Cooling an electric vehicle battery.

Started by Anthony William Sloman in sci.electronics.design1 year ago 52 replies

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...


Better buy a new multimeter then a new battery!

Started by Jan Panteltje in sci.electronics.design14 years ago 49 replies

I was at the hardware store, needed some screws, other stuff. Found a 5 Euro digital multimeter with transistor hfe test for 5 Euro. .5%...

I was at the hardware store, needed some screws, other stuff. Found a 5 Euro digital multimeter with transistor hfe test for 5 Euro. .5% accuracy on DC it says. Did not need it, but could not resist. Took it home, did not expect it to have a battery in it, for that price. But it did, and it was new and full.... Looked up the price of a new 9 V battery on conrad.nl: 4 Euro 9 cents http://ww...


Error message on GPIB program, Help

Started by amdx in sci.electronics.design8 years ago 33 replies

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...


OT: How to avoid smartphone battery damage from always being plugged in and topped off

Started by John Doe in sci.electronics.design2 years ago 33 replies

Ima try using a lower power USB wall adapter. Was using 2 A at 5 V. Will try a 1 A at 5 V adapter. The battery was getting quite warm,...

Ima try using a lower power USB wall adapter. Was using 2 A at 5 V. Will try a 1 A at 5 V adapter. The battery was getting quite warm, apparently every time the smartphone felt the need to recharge it, hopefully not due to overcharging. Now, with the 1 A USB adapter, seems the battery is cool even though it's charging. Won't mess with it if it doesn't get warm again. Being able to sp...


Using cordless drill battery as stun gun?

Started by John Doe in sci.electronics.design5 years ago 27 replies

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.


OT: Do electric cars let you monitor INDIVIDUAL battery temperature?

Started by John Doe in sci.electronics.design5 months ago 30 replies

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...


lithium fires

Started by John Larkin in sci.electronics.design4 weeks ago 32 replies

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 ...


replacing a battery

Started by RichD in sci.electronics.design1 year ago 10 replies

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


Charging time for Ultrafire 18650 6800 mAh battery

Started by Andy in sci.electronics.design4 years ago 44 replies

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.


RTC and cr2032 low voltage

Started by captoro in sci.electronics.design11 years ago 2 replies

Hi, I am using the RTC DS1337 with a CR2032 battery. I know that when these battery shows 2.7v, it needs replacing, Although the RTC can...

Hi, I am using the RTC DS1337 with a CR2032 battery. I know that when these battery shows 2.7v, it needs replacing, Although the RTC can go down to 1.4V from the spec sheet. I even powered it through my power supply at 1.1V and it was keeping time correctly. I am only power the RTC from the battery. My question is : How low of a voltage can I go before replacing in a real life situation ? ...


Battery problems

Started by Don Y in sci.electronics.design8 months ago 29 replies

Does anyone *know* what cause(s) of recent/historical battery fires (in EVs, particularly)? I assume it is not related to abuse or "usage...

Does anyone *know* what cause(s) of recent/historical battery fires (in EVs, particularly)? I assume it is not related to abuse or "usage hazards". Or, charging/BMS. But, rather, originates in manufacturing (?) Is this an issue with material (im)purities, mechanical defects, assembly faults, etc.?


Filter Cap for a battery pack ?

Started by Sid 03 in sci.electronics.design12 months ago 5 replies

I need to select a capacitor for a battery pack. I see a lot of circuits that use Alkaline batteries and then have a ceramic capacitor across the...

I need to select a capacitor for a battery pack. I see a lot of circuits that use Alkaline batteries and then have a ceramic capacitor across the leads of the series battery pack to act as a filter. My question is how do you size the cap ? I hate just looking at what someone else has done and just guess or copy. I have 4x 1.5v alkaline batteries in series powering a amplifier circuit. ...


PNP for soft switch and reverse battery protection

Started by Peabody in sci.electronics.design6 years ago 66 replies

I'm working on a small circuit that will be powered by a 9V battery. I would like to combine the functions of a soft power switch and reverse...

I'm working on a small circuit that will be powered by a 9V battery. I would like to combine the functions of a soft power switch and reverse battery protection in a single device. I think the answer may be to use a PNP transistor on the high side, with a base resistor to ground - actually to ground through a physical momentary switch, or indirectly to ground via an NPN transistor cont...


battery charger

Started by RichD in sci.electronics.design1 year ago 5 replies

I picked up a AAA NiMh battery charger. The label reads: Output: 1.2 V 800 mA AA/AAA charging: 120 mA Why the two different current...

I picked up a AAA NiMh battery charger. The label reads: Output: 1.2 V 800 mA AA/AAA charging: 120 mA Why the two different current specs? Does not compute - -- Rich


NiCd cell replacements

Started by Andy K in sci.electronics.design9 years ago 14 replies

I will be replacing eight cells in a battery for a cordless drill. 9.6 V The markings did not lead anywhere. DF21NF NiCd Since there are...

I will be replacing eight cells in a battery for a cordless drill. 9.6 V The markings did not lead anywhere. DF21NF NiCd Since there are eight cells in the battery, I think they are 1.2 volt nicads. 1 3/4 X 5/8 are the dimensions if that would help with determining the mAH. Could someone help me in what would be a good replacement ? Thanks.


Charger recommendations

Started by Andy in sci.electronics.design5 years ago 17 replies

I am looking at the Nitecore D4 Digicharger/Four Channel Universal Smart Battery Charger/LCD Display and GYRFALCON All-44 4 Channel Digital...

I am looking at the Nitecore D4 Digicharger/Four Channel Universal Smart Battery Charger/LCD Display and GYRFALCON All-44 4 Channel Digital Battery Charger. What do you recommend ? I read where 26650 have a higher capacity than 18650s. Andy


HP3586 Selective Voltmeter Help

Started by amdx in sci.electronics.design5 years ago 1 reply

I bought an HP3596B off Ebay. I have a service manual on order. First thing I did was remove the leaky battery and thoroughly clean the PS...

I bought an HP3596B off Ebay. I have a service manual on order. First thing I did was remove the leaky battery and thoroughly clean the PS board. It looks good, however if I look down to the edge connector inside the unit I can see it has the blue buildup on it from the battery leak. I'll save that until I disassemble to clean and lube the switches. At power up the self calibrati...


Re: Battery Difference between CR2032 and CR2025

Started by Sjouke Burry in sci.electronics.design2 years ago 77 replies

fred.flintstone@thecave.com wrote in news:a0fa48poski1u7imevrk3jviugam1if5qc@4ax.com: > My computer clock battery died. It had a CR2032. I...

fred.flintstone@thecave.com wrote in news:a0fa48poski1u7imevrk3jviugam1if5qc@4ax.com: > My computer clock battery died. It had a CR2032. I bought a CR2025 at > a store going out of business (No Returns). Both say they are 3v. The > CR2025 is a little thinner, but otherwise they are the same size. Is > there any reason not to use the 2025? > > -------------- > > To thin to fi


DC Voltage level sensing

Started by Cursitor Doom in sci.electronics.design3 years ago 141 replies

Greetings, Gentlemen, What's the simplest way of implementing this: The 'quiescent voltage' (so to speak) of a car battery is typically...

Greetings, Gentlemen, What's the simplest way of implementing this: The 'quiescent voltage' (so to speak) of a car battery is typically 12.4V. With the engine running, however, this rises to 14V due to the charging current from the alternator. How most reliably to sense when the battery voltage exceeds 13V so a dashcam can be activated? -- This message may be freely reproduced...


SLB and charger question

Started by Andy K in sci.electronics.design9 years ago 3 replies

I would like to buy a NP 4-6 Yuasa 6 Volt 4 Amp Hour Battery. Would this charger work and how do I determine how long to recharge a discharged...

I would like to buy a NP 4-6 Yuasa 6 Volt 4 Amp Hour Battery. Would this charger work and how do I determine how long to recharge a discharged battery ? Model: HB-0702-01 Input: AC100-240V 50-60Hz 0.2A Output: DC7.2V 1.0A I would be powering some led lights that operate at 3.0 volts, so I would need to find out how to step down the voltage as well. Thanks.