New batteries and charger

jssailem · Nov 22, 2019

The easy way is to try starting with the charging system. But that is not the best. It is like buying the feed but not knowing how big the horse is needed to carry you and how far you are going to go.
Start with a daily power demand chart. How many amp hours are you going to use per day and how many days are you going to be away from a charge? Multiply the two together then double that number. That will give you the total number of battery amp hours you need. Now you can look for batteries to fill that need.
E.g. 45 amp hours per day. 3 days on the hook. Equals135 amp hours times 2 equals 270 amp hours. If a group 31 battery is good for 110 amp house then you nee 3 group 31 batteries to meet you assumed demand need.

Group 31 batteries are relatively large and powerful batteries, featuring 20h capacity in 75-125 Ah range

Then you can properly size your charger system, both alternator and dock systems.

dlochner · Nov 23, 2019

That charger is an antique. The Ray Jefferson brand is long gone and was never seen as a high quality brand, sort of an economy. They have now morphed into Ray Marine through various buy outs and near bankruptcies. Interesting information but adds little to your decision making except to convince you to place the charger on display alongside of those cameras. Becarefull when removing it, it will be heavy. Don't be surprised if it weighs in around 30lbs (14 kg).

The Sterling/Pronautic chargers are highly rated, have built in charging profiles for different battery chemistries and a custom profile. Binacle Marine in Halifax carries them. A 30 amp charger would be better for a 200-250 ah bank. Rule of thumb, 10% of the bank capacity plus some extra to run dc loads while charging. The cost difference between a 20 amp and 30 amp charger is not all that much.

The best bang for the buck are 6v GCs and they weigh less so it is easier to move them around. AGM and Gel batteries have some positive features, however, they are intolerant of being left in a partial state of discharge, so they have to be recharged quickly and with the appropriate charging profile. Lithium are really expensive. FLA batteries are more tolerant of abuse and being left in a PSOC.

If you go with GC batteries, Dyno makes a very nice battery box. The SBO store used to sell them, perhaps they can still have them drop shipped.
Fisheries Supply has them. Fisheries Supply - Marine Supplies Since 1928 Page

Benny17441 · Nov 23, 2019

Start with the basics, analyze your needs to determine the sizing of the battery bank (power survey). Your type of sailing will determine the desired reliability and performance by battery type; also availability will need consideration. Then size your inboard charger appropriately for the type and size of the battery bank. Redundancy is a factor to insure that at least emergency power is available to start the engine. The last factor is economics, once you have determined your operational and equipment requirements you can overspend but not underspend.

Scott T-Bird · Nov 23, 2019

I'd recommend the Sterling/ProCharge chargers for the reasons given above. The one thing I noted is that the 20amp and the 30amp models are basically the same size and weight so I bought the 30 amp simply because there was very little difference between the 2 other than the output. Sure, it cost a little more. I think stepping up to 40 amp was a different box altogether, so 30 amp seemed like a good place to settle for me. YMMV

Richard Bryer · Nov 23, 2019

I replaced that very same charger on my H34 about 12-14 years ago. I replaced with a used Xantrex 20 amp. I also have 3 batteries- one grp 31 and 2 grp 24.
I replaced the first 31 15 years ago and the last 24 9 years ago. Last year I replaced all three with exactly the same Costco flooded batteries. That means my oldest battery- the grp 31 was about 12 years old. The newest 8 years old. Cant believe they lasted so well.

dlochner · Nov 23, 2019

DArcy - Islay Mist said:
Is 175 A-Hr per day excessive for a few people on a 36 foot boat? Does anyone have real-world data they can share?

I'm also considering getting rid of the 1/2/Both switch, putting the batteries in one bank and using an ACR to charge a starting battery.

Working backwards, yes your plan to make both house batteries in one bank and use the ACR to charge the starting battery is a sound plan. Bigger banks are more efficient than smaller banks. Starting batteries recharge quickly as they use a lot of energy for a very short time which turns out to be not much energy. Just make sure the alternator, solar, and charger all go to the house bank and not the start bank.

Electrical loads can be managed. Refrigeration is the big draw followed by lighting. Changing out the incandescent bulbs for LEDs will significantly reduce your energy consumption. Turning off electronics when you are not using them will also help.

I can't give you hard numbers, however last summer I was monitoring my battery bank state of charge. We have 4 6v GCs in a bank for 460 ah when they were new 5 years ago. This year we added a Compass Marine 90 amp alternator with external regulation. We went almost a week without connecting to shore power and without dropping the SOC below 50%. We did motor some, perhaps 7 or 8 hours in that week. Monitoring the battery bank's SOC is critical. It would be easy to drop below 50% SOC and damage the batteries.

Our refrigeration runs about 60 ah a day, our most used lighting is LED as is our anchor light (we anchored out 5 or 6 nights), we turned off the electronics when they weren't being used, and did not use the autopilot very much.

Next spring we will be leaving on an extended trip out the St Lawrence and then south. Before leaving we will add 300 watts of Solar and expect the solar and occasional motoring will meet our electrical needs.

shemandr · Nov 23, 2019

I had a 36 foot boat and a 400 amp/hr battery supply. It was barely adequate for refrigeration, and the incidentals at anchor. We had no solar and only the 35 amp alternator which was OEM. It added very little to charge. Mostly we charged at the dock every second or third day when on a cruise. Today I would put on some solar chargers.
There was a poster a few years ago who had a spreadsheet for energy consumption. It was good for making an energy budget. By going through the items on it you would learn that there are only a few major consumers of energy - refrig being the one. Bill Roosa: calculating amp hours?. Follow his posts to get to the spreadsheet. I found it useful.

dlochner · Nov 23, 2019

A quick look at the energy budget and I think the numbers are some what inflated. For example the wash down pump and windlass will only be. used when he engine is running, their draw will be met by the alternator. Will you really transmit on the VHF for20 minutes a day at high power? Also the computer, microwave and inverter values seem high. Inverters can be turned off except when using them. There's a price to pay for having them always on and available.

Kings Gambit · Nov 24, 2019

My power issues for the house of several years experienced whenever away from the dock for long were effectively solved with the combination of 4 GCs wired in series-parallel to produce two 12-volts at about 470 rated amp-hr, two 85-amp solar panels, and a Balmar 150-amp alternator w/external regulator and temp sensor. After adding the Balmar, I ended up needing only one of the panels at a time.

Our power budget varies with season. In the colder months we run the Espar diesel-fired heater in the morning, evening, and sometimes through the whole night. Still, the fridge, which uses on average about 1-1.5 amp-hr/hr, or about 35-36 amp-hr/day, typically draws the most. However, a few hours with autopilot engaged adds up as well. With the Balmar + solar we’ve gotten the charging time down to an average of about 1 hr/24-hr day (two 30-min bouts) or less while laying at anchor. No inverter for me for things like microwaves, Espresso coffee-makers, hair driers, TVs, etc.

You have to figure in or allow for those insidious little power eaters. One, the solenoid valve that opens the gas line from your propane tank to the stove. Those little buggers draw about 1amp-hr/hr. Have to remember to switch it off after cooking or it will rival the fridge. Charging cell phones, iPads, and hand-held VHFs, esp. if you 4 or 5 cell phones aboard that need recharging every few hours also adds up. Whenever we take crew or passengers, we end up with about 1cell phone each. Recently, I put a DC plug in fwd cabin where the guests stay so not to have 2 to 4 cell phones plugged in at the nav station.

Benny17441 · Nov 24, 2019

175 Ah per day is a lot what are you running besides refrigeration? There are tricks about using refrigeration 1) before going on a trip precool the fridge for two days with shorepower, 2) A full refrigerator runs more efficiently 3) Do not open the fridge more than necessary, pack drinks in a cooler 4) frozen foods help maintain temperature 5) when underway we will start the engine every two hours and motor sail for 30 minutes to help recharge batteries. One word about the solar panels, they only work when the sun is out and during a few consecutive cloudy days you may find their output to be inadequate. Solar panels ratings are based on an average over a number of days, you cannot rely on being able to get the rated power every day. Figure out what use you will give the boat 80% of the time and try meet your power needs for that 80%. If you are just going to take 1 or 2 extended trips in a year do not waste your money equipping the boat to meet those extraordinary needs. just adapt and look for alternatives. Packing a portable generator, stopping at a transient slip in a marina, rationing usage, etc.

wbernard594 · Nov 25, 2019

My batteries and charging system are almost new on my 32 Vision and was investigating a small generator for extended cruises. Instead of a generator I purchased a DEWALT DXAEPS2 Professional Power Station Jump Starter: 2800 Peak/1400 Instant Amps, 1000W Inverter, 20 PSI Air Compressor, Battery Clamps. I can charge it while underway on the engine and it will power all of my 110 appliances including, power tools, fans, etc. at night without using a house battery inverter. It can be used to jump the battery and also has usb charging plugs, a good bright light and an air pump to keep the bumpers full. No exhaust, no noise and I can position it anywhere on the boat I need it.

Stan Galper · Nov 26, 2019

I won't repeat all of the benefits of AGM batteries, but with solar panels, AGM's are the way to go. They don't tolerate being undercharged but solar at the dock will fully charge and maintain them in between trips. My setup is four Group 27 AGM's for about 400 watts total and a 140 watt solar panel with an MPPT charge controller. I have refrigeration and live in Florida. I can generally spend 3 or 4 days at anchor without going below 50 percent but will start the motor if it goes any lower. I think that going for the highest battery capacity and discharging them to a lesser percentage is more cost effective than having less capacity and a deeper discharge percentage. I'm going on 8 years with my DC Fullriver AGM's.

captain jim 70 · Nov 26, 2019

Let me cut right to the batteries. I bought two Series 31 AGM from Defender with an 18 month 100% guarantee at more than $340 each. One battery was dead cold after 14 months. Defender refused any assistance and sent me to the distributor who sent me to the manufacturer who sent me to Defender. Needless to say it took more than two months to right this issue. I would recommend going to Batteries Plus for AGM items. They offer a one year guarantee and are locally available at less than $275, no shipping, and immediate pick up. Never using Defender again.

Mr Fox · Nov 26, 2019

I don’t personally have them (my power needs are simple) but three of my friends have firefly carbon foam house banks on their boats (all over 40 feet) who I would confidently label very serious cruisers (vinal haven or Boston to BVI every year, sometimes sailing for 2-3 months at a time).

They all have serious power needs; water makers, refrigeration, TVs and microwaves plus tons of electronics. I do not know what they run on shore power only (except for air conditioning). They are all very happy with them, the batteries have worked reliably as advertised and have thus far they have all said the fireflies have significantly outlived their previous battery choices (these were varied, but none were lithium). I know they would all buy them again.

Sorry it isn’t as helpful as first hand knowledge but hopefully it gains you some insight.

dlochner · Nov 26, 2019

The early Fireflys had some issues with quality control, however, I believe many of those issues have been resolved. Bruce Schwab at Ocean Planet Energy is an industry leader. Nigel Calder has recently joined as a minority partner.

Mechone · Nov 27, 2019

AGM lifeline are one of the best batteries mine are going on 10 years no problems with solar charging a sterling 30 amp charger. At the dock the sterling charger will supply the power not your batteries ,you can remove your batteries and it is a power supply. It's also world voltage so you can plug it into 220. Also charges flooded, gel ,agm or lifepo4 if you upgrade to lithium later. Also I bought the remote for the nav station

New batteries and charger

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