Battery charger comparison

In a recent thread about freezers and the 50qt ARB unit, Sunbeam said it was drawing 25-35 amp hours per day. In the same thread Bob posted the following,

"We find that 30 amp hours is a good average for our dometics over a 24 hour period. We use one as a freezer and the other as a refrigerator. We use about 30 amps each 12 hours"

In my own testing, I am finding we can create and maintain ice with our Engle freezer using 30amp hours per day.

Boris is using more power due to the draw of the built-in refer on the 25 but based on experience of others and my own, I think saying anything under 60 amp hours is suspicious is missing the facts.

Based on some real use by some of us Brats, it looks like that number would be closer to 30.

Bob, did your units really double their draw from 30-60ah each from one trip to another? That seems like a pretty big jump.

Greg
 
Bob, did your units really double their draw from 30-60ah each from one trip to another? That seems like a pretty big jump.
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A lot depends on the ambient temp and depth of the freezer temperature. I had the freezer at 4 degrees on this last trip. I was running both off the same group 31 AGM battery (110 amp hours) with recharge 2 x a day. Powell runs in the 90's to 100's in the day. Also I did not use my extra insulation on the freezer (external 1/2' foil covered foam) This is why there are many variables. Granted that the built in refers are not as well insulated as the chest types. The Domestic tend to use a bit more than the ARB's

I was also more accurately measuring the amp draw, as well as the voltage on this last trip with the meter dedicated to these units. The AGM battery has a better acceptance rate than a flooded lead acid battery. I find that with my charger I run at 30 to 31 amps for an hour, in the bulk phase, then the charger begins to taper down. I usually shut down the generator when the amp meter is reading 3 to 6 amps. This is still not thru the entire absorption phase. My fear is with many 20 amp chargers, especially if they are not able to put the entire 20 amps into the refer battery, that the battery may be chronically under charged.

With the larger engine alternator, it may definitely require less generator time.

With my Honda EU 1000, when I first start up, and the charger is running at 31 amps, I cannot run anything else on the generator. Later I can add the Torqeedo and then the house 20 amp Mastervolt.

West marine 30 amp portable charger I have an older version of this same charger. I have not tried this one personally, but know two other C Dory owners who have, and I have watched it in action--seems to be similar. Watch battery temperature.
 
Brent, my 25 came with what I believe is the same model you bought. I didn't know much about them, so did a little reading, and decided to keep it--if it failed, I would go to the Mastervolt, or Victron. I monitor it with a battery monitor (voltage, amps in and amps out, state of charge).

The battery charger does what it says. It charges the battery--at up to 10 amps per battery. It then floats, and droops off for a few hours. If any load, comes back on. If the battery voltage is 12;7, it comes on for a few minutes at 13.3 and then drops back off.

I am very happy with it. I happen to be using the flooded lead acid batteries which came with the boat. I did run the refer and freezer chests on the system, before getting the LiFePO4 batteries, inverter/Charger and engine B to B charger. It handled the lead of the refer/freezer well enough.
 
colbysmith":1t3oded5 said:
I just recently installed the Victron 712 battery monitor, and like it. Colby
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I have the Victrom 602 and it is ok. It calculates the battery state of charge based on what it thinks the current rate has been. I find that my meter will often show a low + or - current flow with the batteries off (only the bilge pump is directly connected to the battery and I know when that is on).

For example, I may find it with a small negative current with the battery off and no charger on. So I'll zero it out. Then I'll come back later and it'll show a small positive current, again with the battery off and no charger on. So, I'll zero it again. Then later I'll again find it with a small negative current flow.

So I take what it says with a grain of salt, especially if the things have been left alone for awhile (low indicated currents x long time = dubious battery readings). If I am actively using the boat, then errors in the current flow and SOC don't have time to build up to large erroneous readings. If the boat is in storage for awhile (e.g. weeks between uses) I don't believe the SOC reading until after I charge the batteries again.

Having a battery monitor is like having a fuel flow meter. After you use it a few times, you don't need it anymore.
 
I adapted a Vectron 40 amp automotive battery charger to my CD-22 when I modified the electrical system to use four Group 27 deep cycle marine flooded lead-acid batteries to be able to use a anti-ventilation plate mounted trolling motor for slow trout trolling.

One of the several features it had that you usually don't find on marine battery chargers was an anti-sulfation cycle. The charger applies high frequency alternating current to the battery to dissolve sulfur compounds that accumulate on the plates as batteries age, especially when left not fully charged.* I didn't conduct any scientific tests, but it sure seemed to extend the life of the batteries when used once a month or so in addition to the regular charging cycles.

The charger also would test the motor's alternator output and do a couple of other tests on batteries.

Just another thing to think about! :wink

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*Sulfation: What is it and How to Avoid it? - crownbattery.com

www.crownbattery.com/news/sulfation-and ... aintenance] https://www.crownbattery.com/news/sulfa ... aintenance

"While there are anti-sulfation devices available that will apply pulses to battery terminals to prevent and reverse sulfation on a healthy battery, they will not reverse the damage completely and are not always recommended. Sulfation is the number one reason you should not store your battery with an empty charge."

******************************************************************

Joe. :teeth :thup
 
The anti-sulfation cycle is why I use the BatteryMinder brand chargers when my boat is in the barn. I rarely use a charger at the docks. Not sure how much I trust the old Guest 5/5/10 that came with the boat. The one good thing about it is that it is water p[roof and can live under the splash-well. Only 1 LED there and it shows green if it is charging.

I have been looking at a Blues Seas, but most of their chargers are BIG for a 22 that has such limited space, and they need to be mounted vertically. They have a new one that just came out smaller, and 20Amp output. Here is the link:

https://www.bluesea.com/products/7608/2 ... America%5D

And here is the link to the "Sales Page" from Blue Seas:

http://assets.bluesea.com/files/resourc ... 028820.pdf

It is about half the weight, (6.75#) and is IP67 water proof, so should be able to be mounted under the splash well, (at least I have not found any place that contradicts that).

Harvey
SleepyC :moon

Friends_Cal_09_10_Oct.thumb.jpg
 
The charger that Harvey mentions has a combiner built in--so that the batteries are charged from the start battery, without the need for VSR or Combiner.

Having a battery monitor is like having a fuel flow meter. After you use it a few times, you don't need it anymore.
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I don't agree 100% with this. The reason is if you have refrigeration, or other variable loads, such as a diesel powered heater, you do not know exactly how much power had been used. (I also have found fuel flow meters very helpful as to the amount used in the specific conditions, including weather, attitude of boat, and loading--especially when making long runs close to the fuel capacity--such as in AK. Many fuel flow systems are accurate enough that you can predict how much fuel you will need at the next fuel dock.

Also be cautious about " parasitic draw" from memories in electronics--such as the station memory in a stereo. Some are wired around the battery cut off switch.

I have been using the Victron and similar battery monitors for a long time--(used separate volt and amp meters before these came along). They not only manage the power, but also help to keep from over discharging the battery banks.

New on the horizon is the Balmar SG200. This combines the "Smart Gauge, which just used battery voltage, with a shunt--in fact it has previsions for using up to 32 shunts for multiple battery banks... The cost is less than the Smart Gauge. @ $220

Another option from Blue Seas is the multi function meter 1850 which will be available in July 2019:

DC System Monitoring (up to two batteries)
One input monitors the DC voltage, state-of-charge, current for one battery bank and another input monitors the voltage of an additional battery bank. Alarms include high and low voltage, high current, and low battery.
AC System Monitoring
The VSM monitors a single AC voltage, current, and frequency. Alarms include high and low voltage, high current, and high and low frequency.
Bilge & Tank Monitoring
The VSM has two inputs that can be configured as a bilge or tank monitor. When configured as a bilge input, monitoring functions include pump active, cycle count in the last 24-hours, average cycles in a typical 24-hour period, and total cycles. High alarms can be set for both the minutes of run time in the last hour as well as the number or cycle counts in the last 24-hours. When configured as a tank input, tank status can be represented in both capacity (gallons or liters) or as a percentage of capacity. Custom tank shapes can be auto-calibrated or programmed. Both high and low level alarms can be set for all tanks.


NMEA 2000 certified and uses standard connectors. This allows a single network backbone to be installed for multiple NMEA 2000 devices. The m2 VSM can sahre certain monitoring fuctions with other NMEA 2000 compliant screens, such as CZone Displays Touch 5 & Touch 10.
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The problem is that we don't know the price of this unit yet.
 
Bob said,
"Also be cautious about " parasitic draw" from memories in electronics--such as the station memory in a stereo. Some are wired around the battery cut off switch."
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One of the last wiring projects I had done was to put in an external power switch on the stereo for that exact reason -- mini LED light and always on power for memory and clock. Didn't need any of that.

The only things wired directly to my batteries are the Wallas and 1 Cig lighter plug to run my rear view camera on when towing.

Even the power switch to the Fell Marine MOB+ device has an external power switch.

No more parasitic draw.

Harvey
SleepyC:moon

Friends_Cal_09_10_Oct.thumb.jpg
 
My boat is wired so that there no loads except one of the bilge pumps and the battery monitor itself that is connected directly to the battery.

A lot of modern radios use flash memory for the presets and settings and don't require a continuous power source for the memory anymore. The radio on my boat doesn't need memory power. The radio in my car only needs power to keep the clock going. The station memory and settings do not.

IME, after using the FF meter and the battery monitor a few times, you know what the fuel burn is for various conditions and what the electrical loading is. For instance, I now know that the overnight battery depletion by my fridge is 12-15% and that it takes about 25 minutes to recharge that amount at ~1K idle RPM (boat is much quieter at this RPM than true idle because of resonance). I don't need to look at the battery monitor anymore to know what the state of the battery is in the morning when I get up or how to get the battery back up to charge.
 
I'm pretty much like SSOBOL. The only things hot wired to my batteries, are the Victron monitor (of which I'll pull the fuses out of the positive wires during winter storage), both bilge pumps and the battery charger. Everything else comes through the main battery switch. There is no parasitic draw from the bilge pumps. I also have a wiring harness connected straight to my starter battery that is for my small air compressor. But nothing on the end of that harness unless I plug my air compressor into it. Colby
 
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