I wonder what you think about the following problem: A car's battery needs to be replaced but the exact capacity battery is not available,...

I wonder what you think about the following problem: A car's battery needs to be replaced but the exact capacity battery is not available, though smaller or larger ones are. My feeling is that the battery capacity is matched by the manufacturer with the alternator's charging capacity, so the replacement battery should also closely match the OEM battery's capacity. Is my assumption corre...

Hi, Many moons ago I bought an analog multimeter, and one of its functions was to test batteries. It loaded the battery with a resistor,...

Hi, Many moons ago I bought an analog multimeter, and one of its functions was to test batteries. It loaded the battery with a resistor, drawing some significant current (for three battery types) and then measuring I don't know if voltage or current (typical green-yellow-red zones). Right now it is on another city. So now comes a friend that says the battery for a DECT phone doesn't ...

In terms of battery life, and assuming the same brand of Alkaline battery, is it more efficient to use a 9V battery or 2 AAA cells...

In terms of battery life, and assuming the same brand of Alkaline battery, is it more efficient to use a 9V battery or 2 AAA cells with something like the TL496 converter pictured here. http://www.electroschematics.com/6788/3v-to-9v-dc-converter/ If not, what is the approximate difference either way? The circuit involved is a test audio oscillator. Would be nice if they made mor...

I have a customer who needs a battery-powered system that will operate in any orientation. A car battery is the only thing that has the A-hrs...

I have a customer who needs a battery-powered system that will operate in any orientation. A car battery is the only thing that has the A-hrs he needs (I think). I assume a sealed car battery solves the obvious problem of leaking acid, but are there any other considerations that prevent a car battery from being used when it is upside-down? Are there other types of rechargeable batteri...

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

I recently bought a new MacBook Air. There are all sorts of tips about extending the duration of a single charge. Does it...

I recently bought a new MacBook Air. There are all sorts of tips about extending the duration of a single charge. Does it matter when I charge it if I want to get the battery's life to be the longest? Should I charge it when the battery is at 50%, 25%, or maybe let it run down to shutdown?

http://citylabs.net/ Looks like betas whacking solar cells. Makes no sense to me. A primary lithium battery will deliver power for over...

http://citylabs.net/ Looks like betas whacking solar cells. Makes no sense to me. A primary lithium battery will deliver power for over 20 years at a cost per joule probably a million times better than this. Not to mention getting a more sensible terminal voltage. How do they expect to charge a battery with 0.7 volts? That all goes for most of the "energy harvesting" things you read ...

I have a 75332P MOSFET on a cordless drill controller heatsink. I guess it's part of a pulse width modulator. The drain (flange) connects...

I have a 75332P MOSFET on a cordless drill controller heatsink. I guess it's part of a pulse width modulator. The drain (flange) connects directly to one of the battery terminals. Does the MOSFET drain go directly to the battery minus/ground terminal? Or does it go to the battery plus terminal? Thanks. -- My application... I'm desperately trying to develop a better inline ...

I, like many others, have digital calipers that drain the battery while sitting, and have no on/off switch, so the battery must be removed when...

I, like many others, have digital calipers that drain the battery while sitting, and have no on/off switch, so the battery must be removed when not being used. I recall a conversation here some time ago about this and some had found different brands that worked better than others, in this regard. Anyone recall the names of the brands that don't drain the battery? --

I have a little project am trying to design, and I am running into a little difficulty in the concept stage. I have a device that needs to...

I have a little project am trying to design, and I am running into a little difficulty in the concept stage. I have a device that needs to consume essentially zero power when shut off. A few nanoamps is fine. The device uses a 6S LiPo battery that must be monitored during operation to make sure the battery is not discharged beyond critical limits. To this end, the battery is conn

I have a remote control car that has a dedicated control and receiver at some unknown to me frequency. Not bluetooth or wifi. It was a...

I have a remote control car that has a dedicated control and receiver at some unknown to me frequency. Not bluetooth or wifi. It was a Christmas toy. It is a substantial car nearly 18" long. It uses a 8.4v nicad battery that I cannot find and really want to NOT use. I can get the battery specs if needed. The car is on vacation in the mountains right now. lol I want to replace with Li I...

Electric vehicle batteries are about 85% efficient, but the 15% of the energy that you put in that you don't get out has to appear as heat,...

Electric vehicle batteries are about 85% efficient, but the 15% of the energy that you put in that you don't get out has to appear as heat, generated in the battery. The worst case would presumably be during fast charging. One has to wonder whether anybody has built a battery with heat-pipe down the middle, sticking into heat-sink extrusions projecting from either end. Nobody seems to do...

Hi all, Recap- I had the low Cmos Clock Lithium Battery in a computer. I received a Cmos Clock Lithium Battery from China, had some question...

Hi all, Recap- I had the low Cmos Clock Lithium Battery in a computer. I received a Cmos Clock Lithium Battery from China, had some question about the date code. I installed the Cmos Clock Lithium Battery and had the same message low CMOS battery. I order a new one from Mouser and the computer now works properly. Now I'm onto making the computer control some HP equipment via GPIB, whi...

https://spectrum.ieee.org/grid-scale-battery-storage-nickel-hydrogen With gullible lunatics like Flyguy claiming that lithium ion batteries are...

https://spectrum.ieee.org/grid-scale-battery-storage-nickel-hydrogen With gullible lunatics like Flyguy claiming that lithium ion batteries are too dangerous to use. one has to suspect that the guys behind this battery chemistry are spending a bit on propaganda. The interesting bit in the article is the sentence. "Their use of expensive platinum catalysts kept them relegated to spa

I am not planning to do so, just curious... Using a five amp hour 18 V (20 V Max) battery. At 1 million V, that would be somewhere around 3...

I am not planning to do so, just curious... Using a five amp hour 18 V (20 V Max) battery. At 1 million V, that would be somewhere around 3 A for one second? Sounds like a LOT of energy. Thanks.

Seems to me that is an important question, no matter what alleged device protection there is. I would want to know what the highest...

Seems to me that is an important question, no matter what alleged device protection there is. I would want to know what the highest INDIVIDUAL battery temperature is. I would want an alarm when any battery reaches X degrees. Doesn't matter how many batteries there are. The more batteries, the more important for the driver to know what's going on. I suppose they do not keep track of...

Today's NYT describes a nasty fire in an apartment building in Manhattan, started by a bicycle battery. There have been 200 battery-ignited...

Today's NYT describes a nasty fire in an apartment building in Manhattan, started by a bicycle battery. There have been 200 battery-ignited fires in Manhattan so far this year, with six deaths. Unless battery quality improves somehow, buildings will need fireproof vaults for parking bikes and scooters. I see lots of electric scooters and bikes on the streets of San Francisco lately. Some ...

The battery in my phone burned out, so I ordered a replacement from Amazon. Examining the case, I can't find any fasteners. Do I open it...

The battery in my phone burned out, so I ordered a replacement from Amazon. Examining the case, I can't find any fasteners. Do I open it with an oyster knife? -- Rich

Apart from capacitor ESR checking, I use this meter for checking and tracking battery ESRs. Can anyone give me a safe upper voltage...

Apart from capacitor ESR checking, I use this meter for checking and tracking battery ESRs. Can anyone give me a safe upper voltage level opinion for not damaging the meter in this use? I have used it to check 2S Li-ion but could you get away with a 10S (42V) battery or 48V e-bike battery for example? The meter is too useful to damage! Or perhaps a standard capacitor in series would be a ...

I would like to find out how long to charge the above battery. Charger puts out 500 mAh. Thanks.

I would like to find out how long to charge the above battery. Charger puts out 500 mAh. Thanks.