My trusty old Russky meter died and I can't be sans analog meter for long. Must be cheap and simple because they get dropped, crushed,...

My trusty old Russky meter died and I can't be sans analog meter for long. Must be cheap and simple because they get dropped, crushed, snatched, whatever. Has anyone used the HM-102S while in the service? https://www.amazon.com/SOLTEC-HM-102S-Analog-Multimeter-VOLTS/dp/B01M1ETSF9 Why do these need a 9V battery? At 20k/V input impedance that just doesn't make sense. -- Regards, Joe...

Hi there, I need some help in making a very basic unit, which consists of 3 x AA battery holder 4.5v, Toggle switch, L.E.D light, 1 meter cable ...

Hi there, I need some help in making a very basic unit, which consists of 3 x AA battery holder 4.5v, Toggle switch, L.E.D light, 1 meter cable with opposing crocodile clips + & - (red and Black) this needs to be set in an White ABS Plastic waterproof box. I need 50 units built once the design and sample box has been inspected. any upgrades are welcome like use of different on/off switch f...

There has been conjecture here about lithium battery ignition, thermal runaway, and whether any measurements could provide useful warning of a...

There has been conjecture here about lithium battery ignition, thermal runaway, and whether any measurements could provide useful warning of a possible cell explosion. Waiting for my biscuits to cook, a (very) little research turns up not much about failure dynamics. Most studies measure external cell temperature as indicators of thermal runaway. I found one study, from NREL, that used f...

I am using these batteries. Discharging from the (BMS managed side) 8 pins connector seems OK, but charging is not working. It might need the I2C...

I am using these batteries. Discharging from the (BMS managed side) 8 pins connector seems OK, but charging is not working. It might need the I2C control to enable charging? With the battery at 10V, hooking up a 11V supply doesn't seem to do any thing, with the voltage coming up to 11V immediately. Someone reported good result with 12V+ adjustable supply. Hooking up to the inte

I have two Harbor Freight digital calipers, item #47257, and I've had=20 problems with one of them especially, where the display will go blank....

I have two Harbor Freight digital calipers, item #47257, and I've had=20 problems with one of them especially, where the display will go blank. = It=20 seemed to work sometimes if I squeezed the enclosure, and I thought it = was a=20 bad battery or bad connection. But a fresh battery didn't work. So I took it apart, which meant peeling off a foil backing to expose = four=20 small phillip...

The Daly-Antra types of BMS (Battery Monitor Switch) require charging current before they'll turn on. Unfortunately, most 'smart'...

The Daly-Antra types of BMS (Battery Monitor Switch) require charging current before they'll turn on. Unfortunately, most 'smart' inverter/chargers won't turn on until the battery is connected, so guess what happens when a Daly-Antra BMS is used? Nada. That's what happens when a Daly-Antra . . . . They supply a Blue-Tooth dongle that plugs into their UART port, for remote monito...

Hi all, I have a device which is powered by a solitary 1.2V 800 mA NiCd cell. An AC wall charger (5VAC @ 180 mA) is used to charge the cell. ...

Hi all, I have a device which is powered by a solitary 1.2V 800 mA NiCd cell. An AC wall charger (5VAC @ 180 mA) is used to charge the cell. This is done via a simple half-wave rectifier that is built in to a small circuit board inside the device. The battery sees about 90 mA (true RMS). It seems strange to use a hard-to-find AC power source rather than a commonly available DC wall ada...

My latest project is a battery management system (BMS) that can accurately measure cells in a lithium battery pack, and also perform shunt...

My latest project is a battery management system (BMS) that can accurately measure cells in a lithium battery pack, and also perform shunt balancing and possibly charge shuttling to balance the pack. I would also like to be able to use it for a pack of four 12V SLA batteries. A DG408 could be used to select up to 8 cell voltage taps from nominal 3.2V (LiFePO4) or 3.7V (Li-Ion), with a ma...

Disclaimer: I'm not looking for the best drone power supply. I enjoy using high quality branded products. Of course it's all made in China....

Disclaimer: I'm not looking for the best drone power supply. I enjoy using high quality branded products. Of course it's all made in China. That is IMO a good reason to pay close attention to branding. I intend to pay VERY close attention to my battery pack temperature, and to take the endeavor very slowly. I have a spare Dewalt 20 V Max 6 amp hour battery, and a load of new 18650 bat...

OT: Solar Charging 12V Car Battery... My son, Aaron, software engineer turned farmer, has acreage in the San Tan Valley with no source of...

OT: Solar Charging 12V Car Battery... My son, Aaron, software engineer turned farmer, has acreage in the San Tan Valley with no source of electric power. He'd like some artificial light for his chicken coop to increase the egg output. Lighting and timers are easy to find off-the-shelf, but I need some pointers toward finding a good quality solar panel that can charge a 12V car batter...

I have a battery charger that is rated at 2, 15, or 100 amps. It's a Everstart WM-1510 ma model. (Walmart). I found that Schumacher has...

I have a battery charger that is rated at 2, 15, or 100 amps. It's a Everstart WM-1510 ma model. (Walmart). I found that Schumacher has an identical charger model SE-1510 ma. That says these Everstart chargers are made by Schumacher. Anyhow, the 12v circuit breaker has died and will not reset. That seems to be the most common problem on all chargers. My question is this. The Schu...

Marco Reps has an interesting article on low noise amplifiers: Ultralow Noise Tester: 9V Battery vs. 7805 vs....

Marco Reps has an interesting article on low noise amplifiers: Ultralow Noise Tester: 9V Battery vs. 7805 vs. LTZ1000 https://www.youtube.com/watch?v=XpbDMo8an5w - uses ADA4523: $3.030 Mouser, Digikey, 4.2 nV/sqrt(Hz), RRIO, 100pA Ib - Datasheet https://octopart.com/search?q=ada4523 Cross-correlation would improve noise floor. Hard to get down to Gerhard's level, but maybe doable. ...

Could some electronics guru please shed some light on this ? Several Web sites(please check list below) have schematics and flashy color...

Could some electronics guru please shed some light on this ? Several Web sites(please check list below) have schematics and flashy color photographs of single white led light powered off a single 1.5 Volt AA battery. http://cappels.org/dproj/ledpage/leddrv.htm http://www.electroschematics.com/6195/high-efficiency-led-with-1-5-volts/ dinspirations.com/appliedcontent/Projects/Proj-WhiteLED...

I am wiring up 4 banks of batteries with dip40 pin & zif. Considering 4 battery banks: Min 360V, Max 400V _A_ _B_ _C_ _D_ 370 380 390...

I am wiring up 4 banks of batteries with dip40 pin & zif. Considering 4 battery banks: Min 360V, Max 400V _A_ _B_ _C_ _D_ 370 380 390 400 400 390 380 370 connected with X ohm at Y duty 1. what Z AWG do i need? X Y Z 1 10 5 25 10 50 ohm % AWG 2. What is the equiv. W AWG for pin headers and 3M zif sockets Z should be < W Y can be lower

Just stick a needle in it to release the pressure. There are more than a few such videos on YouTube.

Just stick a needle in it to release the pressure. There are more than a few such videos on YouTube.

This is way worse than any electric car situation could ever be...

This is way worse than any electric car situation could ever be...

What do you folks think about this gem: https://www.youtube.com/watch?v=cpaWCedoptA I like the special high reluctance transformer and...

What do you folks think about this gem: https://www.youtube.com/watch?v=cpaWCedoptA I like the special high reluctance transformer and kindling used as insulation.

https://wattsupwiththat.com/2022/02/18/was-the-felicity-ace-fire-caused-by-electric-vehicle-batt eries/ -- I yam what I yam - Popeye

https://wattsupwiththat.com/2022/02/18/was-the-felicity-ace-fire-caused-by-electric-vehicle-batt eries/ -- I yam what I yam - Popeye

Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell....

Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell.