## Charging time for 12 V battery

Started by in sci.electronics.design11 years ago 18 replies

I have a 12 Volt battery, 9.5 Ah that uses a 12 volt charger 1.0 amp. Assuming the battery is completely discharged, is there a way to...

I have a 12 Volt battery, 9.5 Ah that uses a 12 volt charger 1.0 amp. Assuming the battery is completely discharged, is there a way to determine how long to charge ? Thanks, Andy

## Can anyone explain how this battery charger works?

Started by in sci.electronics.design2 years ago 130 replies

https://imgur.com/a/b8l5qKQ Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a...

https://imgur.com/a/b8l5qKQ Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?

## OT: WARNING Landmine on Van Ness, SF (NB 101)

Started by in sci.electronics.design3 months ago 20 replies

Someone dropped a box there. I made a sharp swing to the right to avoid it, and broke my front end. Might have been better to just hit...

Someone dropped a box there. I made a sharp swing to the right to avoid it, and broke my front end. Might have been better to just hit it. The front wheel is shaking with squiring noise. Barely made it to the charger. Waiting for AAA.

## 150W Stirling Engine?

Started by in sci.electronics.design6 months ago 30 replies

I want to try this emergency battery charger: https://www.ebay.com/itm/185836877680 150W output? Or do they mean 150W LED bulb? Perhaps...

I want to try this emergency battery charger: https://www.ebay.com/itm/185836877680 150W output? Or do they mean 150W LED bulb? Perhaps 10W real output? What's the benefit of twin cylinders vs. the single cylinder version?

## Only one EV charger at home?!

Started by in sci.electronics.design2 weeks ago 1009 replies

https://www.smarthomecharge.co.uk/features/do-you-need-two-home-charge-points-if-you-have-two-evs/ "Some products will have the ability to...

https://www.smarthomecharge.co.uk/features/do-you-need-two-home-charge-points-if-you-have-two-evs/ "Some products will have the ability to âload shareâ, which means they will communicate with each if two vehicles are plugged in. In this scenario, they will evenly split the power available so both cars charge at the same rate, but this will be at around 3-3.6kW â

## Lead-acid charger/starter

Started by in sci.electronics.design11 months ago 12 replies

The "charge" functions are pretty easily understood. But, is the "engine start" function just a whopping big transformer-rectifier-filter...

The "charge" functions are pretty easily understood. But, is the "engine start" function just a whopping big transformer-rectifier-filter sitting behind the clamps? I'm speaking of the ~200A load current devices, not the smaller 50A; something along the lines of:

## Lead Acid puzzle

Started by in sci.electronics.design3 years ago 34 replies

Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I'm not clear what's...

Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I'm not clear what's gone wrong. The charger in use has been a cheap chinese one with 2x13.7v=27.4v output. Single stage charging only. It has always been promptly charged after use, and never run below 50% charge. I checked the battery voltages after charge, they wer...

## DOE Secretary Granholm TRIED to drive an EV cross country...

Started by in sci.electronics.design2 weeks ago 4 replies

...but it proved to be A LOT more difficult than she bargained for, EVEN with her staff BLOCKING EV charging...

...but it proved to be A LOT more difficult than she bargained for, EVEN with her staff BLOCKING EV charging stations: https://electrek.co/2023/09/11/ev-driver-calls-cops-energy-secretary-after-blocks-charger-ice-ca r/ When you force a young mother and her baby to WAIT while your political stunt proceeds, this can only be described as a PR NIGHTMARE! This is just another example of rules for T

## Fun with EV to Vegas

Started by in sci.electronics.design11 months ago 14 replies

North bound at Mountain Pass is out. No problem, i'll drive pass the center media to the south bound charger. I wonder if that would damage my...

North bound at Mountain Pass is out. No problem, i'll drive pass the center media to the south bound charger. I wonder if that would damage my tires. OK, i'll bring the tire repair patch with me. https://www.plugshare.com/location/308971 Plugshare doesn't even know about the up-coming EA and Evgo stations at Primm. I wonder if they will let me tap into the high voltage transformer at the c...

## Inverters vs wallwarts

Started by in sci.electronics.design1 year ago 55 replies

I'm setting up a UPS for my computer/comms equipment using an inverter/charger and battery from Amazon. The equipment draw is only about 40...

I'm setting up a UPS for my computer/comms equipment using an inverter/charger and battery from Amazon. The equipment draw is only about 40 watts measured with a Kill-A-Watt, but all the associated wallwarts use capacitive-input switching power supplies. That means they only draw current at line peaks. My seat-of-the-pants guess is that the duty cycle is around 10%, meaning that the aver...

## MPPT chargers dying upon battery disconnect?

Started by in sci.electronics.design8 months ago 16 replies

Attention, this is one of those rare electronics-related questions :-) Will be rigging up a small power-failure backup system. Essentially a...

Attention, this is one of those rare electronics-related questions :-) Will be rigging up a small power-failure backup system. Essentially a 12V LiFePO4 battery (with BMS in there), inverter, solar panels, MPPT charger. When reading up on stuff and talking to people I found something very disconcerting. It seems that MPPT charge controllers can and often do commit suicide when operat...

## How do UPS trigger circuits work?

Started by in sci.electronics.design5 months ago 19 replies

After using a pair of inverter/charger circuits as UPS units for some months I've become curious as to how the trigger decides when to switch...

After using a pair of inverter/charger circuits as UPS units for some months I've become curious as to how the trigger decides when to switch from line power to the battery and inverter. Supposedly they trigger on wrong voltage or frequency, but they do it in less than a half-cycle, so it seems to be more than a simple relay. A cursory web search found nothing but I don't know the proper...

## USB charger circuit

Started by in sci.electronics.design10 years ago 20 replies

I am working on a simple USB charging circuit. Normally, the 3.6V NiMH bat= tery is connected to the device via the NC contacts of a relay. ...

I am working on a simple USB charging circuit. Normally, the 3.6V NiMH bat= tery is connected to the device via the NC contacts of a relay. When conne= cted, a 5V relay switch the battery to charge via a diode. So, a fully char= ged battery is around 4.2V. As someone suggested, i will put a parallel R = & C to reduce the hold current of the relay.=20 Questions: 1. What is the minimum ...

## Solar panel example for LT-Spice?

Started by in sci.electronics.design2 years ago 7 replies

I'm working on a TP4056-based 1S LIPO solar charger which includes a load sharing (aka power path) function. But I don't have a panel to test...

I'm working on a TP4056-based 1S LIPO solar charger which includes a load sharing (aka power path) function. But I don't have a panel to test with. So I'd like to simulate the circuit in LT-Spice. But I've never used spice, LT or otherwise, so I was hoping to find an example of a solar panel equivalent circuit that I could import, then add the rest of the circuit, which is pretty simpl...

## Trans Sec Buttigieg calls EVs "generators"

Started by in sci.electronics.design11 months ago 16 replies

https://www.cnsnews.com/article/national/susan-jones/buttigieg-electric-vehicles-could-be-very-useful-during-power-outage Of course, EVs don't...

https://www.cnsnews.com/article/national/susan-jones/buttigieg-electric-vehicles-could-be-very-useful-during-power-outage Of course, EVs don't "generate" anything, they are just a big battery. At best, they can be called a "reserve power source." Of course, once you have drained the EV's battery it won't MOVE. Using it as a power source means it must be connected to the charger whic

## new 30MHz to 300MHz switcher - worlds smallest laptop adapter

Started by in sci.electronics.design10 years ago 64 replies

Hi, Here's a new SMPS switcher apparently coming out next year for...

Hi, Here's a new SMPS switcher apparently coming out next year for laptops: http://phys.org/news/2013-12-circuit-laptop-charger-brick.html It apparently has a "power reclaiming scheme" for higher efficiency, would this be conventional sync rectification or some other thing? It looks like power electronics is in for a big (r)evolution once the 300MHz+ designs start to spread! cheer...

## MC34063 Step-down Converter Heating Problem

Started by in sci.electronics.design12 years ago 21 replies

Hi, I have constructed a DC-DC step-down converter using the MC34063. The circuit I use is very similar to the one shown...

Hi, I have constructed a DC-DC step-down converter using the MC34063. The circuit I use is very similar to the one shown here: http://www.eleccircuit.com/wp-content/uploads/2008/01/ipod-mp3-player-charger-by-mc34063.jpg My circuit does not have the Zener, output side LED and input side protection diodes (TVS1 and D2 in the circuit). The rest of the circuit is quite similar. The...

## Motion in support or reject EV charging chip reader?

Started by in sci.electronics.design2 years ago 90 replies

Again: "Cost - \$700 million in costs could slow EV charger deployment across California. By CARBâs own calculation, an EMV chip reader...

Again: "Cost - \$700 million in costs could slow EV charger deployment across California. By CARBâs own calculation, an EMV chip reader mandate will add approximately \$3,000 to the cost of a charging station over its lifetime - \$371 for the hardware and \$270/year in operations and maintenance (O&M) costs" http://www.evassociation.org/carb.html For: 1. Allow simple an