Shore power & temp control?

[4kMike]

Hi all!
We are now sailing in Caribbean. When running genset and charging batteries w. Shorepower charger, we don't get more than 14 A to the batteries.
I just found on manual that our Ctec 300 (max 25 amp) charger has battery temperatude control cutting current down when over 25 deg C!
Any suggestions, fellows..? Should I disable (cut off..?) the temperature sensor.. or put it to the ice box..??? :-)

[smac999]

Probably because you are consuming amps.

If the boat is using 11a. (Fridge, lights, etc). That only leaves 14a left to the battery.

Chargers reduce voltage when batteries are warm. Never seen one cut back amps.

25a is too small. How big is your battery bank?

Here 100-200 amp charger is common on a 30-40’ boat.

[kchace]

I'm not saying that your battery charger is working correctly, but it is a fact that putting too much charge into batteries that are too warm will damage the batteries.


Ken

[Montanan]

Do not artificially cool the charger's temperature sensor, it is there to regulate the current so as to not allow an overheating of the charger. Resistive losses increase by the square of the current.

If you require additional amperage then get a charger with greater amperage capacity, and / or place the entire charger in a cooler ambient environment, or place a cooling fan so as to blow air over and into the charger so as to aid in transferring the heat from the charger.

The charger is self regulating itself to protect its circuitry.

Artificially cooling the heat sensor would be like installing a higher amperage circuit breaker or higher amperage fuse to a circuit in which case one could overload the circuit causing melting and shorting.

[billknny]

Hey everybody...

A battery charger's temperature compensation should work not by altering the charge current, but rather the voltage, typically lowering it by about 24 millivolts per degree C above 25C, although the exact number should be specified by the battery manufacturer.

If you set the absorbtion voltage to 14.4 Volts, for example, it would drop to

14.4 - (0.024 * 10) = 14.16V at 35C

Or rise to 14.64 Volts at 15C

Currents are unaffected by this adjustment, except as needed to reach the voltages.

Some chargers do have circuits to cut back on the current output of the charger based on the CHARGER'S internal temperature, but that is a different issue and typically doesn't happen until temperatures are quite hot, 40C or more. It can be an issue if the charger has forced air cooling and the fan has failed.

[Montanan]

From the operating manual of the CTEC 300

Note that ambient temperature near the battery is a key control metric. The other is a time dependent metric as to whether the charger has cycled from constant voltage to constant current [reduced current], or maintenance. It very well could be that your 25 Amp peak charger simply has shifted to a lower current output stage.

It uses an eight step charging regime.

TEMPERATURE COMPENSATION
M300 has a sensor cable placed together with the battery cables. The units will automatically adjust the charging voltage if the
temperature deviates from +25°C. A high temperature lowers the voltage and freezing conditions is handled by higher voltage.
The temperature is best measured on or very close to the battery. Therefore always place the sensor as close to the battery as
possible when charging. The sensor cable could be prolonged or cut to length with the same functionality. Activated temperature
sensor will be indicated by a lit temperature sensor indicator lamp. The charging voltage is then adjusted to the +25°C condition.
SPECIFICATION
Model 1013
Voltage AC 170–260VAC, 50–60Hz.
Charging voltage 14.4V
Charging current 25A max.
Current, mains 2.9A rms (at full charging current)
Back Current Drain* <2Ah per month
Current ripple** <4%
Ambient temperature -20°C – +50°C Output power is automatically reduced at higher temperatures.
Cooling Fan
Charger type Eight-step, fully automatic
Battery types All types of 12V lead-acid batteries (WET, MF, AGM and GEL).
Battery capacity 50–500Ah
Protection class IP44 (Outdoor use)***

CHARGING PHASES
M300 charges and analyses in eight fully automatic steps. M300 has three different operating modes, see Battery Types and Settings.
The battery charger has an 8-step fully automatic charging cycle:

Desulphation
Desulphation with pulses recovers sulphated batteries. Indicates with lamp 1.

Soft start (Lamp 1)
Start mode for the charging cycle. The start phase continues until the battery’s terminal voltage has risen above the set limit, at which
point the charger switches to bulk charging. If the terminal voltage has not passed the voltage limit within the time limit, the charger
switches to fault mode (lamp 0) and discontinues the charging. If so, the battery is faulty or its capacity is too large.

Bulk (Lamp 2)
Main charge when 80% of charging takes place. During this stage, the charger delivers maximum current until the terminal voltage has risen to the set
level. Bulk has a maximum time, at which point the charger automatically switches to Absorption.

Absorption (Lamp 3)
Complete charge up to virtually 100%. The terminal voltage is maintained at the set level. During this phase the current tapers
successively. Once the current has tapered to the set limit, this phase switches to being timed. If the total time for Absorption exceeds
the time limit the charger automatically switches to maintenance.

Analysis (Lamp 3)
Testing self-discharge. If self-discharge is too high, charging is discontinued and fault mode is indicated.

Maintenance charging - Float (Lamp 4)
Charging at constant voltage.

Maintenance charging - Pulse (Lamp 4)
Charging varies between 95% and 100% state of charge. The battery receives a pulse when the voltage drops and keeps the battery
in perfect condition when it is not in use. The charger can be connected for months at a time. The charger continuously measures the
terminal voltage to determine whether a charging pulse should be initiated. If the battery is loaded and/or the battery’s terminal voltage
drops the charger starts a charging pulse until the terminal voltage reaches the set level. The charging pulse is then discontinued and
the cycle is repeated infinitely. If the terminal voltage drops below a lower limit, the charger automatically goes back to the beginning
of the charging curve.

Recond (Lamp 5)
This mode is used to recover deeply discharged flooded batteries. Recondition of deep discharged batteries. The voltage increases
with reduced current for a limited time period. The higher voltage starts some gassing and mixing of the acid, which is beneficial for
both battery capacity and expected life. Note that the battery could emit explosive gas during Recond. Recond is performed between
Analysis and Maintenance.

[4kMike]

Thank you fellows!

My point was the battery temperature sensor and the temperature knee point on 25 degrees. Doesn't that mean that I never get the full charging voltage (and because of that full amperes) when in tropics? My primary charging is solar, and secondary main engine, but it would be nice to get that 20-25 amps when running genset too. Of course without boiling batteries.. ;-)

[Montanan]

There appear to be three factors:

The temperature compensation sensor limiting voltage at temperatures of 25 degrees C and above.

The main charge / "bulk", constant current stage becoming completed. The main charge, constant current mode is when 80% of charging takes place. During this stage, the charger delivers maximum current until the terminal voltage has risen to the set level, or the Bulk staging achieves its maximum time limit, at which point the charger automatically switches to Absorption.

Absorption (Lamp 3)
During this stage the battery complete charge up to virtually 100%. The terminal voltage is maintained at the set level. During this phase the current tapers successively as the battery voltage increases and becomes ever more near equal to the charger's set voltage level. Once the current has tapered to the set limit, this phase switches to being timed. If the total time for Absorption exceeds the time limit the charger automatically switches to maintenance mode.

[Montanan]

You may consider upsizing your charger.

FEATURES
Smart alternator compatible
Delivers 120A for quick recharge of batteries 28–500Ah
Compatible with D250SA and D250SE for the ultimate 140A power management solution
Prioritizing critical consumers and supplies consumers directly from the alternator
Start assistance function
SMARTPASS 120S charges and supplies the service battery and equipment with 120A, separates critical equipment from non-critical equipment ensuring that radio, emergency lights and navigation systems always have power.

SEPARATE, PRIORITIZE AND BOOST BATTERIES AND EQUIPMENT

SMARTPASS 120S is a 120A Power Management Solution which distributes, controls and maximizes the available energy from your alternator to power service batteries and consumers. SMARTPASS 120S handles all 12V batteries between 28–800Ah. The SMARTPASS 120S’s Battery Guard function ensures that critical equipment such as radio, emergency lights and n avigation systems always have power and take priority when the voltage on the service battery is low disconnecting non-critical consumers. The unit’s Battery Guard will protect your service battery from total discharge and built in over temperature protection reduces charge current before the battery temperature gets too high. SMARTPASS 120S is compatible with the D250SA and D250SE 20A on board chargers.



TECHNICAL SPECIFICATIONS
Input

11.5–23V, Max 120A (350A temporarily for 10 seconds)

Output

Max. 120A (350A temporarily for 10 seconds)

Back current drain

Less than 7Ah/month

Ambient temperature

-4°F to +122°F (-20°C to +50°c)

Battery types

12V: WET, EFB, Ca/Ca, MF, AGM, GEL, LiFePO4

Battery capacity

28–800Ah

Insulation Class

IP65 (splash and dust proof)

Warranty

2-year warranty

https://smartercharger.com/collectio...smartpass-120s

https://cdn.shopify.com/s/files/1/01...07522301633849

[billknny]

Originally Posted by 4kMike

Thank you fellows!

My point was the battery temperature sensor and the temperature knee point on 25 degrees. Doesn't that mean that I never get the full charging voltage (and because of that full amperes) when in tropics? My primary charging is solar, and secondary main engine, but it would be nice to get that 20-25 amps when running genset too. Of course without boiling batteries.. ;-)

Not exactly.

A battery is fully charged at a lower voltage when it is hot. This is a basic function of the chemistry going on inside. Do not think of it as undercharging at higher temperatures.

[Montanan]

Or you could just put your boat into Flathead Lake here in Montana, the present temperature of the water is a balmy 47 degrees F / 8.3 degrees C.

Warming quickly soon to be inviting a swim.

[Sailmonkey]

Originally Posted by Montanan

Or you could just put your boat into Flathead Lake here in Montana, the present temperature of the water is a balmy 47 degrees F / 8.3 degrees C.



Warming quickly soon to be inviting a swim.

If the present daytime temperatures keep up it’ll be swimming time sooner than later!

[Montanan]

Originally Posted by Sailmonkey

If the present daytime temperatures keep up it’ll be swimming time sooner than later!

Amazing, on Leapday, it was sunny and 61 degrees. Unheard of warmth for this time of the year. The lake looked very inviting, albeit the water is still lowered to its winter level and will rise by about 10 feet to be at full pool by the end of May. Indeed early swimming should soon occur, typically one waits until late April or early May to go dipping. My wife and I like to venture out so as to be the the first sailboat on the lake for the year on my birthday, May 2nd. This is a historically warm year. The water temperature on May 2 has usually warmed to about 40 degrees, not much fun to wade in to launch the sailboat and to recover on the trailer but with today's temperature being 47 degrees it would be much easier to venture out into. So yea, the next warm day, we will launch one of our sailboats and cross the lake.

Last year during the winter the lake froze completely over the first time in over thirty years. This year there was no icing to speak of. The lake is the largest freshwater lake west of the Missouri River and is subalpine at just under 3,000 feet in elevation. The lake is bordered on its eastern shore by the Mission Mountains and on the west by the Salish Mountains. The mountains are presently very deeply snow bound.

Flathead Lake is one of the cleanest and clearest lakes in the populated world for its size and type. It is approximately 30 miles (48 km) long and 16 miles (26 km) wide, covering 197 square miles (510 km2). It is a similar size as Minnesota's Mille Lacs Lake. It is about half the area of San Francisco Bay (main bay). It is larger in surface area than Lake Tahoe. Flathead Lake has 161 miles of shoreline to explore and a maximum depth of 370.7 ft (113.0 m), and an average of 164.7 ft (50.2 m). This makes Flathead Lake deeper than the average depths of the Yellow Sea or the Persian Gulf.

Flathead Lake is my primary summer sailing place and is an exceptionally scenic part of Montana, 30 miles (48 km) southwest of Glacier National Park and is flanked by two scenic highways, which wind along its curving shoreline.

Some images shared below. We have our second residence on the southend of the lake, in the town of Polson, the primary town on the lake, and the County seat, with a population of about 4,500. Can be located at the bottom of satellite photo adjacent to where the Flathead River exits the lake. The southern half of the lake is located in the Flathead Nation, of the Confederated Salish and Kootenai Tribes. The image with the mountains is looking across Polson Bay to the Mission Mountain range, which rise about 3,500 feet above the lake and are wilderness.

[4kMike]

No thank you Montanan: we have just been sailing 9 months south from Helsinki Finland. That is on the same latitude with Greenland. :-D. We do have the central heating and sauna on board. No use for them for a while, I hope...

[Montanan]

Originally Posted by 4kMike

No thank you Montanan: we have just been sailing 9 months south from Helsinki Finland. That is on the same latitude with Greenland. :-D. We do have the central heating and sauna on board. No use for them for a while, I hope...

Wow, not a lot of sunlight that far north in the winter months and I suspect could be quite cold. Would love to charter a boat in the summer months there with the really long days. Very beautiful archipelago sea to explore and camp.

We like cool weather, do not have heat or AC on the boats here. During the winter the boats are hauled out and on the hard under tarps. No AC in the homes either.

During winter if we are staying in Montana we will typically warm our homes up to 63 F / 12 C during the day then let it cool in the early evening so as to be about 50 F / 10 C during the night. In the summer we like to let the house be at the ambient temperatures, at night that usually is in upper 40's / 8.5C by leaving the windows or wide doors open at night so as to allow sleeping comfortably. The problem with leaving the doors open at night is that critters tend to walk in, neighbor cats for the most part. My dogs would chase them out. My wife heard a noise one night and went to see what it was, found a skunk, nosing about the bag of dog food in the pantry. They both parted separate ways. Our dogs slept through that home invasion. So far the deer, bear [no Grizzlies yet, just Blacks], mountain lions and coyotes have not entered the home instead just traversing through the yard and venturing up to the edge of the porch and patio. When sailing or at anchor we do see the occasional deer and bear swimming across the lake, generally traversing between islands to and from a peninsula. They will swim for miles.
When we go to a tropical climate [generally during our winter] it takes a while to get used to the comparatively high heat, e.g. 80+ F, and the humidity. We tend to wilt.

Seems in the Spring in Montana that kids start walking about in shorts and t-shirts when it gets to be about 32 F / 0 C and is sunny. I have seen my daughter when she was a youngster walking through a bit of snow to go swimming in the lake early season; she never seemed to mind the chill and would swim for considerable time, so not me; always hoping she would not need me to go into the cold lake to rescue her. I recall a winter get away trip in early January to Disney World in Florida, my daughter and I spent one of the days at the huge water park, we were almost the only persons in the entire water park, it warmed to perhaps the upper 50's at the peak of the day, very pleasant temperature for water slides, wave pools, floats and swimming for Montanans. She in her bikini and I in swimming shorts. No lines, no crowds, no one except the employees for the most part. The water park employees were shivering and bundled up in sweaters and sweat pants. We felt very spoiled to experience the water park when there was no one else. It would be a mad house in the summer. Sort of like experiencing the lakes in Montana when there typically is no other boats in eyesight.