Timer on a "dumb" battery charger

My boat has 32 volt and 12 volt DC systems, my 32 volt charger died. Yes some day I will convert to 24 volts but for now I'm staying with 32, that limits my options for new chargers. Both Newmar and Charles make 32 volts chargers, the Newmar is electronically controlled(like all the modern 12 and 24 volt chargers) whereas the Charles unit is a Ferroresonant transformer type, i.e. dumb charger, only works on lead acid batteries and does not have staged charging, it just keeps pumping out amps until it reaches the desired voltage, once there it tapers off the amps. I'm going to go with the Charles 9000 Series Marine Ferroresonant Battery Charger, driving factor is cost, the Newmar is $1500 and the Charles is "only" $1000.

I live two hours away from my boat, I visit the boat two or three weekends a month, ever since I have had the boat (about a year in the water with the batteries on the charger) I just left the charger on while I was away from the boat. And when I was on the boat at the dock I left the charger on, assuming it was like a "power supply. Now that the old charger died and I have been looking for a replacement I have learned a lot about chargers, I assume my old charger was also a Ferroresonant type charger.

I was not sure how the Ferroresonant chargers worked so I called Charles tech support, he said it would still float charger once the batteries were full and it would act like a "power supply" when the batteries were full. But then he made a comment that caught my attention, he said because these type charges just hold a constant voltage they can cook of more water and you have the keep an eye on the water levels, then he said some of his customers will put timers on the charger, and set the time to only run the charger a few hours a day.

So my question is, how many of you leave your charges on all the time and do any of you have timers?

Spend the extra $500. If you don't, you'll be spending it on batteries. Wait to you experience the weight of a ferroresonant charger. Installing it will be like lifting weights.

I have an ancient Newmar Ferroresonant charger, I use it when cruising to recharge batts, but not at the dock because I have enough solar to maintain batts managed by multistage controllers(though set to equalize monthly they tend to hammer the batts too much), so I`ve not bothered to update.
If I did want to use it docked, I`d update it to a multistage charger for efficiency, speed and batt safety and preservation. There have been a lot of advances since the ferro type was the standard.
Observing my ferro charger, I notice it eventually tapers the charge, however high it is set, to a very small almost nothing charge, split between 2 large batts.
Just my experience as a ferro user. The $500 you save on the charger you could spend on batts in short order if they get unnecessarily charged and underwatered. The timer sounds a good precaution, a couple of hours a day might be all you need, trial and (not too much) error may help find an adequate setting. I would not leave a ferro on 24/7 for weeks on end.

It is my understanding that ferroresonant chargers can be multistage, and for $1,000 I wouldn't expect anything less.

But in any case, leave the charger on for a few days and then measure the voltage with a calibrated voltmeter. Calibrate it against your car battery after resting overnight. Should be 12.6 volts. If it is less than 14.0 volts, then you may be ok leaving it on continuously. Then keep an eye on water usage.

While cruising and not hooked to dock or genset power I noticed that the dumb regulator on a new boat was set at 14.4 volts and was "boiling" water out of the batteries at a rate that caused me to add water after 4-5 days. I reduced its voltage to 14.0 and the water consumption dropped significantly.

With a dumb charger, the voltage set point is a compromise between charging rate (higher voltage pumps more amps in) and water consumtion (higher boils more water).

David

Sounds like the perfect spot for a solar panel.

Many of the new ones can handle the 40V required to charge your system.

Best of all YOU get to set the voltages for bulk and float.

Yes the old ferro resonant units would happily either undercharge or boil out all the water, UGH!

Just sitting a LA batt will loose 1/2% to 1% per day.

An old dear shot wull use 3% or so per day.

A overnight charge once a week should work fine ,,,IF the bilge pumps are not run by the batt set.

Timer on a "dumb" battery charger

How can I tell if my charger is ferroresonant or electronic?

My Charles 5000 charger is the original one that came with the boat when it was built in 2008. I leave it on 24-7 and I have new AGM batteries that I sure don't want to fry.

I don't run any DC loads when not on the boat, so maybe I don't need to leave the charger on 24-7?

Also, is there a cheap and easy solar "kit" I could plug in when away from the boat to trickle charge (but not overcharge) the house bank? I see those little panels that plug into the cig lighter, but I'm guessing they are not designed to charge a 12v 600ah AGM house bank.

Cardude, look it up on Charles' site. The 5000 as i recall are newer technology.
As for the OP, see if you can find a Sentry charger; it is kind of a cross between ferro and new technology as it turns off completely at full charge. I had one on my Hatteras, also 32v and it did a great job charging my two banks. It is also field serviceable and component spare parts are available. Most CruiseAir certified repair techs can work on them.

I too would otherwise urge spending another 500 on the Newmar.Another "smart" 32v charger is made by Analytics, several Hatteras I know have had good success with those and I believe they are somewhat cheaper than the Newmar.

Battery Chargers from Analytic Systems: Marine chargers, deep cycle chargers, and DC to DC chargers | Analytic Systems

How can I tell if my charger is ferroresonant or electronic?

It it weighs a lot, it is ferro resonant meaning has a traditional transformer inside. They can weigh over 50 - 100 lbs depending on the output requirements.

Electronic ones (switching power supplies use a switch turned on and off rapidly to charge a capacitor to make the voltage they want. They have a servo loop on the output side to adjust the cycle speed / duration to set the output voltage. They are usually light weight devices (under 20 lbs)

cardude01 said:

Also, is there a cheap and easy solar "kit" I could plug in when away from the boat to trickle charge (but not overcharge) the house bank? I see those little panels that plug into the cig lighter, but I'm guessing they are not designed to charge a 12v 600ah AGM house bank.

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The packaged solar trickle chargers are expensive and only supply a hundred milliamps or so which may not be enough to keep up with parasitic loads like CO monitors as well as daily resting losses for a big battery bank such as yours.

But you can put together a 2.5 amp solar panel system for about $150. Use a 50 watt panel, see http://www.amazon.com/Renogy-Watts-...455112653&sr=8-2&keywords=50+watt+solar+panel and
a 6 amp Morningstar controller which has an AGM battery jumper setting: Amazon.com : SunSaver 6 Charge Controller 12V 6A : Solar Panels : Patio, Lawn & Garden

I made up one to recharge my batteries on the mooring when I got back from cruising, and keep the batteries topped up on the mooring or on the hard during the winter.

I picked up some rubber feet at the hardware store which I screwed to the back of the aluminum frame and set it on a shady spot on top. Then I cut off the MC4 cable and spliced some 14 gauge marine cable and ran it down into the engine room. I hooked it up to the Morningstar input and ran the output to the batteries through a 10 amp fuse at the battery.

For a simpler installation plug the Morningstar output into a cigarette lighter outlet. Keep the breaker on that feeds that outlet and the solar panel will back feed through the breaker to charge the battery.

David

djmarchand said:

The packaged solar trickle chargers are expensive and only supply a hundred milliamps or so which may not be enough to keep up with parasitic loads like CO monitors as well as daily resting losses for a big battery bank such as yours.

But you can put together a 2.5 amp solar panel system for about $150. Use a 50 watt panel, see http://www.amazon.com/Renogy-Watts-...455112653&sr=8-2&keywords=50+watt+solar+panel and
a 6 amp Morningstar controller which has an AGM battery jumper setting: Amazon.com : SunSaver 6 Charge Controller 12V 6A : Solar Panels : Patio, Lawn & Garden

I made up one to recharge my batteries on the mooring when I got back from cruising, and keep the batteries topped up on the mooring or on the hard during the winter.

I picked up some rubber feet at the hardware store which I screwed to the back of the aluminum frame and set it on a shady spot on top. Then I cut off the MC4 cable and spliced some 14 gauge marine cable and ran it down into the engine room. I hooked it up to the Morningstar input and ran the output to the batteries through a 10 amp fuse at the battery.

For a simpler installation plug the Morningstar output into a cigarette lighter outlet. Keep the breaker on that feeds that outlet and the solar panel will back feed through the breaker to charge the battery.

David

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Awesome David. Thanks so much.

I like the cig lighter idea.

caltexflanc said:

Cardude, look it up on Charles' site. The 5000 as i recall are newer technology.
As for the OP, see if you can find a Sentry charger; it is kind of a cross between ferro and new technology as it turns off completely at full charge. I had one on my Hatteras, also 32v and it did a great job charging my two banks. It is also field serviceable and component spare parts are available. Most CruiseAir certified repair techs can work on them.

I too would otherwise urge spending another 500 on the Newmar.Another "smart" 32v charger is made by Analytics, several Hatteras I know have had good success with those and I believe they are somewhat cheaper than the Newmar.

Battery Chargers from Analytic Systems: Marine chargers, deep cycle chargers, and DC to DC chargers | Analytic Systems

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I finally found it. Looks like the Charles 5000 is electronic so hopefully it's OK to leave it on all the time?

I like the idea of turning off the charger and using the solar trickle charger David came up with, although I'm in a covered slip so not sure the "side angle" sun will be enough to keep the banks topped off.

Cardude:


You will get very little solar panel output in a covered slip.


See if you can put the solar panel on top of the covered slip and run a long wire down from it that you can grab when you return to the slip and plug it into a cigarette lighter outlet.


David

I replaced the old 60 amp charger on Northern Lights right after I bought it with ProMariner 60 amp smart charger. The original was a ProMariner and the PO told me he had to fill the batteries once a month. Spend the extra for the Newmar they are a excellent charger and will save you money in the long run. Powererboat reports did a test on chargers a few years ago and Newmar was the top pick.


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River Cruiser said:

... Powererboat reports did a test on chargers a few years ago and Newmar was the top pick.

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Reassuring, except my old Newmar is ferro-resonant.
Solar panels like direct overhead sunlight. Solar panel "farms" here,with acres of panels, adjust to the sun position.
Solar panels in a hinged 2 panel briefcase design which can be opened up and used when needed and packed away when not are available here. Typical panel size can be 2 by 50 watts.

"but I'm guessing they (small plug in pannels) are not designed to charge a 12v 600ah AGM house bank."


Recharge from dead , or heavy use NO.

But to make up 1% or so the battery eats just sitting every day , no problem.

BruceK said:

Reassuring, except my old Newmar is ferro-resonant.
Solar panels like direct overhead sunlight. Solar panel "farms" here,with acres of panels, adjust to the sun position.
Solar panels in a hinged 2 panel briefcase design which can be opened up and used when needed and packed away when not are available here. Typical panel size can be 2 by 50 watts.

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The one they tested was a 3 stage smart charger. Powerboat Report was a very useful publication, they had no advertising so no one to please with their testing. I trusted their results, in the end I think the cost of testing hundreds of products exceeded the revenue from subscriptions.


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Thanks for the input.

Dumb me I ordered the Charles unit right after I posted.... I did not see the Analytics charger now that I look at it I'm having second thoughts. I'm going to check to see if they have a restocking fee, if not I would only be out postage... hmmm not sure what I'm going to do.

But the more I look at the timer idea I'm thinking about putting one on my 12 volt system. It's a smart Newmar charger, and I leave it on all 100% of the time I'm at the dock, when I'm away from my boat the only 12v thing I leave powered on is the buzzer for the bilge pumps, the bilge pumps are 32v but the audible alarm is 12volts.

I leave my charge on all the time, it's on now and I've been home since the 1st week in January, the only time its off is when we are running and the gen is on. The 2 8D batteries use very little water, less than a quart per year, I check them twice a year now. The old charger required adding water every month. There is no way I would go back to a old style charger no matter how cheap they are.


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But the more I look at the timer idea I'm thinking about putting one on my 12 volt system. It's a smart Newmar charger, and I leave it on all 100% of the time I'm at the dock

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That's bad (adding another gratuitous thing in the system) and unnecessary thinking. Stop it! And just to reinforce a point, modern Newmar's are smart chargers at top flight kit at that.

Newmar | PT Series Battery Chargers | 24 and 32 VDC | 8 - 95 Amps