM 602 VHF - .5amp
Instruments - 1.2amps
Autohelm (avg) - 1amp
Running Lights - 1.5amps
Total - 8.7amps

My refrig cycles at 5.5 amps but runs less than half the time so for comparison purposes it averages 2.5 amps.

Now assume that I also have a red light or two on down below and we’re listening to the CD player to break the monotony, and you can see that I’m burning close to 100 amps while sailing overnight. My trusty Link 1000 has confirmed all of this. The important thing ito remember is you are burning way more energy than you realize and a monitor that can read amps is essential when you are running a big electronics package like I am.

[sailingdog]

I think your house bank is probably a bit on the small side, given that you have radar, autopilot and chartplotter. If you're planning on adding a stereo, laptop or refrigerator....you'll definitely want a bigger bank.

I would add a starting battery and a BlueSea Dual Circuit Plus battery switch. This switch isolates the house and starting sides normally, but allows you to combine the two banks if needed to start the engine. BTW, it is available in a combo package with an ACR battery combiner. This would allow you to charge both battery banks while leaving the banks isolated in normal use. The ACR will detect charging level voltage on either side—charging both banks if either bank has a charging source.

BTW, the Xantrex TrueCharge 20+ can charge three battery banks. However, all three banks need to be of the same chemical makeup...ie all should be wetcell or agm...don't mix types. Even if it couldn't, the ACR would allow you to charge both banks with a single charger—but also allows the alternator to charge both banks while not needing the battery switch in the combine position.

A small gas generator isn't a bad alternate charging source, and far better than running the inboard diesel under a light load. You might want to look at a wind gen or solar panels if you're going to be at anchor a lot.

[JohnRPollard]

Originally Posted by ralphmacey

I have a 1984 Tartan 3000 with two group 27 batteries. I installed a Xantrex Trucharge 20 battery charger and now I am thinking of what else I should be doing to upgrade the system. I have had several thoughts and I wonder how to priortize them. I don't have refridgeration but I did install radar, autopilot and a chartplotter this year. I intend on mostly day sailing with a trip from Lake Champlain to LI Sound next Spring for some coastal cruising, overnights are a definate possibility.

Some of the questions I have:
1. Should I install a starting battery, and if so any installation advice, and what type of battery. (I believe my battery charger can charge only one type of battery at a time)
2. How do I monitor the charge in the batteries when not on shore power?
3. Should I buy a small gas generator or can I rely on the diesel engine to charge the batteries.
4. Wind generators and solar panels?

So many choices, you can spend a fortune, how do you get what you need for the least cost?

Thanks for your thoughts.

Bud

You've already made a good upgrade by adding the TrueCharge. I agree, your current battery bank is a bit on the small size, but not desperately so for how/where you plan to sail. My approach to upgrades like this is to replace components as they fail or reach the end of their useful life, rather than throwing away equipment that still works fine. This is what I'd do in your shoes, in this order:

1) Swap your Group 27 batteries for Group 31s, preferably AGMs. The 31s fit in the same battery box as the 27s, but you'll immediately have 25-35 more reserve ah. But I wouldn't do that until the Group 27s began showing signs of anemia. OR, explore the possibility of even larger batteries if space permits, but be mindful of weight and trim issues.

2) Upgrade your alternator to a higher output Balmar or equivalent with smart external regulator (e.g., MC-612) and temperature sensing. Again, I would wait until the alternator reached the end of its useful life (if it's the original alternator, I wouldn't feel too bad about doing it with the battery upgrade).

3) Add a group 24 starting battery (same kind as house bank, i.e. AGM, Gell, or Wet).

The reason for doing #3 last is so that you have adequate alternator output to charge the larger battery bank.