Charging issues

[Donald Tyson]

Alain, both house batteries are 12.08V. The starboard starting battery is 6.1 and is hooked parallel to the port side which is 12.8....13.3-13.4 with the solar on and the Stbd battery turned off.

[Donald Tyson]

I'm a bigger sort of guy and I can't see any switches on the charger or the inverter. I've used my camera to peer in to the back sides. Nothing. In the Starboard battery box there are fuses to starting battery charger and also a breaker to the house batteries. There is also a switch to turn on the DC Inverter. The little screen on the Inverter reads 11.9. not enough.

Tomorrow I replace the starting batteries and will re evaluate.
I'll also be getting a new 50 amp adapter to connect my house power to the boat.

I'm about at the end of what I can tolerate. Time for a technician.

[alainP]

Don, if your inverter is connected to the house batteries (as it should be) and those batteries read 12.08 V the 11.9 V at the inverter makes sense, the slight voltage difference is the loss in the wiring connecting batteries and inverter.
I agree that hiring someone to sort things out is the right move. Make sure to get a diagram when everything is said and done,

[Tom Hruby]

First of all: if your battery is fully charged and only reading 12.08 V you need to replace the batteries. A fully charged Lead Acid battery (AGM or Flooded) should be reading 12.6-12.8 V when fully charged, and with no load on it.
Also, if the voltage at your inverter (battery end) is reading less than the battery when it is not in use, the voltage drop is not a result of the wires, but rather a poor connection (most likely corrosion).

[Donald Tyson]

While I agree 12.1 or 12.08 is not a proper level. So I assume that those batteries are shot just like the surveyor said that they soon would be (2017)
Yes, this time I'll hire someone, I believe I know the right fellow and that he will let me watch or even help to learn. Thanks Alain.

[Donald Tyson]

Thanks Tom, I agree, Yes, I want to replace them all. They're all from 2017. Then if he wants to diagnose further he will know that it's not the batteries. Now that I have seen this I bet it was the batteries all along because everything was fine at Hontoon. 6-7 months can make a diff. As John Highsmith mentioned the fridge...Just to be sure... I'll have the tech run me through the sequence for using the fridge without draining the starting batteries. Replacing the Batteries should also assure that the connections are all good as well.

[thataway]

[Tom Hruby]

Also, always use "marine" rated wires. That is tin coated copper. Never use aluminum, copper coated aluminum, or just plain copper. After 29 years of going electric I know from experience that any of the latter will eventually corrode (even plain copper). In my first electric boat I tried to save money by using 6 gauge pure copper jumper cables and later 2 gauge welding wire, but all of these ended corroding inside the plastic jackets. The wires were corroded over the entire 15 ft of their length.

So, in addition to checking all the connections as suggested by Bob, you will need to make sure the proper wire was used.

[Donald Tyson]

Yes, One by one we will check. Thanks for mentioning the need for caution.

So, in addition to checking all the connections as suggested by Bob, you will need to make sure the proper wire was used.[/quote]

[Donald Tyson]

Sometimes I trap myself by making assumptions and not following them up with questions , huh, imagine that, me not asking questions!. When I bought this boat, I merely assumed that the solar panel worked to keep all batteries topped off. As it turns out, I now have learned that it is only hooked up to the port starting battery.
I drop this boat off at a local dealer today and he's going to look for a way to have the solar panel top off all batteries and keep everything fresh. Maybe way too expensive I don't know. He first has to find out what the potential is for the solar panel. It may only be good for one or two banks.
He will start by replacing all the batteries and then tracing and checking all the wiring. One of the things that he commented on was that all of my accessories are hooked to the starting batteries and not the house batteries. He may make some changes on that...

[Tom Hruby]

Check the wattage of the solar panel. If you can't get at the label assume the maximum is about 20 watts/square foot. If the panel is flat, and not facing the sun at 90 degrees and your boat is moving in different compass directions, the actual value is much lower. Here in the Pacific Northwest I have found that on bright sunny days my average between 10 and 4 is 65% of the rated capacity. So a 100 watt panel will produce only 65 watts x 6 hrs = 0.39 kWh/day.

On my 22 ft cruiser I was only able to put on only 12 square feet of panels (together they are rated at 260 watts), and I had to search far and wide to find some that filled almost the entire cabin top. At most I get only about 1kWhr of energy per day. This will not even recharge my house battery to account for the drain of the fridge.

So if you want to be able to shunt power from the panels to either the house battery or starting battery I suggest a simple switch. It does not make sense to try and charge both batteries at the same time from solar.

[Donald Tyson]

Tom you speak clearly on these matters, thank you. I'll check these panels out when I get the boat back or when I hear from the technicians that are looking that stuff up tomorrow. I have only one panel and it seems to be about 10 square ft. Without going online I have now idea what one kWhr is worth in terms of storage. But it seems that it isn't much. My area of PA is better than much of WA for solar efficiency. But still it is not Tulsa. I wonder if a suitcase gen wouldn't work more efficiently to charge batteries? That way I'd have the use of my roof back for dinghy storage..

[ssobol]

If the solar panel is more than a couple of years old, you might want to look into installing a newer one. Prices are down, technology has improved, and can solar panels degrade over time.

[Tom Hruby]

Don, 1 kWh of storage can be a lot or little depending on your power use. As a starting point a 12 V 100AH battery stores a maximum of 1.2 kWh of energy (12 V x 100 A = 1.2 kWh). However, a 12V High end lead acid battery only stores about 0.7 kWh of energy because they should not be drained below about 60% of capacity without seriously affecting their longevity. This is for the more expensive lead acid batteries. The less expensive ones have a limit of 50% of capacity. Lithium Iron Phosphate batteries on the other hand can be taken down to 10% of their capacity without affecting their longevity.

I have been giving presentations on electric propulsion at the Port Townsend Wooden Boat Festival for several years and have collected some fun information.
1 kWh of energy stored is equal to the energy stored in:
3/4 of a loaf of bread
2.7 oz of gasoline

What can you do with 1kWh of energy:
Toast 89 slice of toast
Run a modern kitchen fridge for 20 hours
brew 12 pots of coffee

AND on a boat:
Run a small portable fridge that draws 5 A for about 2 days
Run your cabin lights and running lights also for about 2 days if you have LEDs.
run my C-Dory for 2.5 miles at 5 mph

So if you have a solar panel, it can be used to supplement your house battery, and if the sun cooperates even keep it topped off. Since your starting battery is usually connected to the alternator on your motor, the motor should be adequate to keep it charged up.

Regarding a back up generator:
It all depends on how much time you spend motoring relative to anchoring and whether your outboard has a stator or alternator. In either case the output is about 25-40 amps depending on the motor size. So at 12V and 30 Amps it puts out 360 watts/hour (0.36 kWh). To get 1 kWh into the battery will require you to run the outboard for almost 3 hours.

[thataway]

My experience is that running a full day; usually 6 to 8 hours, with the Honda 150 on paper putting out 44 amps max., and limiting the FeLiPO4 charge rate to 30 amps per hours, (the engine, and other house loads are available to be charged with the 14 amps "left over" is ample to keep the two 100 amp hour Li batteries, running the freezer/refrigerator, and inverter to use indction stove and microwave.