Batteries to run electronics/autopilot/HP Downriggers and…

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kaelc

New member
I’ve been reading some great threads on batteries and hate to cover stuff that is already covered but here goes. I have a starter and house battery both 27 series and guest 20amp charger. With dual 7 inch Lowrance electronics/autopilot/HP Downriggers when I troll for 3-4 hours with the 9.9 Honda kicker 12amp alternator then run with the 150hp for 30 minutes the batteries draw down below 12v when pulling out commercial crab traps.

I haven’t been confident with my batteries and now I’m really not. Overnight on the hook with the wallas scares me before I add a fridge. To keep things light and simple I’m thinking buy a starter and house 31 series batteries and add 100amp lithium ion cabin battery with solar and charging protection, and run the electronics/fridge of that? I also have radar etc, but don’t use it all the time. How is the windlass usually wired from the factory is it directly back to the house battery for an 2007?

Thanks for your input.
 
Lead acid batteries will lose voltage when pulling a crab pot or shrimp pots. It's asking a lot to not expect that. However, they should quickly recover to their base voltage, or at least near it if they were fully charged and you haven't run them down. Your windlass is probably wired to your starting battery, with the idea your engine will be running when pulling your anchor, but you're going to have to chase wires to be completely certain. 12V fridges are power hungry beasts......good luck! A lot of folks add a honda generator because of the current draw. Group 24 and 27 batteries I've found to be marginal as an RV battery or boat battery. They just don't have much capacity, but are ok if you live in a warm climate and are just running lights and the usual stuff. Throw furnaces in, a fridge, and all your stuff? You're right to be thinking of other options.
 
I cannot answer the question about the pot hauler (?)--but the windlass should be wired to the starting battery--and the engine running. The same should be followed with the pot hauler. It is not unusual to have the battery voltage fall below 12 volts when there is a heavy load. The voltage should be measured with a meter wired directly to the battery which is involved. I like to use the Victron 702/712, but there is a Chinese variant which is a fraction of the cost, and I am using it for a "Li battery pack" I carry in my truck or suv for chest freezer).

Aili battery monitor gives voltage, state of charge, amps in and out etc. This requires a shunt. I don't know how well this will hold up with time, and there is no bluetooth.

For the most part I use group 31 AGM as the batteries for the 25's I have owned. I have over 3 years experience with a 100 and then 200 amp hours Battle Born LiFePO4 battery banik. It is not really "Plug and Play". You have to have a DC to DC battery charger, adequate Fuses and switches. I had a Sterling 12-12 DC 30 amp running off the group 24 start battery. I also had a VSR between the engine start and two house batteries. The output from the DC to DC charger goes thru a 30 amp circuit breaker via #10 wire to the Li battery bank which is forward under the bunk. From the Li battery, I have a 300 amp fuse, and 500 amp on/ off switch. There is also a 80 amp breaker between the Victron Multplus 2000 watt PSW inverter/80 amp charger. I monitor this system with a Victron 702 (would use the 712 now). There is a second output to the circuit which feeds a chest refrigerator and a chest freezer. This is fused at 20 amps. This feeds to a double pole double throw switch, so I can run the Freezer and Refrigerator on the house battery if necessary. I have temperature monitoring on the Sterling DC to DC charger, the LI battery bank and the Inverter charger. I have the remote for the Victron Multiplus.

The Li battery system is not cheap: I have in excess of $3,500 in mine on the C Dory 25. The second portable pack with 100 amps, I use a 10 amp dedicated Li battery charger, a Victron Orion 30 amp smart DC to DC charger from one of the batteries in my truck or SUV; #10 wire, with appropriate circuit breakers. I used the Aili monitor with shunt. The battery I used there was Renogy ($800). However now I would use the Chins/Ampere Time, based on the Will Prowse Review on his U tube channel.Chins/Ampere Time review. I used a standard battery box, and could put all of the items on inside it except the DC to DC charger (needs ventilation, so bolted to the outside), and the 10 amp AC Li charger.

The total cost for the "portable" Li Fe PO4 system was close to $1500. By using the cheaper battery, you can get it down to about $1200. As long as you are not running a 2,000 watt inverter, you can get by with the single 100 amp hour battery. (depends on how much you run the inverter and what you run it for).

I would have a cheap mains power AC 10 amp charger. Mine was made in Taiwan and has a LED read out of voltage, amps in, State of Charge etc. It cost in the $60 range.

For solar recharge in the PNW, you will probably need 200 watt output to fully charge the 100 amp hour battery.

Edit: we find that a single refrigerator / freezer and the built in ones, run about 60 amp hours in a 24 hour period. It may be less in the cool PNW.

The power assessment is a good idea, but be a little careful, since the one linked to is for a sailboat, both underway and at anchor. There may be parasitic and minimal draws which you are not aware of. That is why I prefer to use a good meter, with a shunt. Do not rely on the engine LCD read out, or a dash gauge.
 
thataway":267mfxl9 said:
The power assessment is a good idea, but be a little careful, since the one linked to is for a sailboat, both underway and at anchor.
Click to expand...
Thank you for catching this Bob! I did a quick Google search and gave the OP the incorrect link without checking it. My apologies to the OP! This is what I intended to post and it's the worksheet I'm using, with modifications which are easy to do.
https://newcontent.westmarine.com/docum ... late1.xlsx

Bob's comments about parasitic draws still apply, of course!
 
Nothing wrong with knowing how much current is flowing and I like the gauge Bob tossed out there and I'm surprised it's so inexpensive. I have an Extech 380942 for that though, but it's not something that people that don't work on stuff often would want or need. I personally think neither are required though to nail down how many amps you need as you are likely going to build in a decent reserve capacity either way. Ballpark math is probably enough.

I like the LifePO4 technology a lot and have found that one can crawl very deep into the LifePO4 rabbit hole and buy lots of stuff. Before you buy one, do educate yourself and don't buy one without a good BMS as that is probably the best safety measure there is. I'd also talk to one of the tech/reps and explain your intended usage and how they would set things up. I did with relion and was thankful for their professional insights.
 
T.R. Bauer makes a number of excellent points. (I was not aware of the Extech being a high quality item. ). I had considered the Fluke as sort of the gold standard. (There are now cheaper Fluke meters). I don't have that quality instruments. I get by with a Radio Shack or Craftsman clamp on amp meter (both AC and DC). Most of my measurements in diagnostic is with relatively inexpensive digital volt meters. However the direct measurement of power use (amps) is limited to 10 amps. (Be sure and read instructions before using any meter). For those who are just getting into the electrical circuits on the C Dory, an inexpensive digital volt meter works fine for diagnostic work. The clamp on meters will measure up to 800 amps AC and 400 amps DC (way beyond what most of us will ever see). You can buy these meters at Home Depot, Lowes and Amazon.

I would buy a book on 12. volt wiring on boats such as "12 Volt Bible for Boats" (a bit outdated), Nigel Calder's "Boatowners Mechanical and Electrical Manual" is a little more up to date. There is a very good website on electrical with a number of articles. I recommend that all read these. I don't agree with all of his conclusions, but he always makes excellent points.https://marinehowto.com/category/electricalHow To Marine web site on electrical/ Unfortunately the author had a stroke, and has stopped writing articles. The store is closed.

To be clear, the Victron and Aili Meters are permanently installed. I have one meter on my LI battery bank, and a separate meter on the flooded lead acid house bank. If you go beyond the simple electronics, windshield wipers, stove, bilge pump etc, and stay out overnight then I feel that all boats should have a monitoring system.

Also there is a lot of power, and although the batteries are "safe". If you make a mistake in hook up, the results can be far more than even with a lead acid battery.
I had been following the Li battery Trent since about 2005, when one of the full time RVers put in about 1200 amp hours of LiFePO4 batteries. The company rebalanced the battery pack yearly, by tearing it down and checking each cell.

Many folks take shortcuts--ie the alternator can put out enough for the Li battery, and I don't need a DC to DC charger. I don't need temperature monitoring. I don't need a good BMS system. I can hook up the Li battery to the leas acid battery directly, I can use a cheap battery switch to handle that 300 amps when I turn the inverter on and run the microwave and induction burner...I can use the batteries for engine starting (some you can) Each of these could be a major mistake.

Review Will Prowse's videos. He is more interested in RV's. A lot of very good information in his series. The Hull Truth now is having good discussions. Many of these are in tolling motor applications, but again principles all are the same.
 
Just looking at the numbers on that Excel Spread sheet makes me think they are guestimates and not very realistic. Too many Zero requirements for things like phone charges, water system, anchor lite vs cabin light or instruments. Either a day sailor or . . . . ???

The chart from "Sailboat Cruising" seems to be much more realistic in terms of usage times.

Harvey
SleepyC :moon

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One really has to make the measurements if they want accurate numbers. For example, many boats now have LED lights which may draw from 50 to 150 milliamps. The 25 watt incandescent bulb can draw 2 amps (25 watts).

There are bilge pumps which do sampling: For example the Rule Auto sensing pump will turn on every 2-1/2 minutes for about one second to sense for water. If water is present, the pump will sense resistance and continue to run until all water is removed. After that, it will resume checking for water every 2-1/2 minutes. This is claimed to use 500 milliamps in 24 hours. The pump draws 1.,9 amps when running. The reality is that the pump does draw more than 500 milliamps in a 24 hour cycle. In this case, one of the permanently monitors will give you the answer if this is the only current draw, and no water in the boat.

I have also made "temporary" cumulative meters, with a cheap Bylite volt/power/energy meter (less than $20 with shunt), by wiring the shunt in temporary fashion on the negative wire. It will read amps consumed over time. You can either put it on a timer, or Tim it your self. It is manually reset and not waterproof, so I would not use it for the primary monitor equipment.
 
Not sure if this information is pertinent as I just kind of scanned this thread. But this is my setup on my 25. I have all LED lights, except for the red and green nav lights which are incandescent, but only running when the motor is running. I have the original equipment refrigerator and an Engel Freezer. (I run both on number 3 if that means anything. Frig stays around 40 and Freezer around 25.) I use a c-pap without humidification. I have a Webasto heater, and some carframo fans. I have one group 27 battery for my starting battery and two group 29 batteries wired in parallel. A typical cold night on the hook involves running an LED anchor light for maybe 12 hours, a fan and c-pap for 8 hours, a few cabin led lights for a couple of hours, and the heater (8+ hours). My vectron battery monitor will show 75% or better remaining in the morning, when shutting down with 100% 12-15 hours earlier. With less load on the batteries in the evening, I will show a higher percentage remaining. My windlass is wired into my starting battery, and ran with the engine going and sometimes idled up. Colby
 
hardee":2fkdp6mi said:
Just looking at the numbers on that Excel Spread sheet makes me think they are guestimates and not very realistic....

The chart from "Sailboat Cruising" seems to be much more realistic in terms of usage times.

Harvey
Click to expand...
That may be, but I don't think the author intended the data in the spreadsheet to be accurate or complete. It's offered as a worksheet for anyone to utilize, and the author took the time to fill in a few fields as an example. The intent is that the user will substitute their own data and finish filling in empty fields and add new fields when required. In terms of usefulness and functionality, it's a much better spreadsheet than the "Sailboat Cruising" one I posted by mistake.

I'm using it to play around with different scenarios - underway 1 hr/day vs. 8 hr/day, plenty of sun vs. a week of rain, etc. It's extremely helpful, but it's only as accurate as the data you provide.
 
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