AC DC Adaptor fail

[DiyNutJob]

Here are two styles of car charging cables. For a car that shuts off the cigarette lighter while in sleep mode, the ODB2 port can be used. Both cables are protected by 750-800mA fuse, in additional to the car's own protection fuse. Each cable has two charging connectors, one for a perma-placed solar panel, and the other for the to-be-developed portable charger.

 

[DiyNutJob]

Happy news for excitement seekers! Live testing of the portable charger has gone ahead and it appears to work as intended. The car battery is receiving 60mA charge nett of the car's sleep consumption. I am using the tried and tested old controller for this while the new controller is still waiting to be tested and an enclosure to be 3d designed for it. Currently running the old controller without additional 250mA fuses for protection. We all know car batteries have a lot of power and the controller could be zapped by 2 batteries.

 

[DiyNutJob]

The final prototype of the charger controller is ready. The controller is protected by 250mA fuses on the power in and power out sides. This will make it safe as houses while playing with unattended battery charging. I could use lower rated fuses if I had them.

The socket is the power-in, lead is power-out, and the side air vents double up as a window to the status LEDs: blue=charging, green=full, red=amperage output at limit. I believe the LEDs consume 10mA each, and are power parasites for the car and/or charger. There are vents on the lid. I don't anticipate a lot of heat: 12.8v * 0.150A = 2W max + wastages. The enclosure is made from PETG, using a £90 new BIQU Hurakan china printer, that was on offer on ebay.

 

[Mottie]

The final prototype of the charger controller is ready. The controller is protected by 250mA fuses on the power in and power out sides. This will make it safe as houses while playing with unattended battery charging. I could use lower rated fuses if I had them.

But but but but won’t this affect your insurance or have you notified your insurance company of what you are doing?

 

[DiyNutJob]

But but but but won’t this affect your insurance or have you notified your insurance company of what you are doing?

We don't talk about the insurance in this thread.

 

[DiyNutJob]

Bull ox. The new controller turned out to be step down only controller. So they gave me a refund while I keep the useless junk, even though I was partially at fault for buying the wrong thing. I could use them to slow down PC fans. But I have plenty of PWM's already that are more energy efficient. This controller lights up like a christmas tree and eat up all my electricity.

 

[Mottie]

We don't talk about the insurance in this thread.

Makes a change for you - you talk about it constantly in other threads.

 

[DiyNutJob]

The portable charger is viable. By deep cycling the charger battery, I may be able to get 1 month or more of unattended charging/tendering time out of it. The minimum voltage the controller needs is 4.8V. This allows extraction of all available power from the charger battery.

FEB-05
charger: 12.8V, 150mA open circuit
Charger battery: Type 075, 320/440CCA, 53% life, 8.1 mOhm, 12.81V, in idle low-rate self discharge
Car battery: Type 027, 520/600CCA, 75%, 4.99 mOhm, 12.35v, either or both terminals connected to car.
Car battery: 529CCA, 78%, 4.9 mOhm, 12.39v, stand alone
Car voltage: 12.42V rising, chargers(incl solar) connected

FEB-11
Charger battery: 284CCA, 42%, 9.1 mOhm, 12.54V
Car battery: 518CCA, 75%, 5.01 mOhm, 12.61V, connected to car
Car battery: 519CCA, 75%, 5 mOhm, 12.61V, stand alone
Car voltage: 12.73V, chargers connected

FEB-23
Charger battery: 234CCA, 28%, 11.08 mOhm, 12.27V
Car battery: 528CCA, 78%, 4.91 mOhm, 12.55V, connected to car
Car voltage: 12.67V, chargers connected

Notes:
320/440CCA means 320 out of estimated/actual maximum 440.
Car battery status measured at the battery terminals.

The fact that the car battery did not lose charge means the burden of the car's sleep consumption was taken by the charger. The battery not gaining any charge since the start of charging is acceptable. This leaves capacity open for charging by the alternator when the car is driven. If the voltage and/or amperage of the charger is raised, this should result in the battery gaining charge. I see no reason for that at the moment as things appear in equilibrium.

 

[DiyNutJob]

Here's the production version of the charge controller, based on the step up down DC converter I was using before. I have 3 units, 2 for in car use. Use of ethernet wires limits the maximum capability to 2 amps. For the in car units, these are protected by 250mA fuses on the supply and output sides.

 

[DiyNutJob]

The charger battery becomes a fridge during discharge and condenses air moisture into water. This will have to be dealt with by padding it with a thick towel. Water is pooling at the base as well as on the "ledge" below the top.

 

[Harry Bloomfield]

The charger battery becomes a fridge during discharge and condenses air moisture into water. This will have to be dealt with by padding it with a thick towel. Water is pooling at the base as well as on the "ledge" below the top.

To avoid you disappearing down another 'rabbit hole' - batteries produce heat, both during charge, and discharge. What you are seeing is simple condensation, due to high moisture levels, and a battery cooler than its environment. It was perhaps very cold overnight, the cold will linger, due to the large batteries mass.

 

[DiyNutJob]

You need to keep with the times. Google AI:

AI Overview
Learn more

Yes, a battery can get cold when it discharges, especially in cold environments, because the chemical reactions happening inside the battery that produce electricity also generate heat; when the battery is discharging, these reactions slow down, leading to a drop in temperature.

Key points about battery discharge and temperature:

• Chemical reaction slowdown:
  When a battery discharges, the chemical reactions within it slow down, resulting in less heat generation and a drop in temperature.
  
  
• Cold weather impact:
  In cold weather, the already slowed-down chemical reactions in a discharging battery can be further hampered, leading to a more significant temperature drop.
  
  
• Reduced capacity:
  Cold temperatures can also reduce the overall capacity of a battery, meaning it will not be able to deliver as much power before fully discharging.

 

[Jurassicspark]

Why would you ask AI???

 

[bernardgreen]

AI Overview
Learn more

A lead acid battery generates heat primarily during charging and discharging, with the most significant heat production occurring at the end of a discharge cycle and the beginning of a charge cycle; this heat is a result of internal resistance within the battery, causing "Joule heating" as current flows through it, and is influenced by factors like the charging current and the battery's state of charge.

Key points about heat generation in lead acid batteries:

• Charging process:
  The most noticeable heat generation happens during high-rate charging, especially near the end of the charge cycle when the battery reaches its full capacity.
  
  
• Discharging process:
  Significant heat can also be produced during heavy discharge, particularly at high current draws.
  
  
• Internal resistance:
  The primary factor causing heat generation is the internal resistance of the battery, which increases with higher current flow.
  
  
• Float charging:
  Even during float charging (a maintenance charge at a low current), a small amount of heat is still produced.
  

Factors affecting heat generation:

• Charging current: Higher charging currents lead to greater heat generation.
  
  
• Battery temperature: Higher ambient temperatures can further increase heat production within the battery.
  
  
• Battery age: Older batteries may experience increased internal resistance and thus generate more heat.
  

Potential issues with excessive heat:

• Reduced battery life:
  High temperatures can accelerate the degradation of lead plates within the battery, shortening its lifespan.
  
  
• Electrolyte loss:
  Excessive heat can lead to increased water evaporation from the electrolyte, potentially affecting battery performance.
  
  
• Thermal runaway:
  In extreme cases, excessive heat can trigger a thermal runaway reaction, causing a rapid increase in temperature and potential damage to the battery.
  

 

[Harry Bloomfield]

You need to keep with the times. Google AI:

AI Overview

AI changes nothing nor does time - batteries heat up during both charge, and discharge.