Charge gel cell with car charger?

Started by Mike Cook in sci.electronics.design9 years ago 89 replies

A friend has a battery powered Ryobi lawn trimmer ("weed whacker") which doesn't work. The 12vdc wall wart puts out only ~ 12.4v. I charged...

A friend has a battery powered Ryobi lawn trimmer ("weed whacker") which doesn't work. The 12vdc wall wart puts out only ~ 12.4v. I charged the lead-acid gel cell using a car charger. The charge rate (selectable) was 0.5A. Afterward the trimmer seemed to work as new. Can the car charger be used to charge this battery? He can install a timer to limit charge time if that's something req...


LiPo charging

Started by Andy in sci.electronics.design4 years ago 9 replies

Can I use the same charger I use for my 18650 batteries with a LiPo battery? LiPo battery is 500 mah. Charger puts out 450 ma. Thanks.

Can I use the same charger I use for my 18650 batteries with a LiPo battery? LiPo battery is 500 mah. Charger puts out 450 ma. Thanks.


Good Emergency Phone Charger

Started by David Eather in sci.electronics.design10 years ago 8 replies

I've been looking for one of these that is worth having. I tried plenty of lithium emergency battery charger packs. Most had appalling...

I've been looking for one of these that is worth having. I tried plenty of lithium emergency battery charger packs. Most had appalling efficiency or were badly made or had batteries so bloated from overcharging the product couldn't be re-assembled after a visual inspection. Some had all the faults combined. I looked at single cell AA - 5 volt chargers and again it was mixed. Some were...


Power tool battery charge

Started by Sylvia Else in sci.electronics.design3 years ago 9 replies

This charger claimed that both my batteries are faulty, which seemed a but of a coincidence, so I suspected the charger instead. Here's a...

This charger claimed that both my batteries are faulty, which seemed a but of a coincidence, so I suspected the charger instead. Here's a picture of the board: https://www.dropbox.com/s/saeqrsralcdsc54/chargeBoard.jpg?dl=0 I'm puzzled by the largish round holes, both in the middle of the board, and diagonally towards the left, in the proximity of the labels for C13 and R43. In both ...


SLB and charger question

Started by Andy K in sci.electronics.design8 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.


Somewhat over-engineered for a lipo charger?

Started by Cursitor Doom in sci.electronics.design6 years ago 13 replies

I think the guy who designed this single cell charger for LiPo batteries must have been paid by number of components used. I've no idea what...

I think the guy who designed this single cell charger for LiPo batteries must have been paid by number of components used. I've no idea what half of this stuff is supposed to do. This model was produced in 2002 for a couple of years. What d'yall make of it? Only the first 3 pictures in this folder, guys. The rest of the pictures are of something else entirely out of a scope, so just i...


OT: Lead Acid Float Charger

Started by Jim Thompson in sci.electronics.design5 years ago 79 replies

I drive my pick-em-up truck every few months. So the battery is dead when I go to use it... like today :-( I'm looking for recommendations...

I drive my pick-em-up truck every few months. So the battery is dead when I go to use it... like today :-( I'm looking for recommendations for the _best_ (*) float charger I can buy to just plug the truck into when it's parked. (*) Cost no object. ...Jim Thompson -- | James E.Thompson | mens | | Analo...


Battery charger with solar panel

Started by gm in sci.electronics.design5 years ago 20 replies

Hi to all. Did someone try this approach: http://cds.linear.com/image/314_circuit_1.jpg when designing solar charger ? Power consumption...

Hi to all. Did someone try this approach: http://cds.linear.com/image/314_circuit_1.jpg when designing solar charger ? Power consumption will be under 75Wh per day.. Other infos: - solar panel 15W - battery 12V / 7Ah GM


NiMh charging formula

Started by Andy K in sci.electronics.design7 years ago 22 replies

I have a "dumb" NiMh/NiCd charger. For 9 volt batteries, it specifies 25 milliamps. The charger manual gives this charge...

I have a "dumb" NiMh/NiCd charger. For 9 volt batteries, it specifies 25 milliamps. The charger manual gives this charge formula. Charging time(h) = 1.2 x battery capacity (mAh) -------------------- charging current (mA) 13.44 hrs. Is is formula useful or is there something better that factors in the starting Voltage ? Thanks.


dodgy lead acid battery

Started by Anonymous in sci.electronics.design4 years ago 2 replies

Have one of those 12v jump starter light compressor things, don't know where it came from. The allegedly 17Ah battery in it showed no output, so...

Have one of those 12v jump starter light compressor things, don't know where it came from. The allegedly 17Ah battery in it showed no output, so hooked it up to an old dumb unregulated charger & left it, walking by it now & then. Charger put out about 15v. It began to take a tiny trickle of charge, hardly any. Then to my surprise I saw it sucking up 3A of charge! What's more it appe


Li-Ion battery model

Started by Yzordderrex in sci.electronics.design10 years ago 8 replies

Greetings. I am involved with a Lithium Ion Phosphate battery charger design. I am trying to get a handle on the behavior of the battery in...

Greetings. I am involved with a Lithium Ion Phosphate battery charger design. I am trying to get a handle on the behavior of the battery in order to figure out how to get it to play nice with the charger. I think the battery is going to act like a big capacitor. It has a 0.25v drop after about 2 amp*hours, and a internal impedance of


Shady Dell laptop practices

Started by bitrex in sci.electronics.design4 years ago 41 replies

On some of the inexpensive Dell laptops they implement a hardware-lockout system intended to prevent you from using aftermarket charger bricks...

On some of the inexpensive Dell laptops they implement a hardware-lockout system intended to prevent you from using aftermarket charger bricks to charge the battery. The way they do this is there's a chip in the Dell charger that contains a unique identifier which a chip on the laptop mobo requests from it on startup over a one-wire interface. If on boot the BIOS can't confirm that the ...


LiPo charger question

Started by bitrex in sci.electronics.design5 years ago 3 replies

I have a little LiPo charger module, this one: https://www.adafruit.com/product/1304 It's based on the following...

I have a little LiPo charger module, this one: https://www.adafruit.com/product/1304 It's based on the following IC: https://cdn-shop.adafruit.com/datasheets/MCP73831.pdf There doesn't seem to be any breakout on the dev board provided to give a "power good" signal to a microprocessor when the battery is finished charging. I'd like the host device to be un-turn-onable while the b...


Charging "tall" battery stacks

Started by Don Y in sci.electronics.design5 years ago 87 replies

I've several 48V, 9AHr battery stacks (4x12V@9AHr) that power a system, here. "In theory", as all of the batteries see the same load, they...

I've several 48V, 9AHr battery stacks (4x12V@9AHr) that power a system, here. "In theory", as all of the batteries see the same load, they should all degrade in lock step. "In practice", you expect some variations. How much can I potentially gain (life, capacity, etc.) if I design a "stacked charger" (e.g., 4 floating 12V chargers) instead of a single 48V charger? At the very least,...


Duracell wireless charger, how does it work?

Started by mike in sci.electronics.design9 years ago 16 replies

I picked up a Duracell wireless charger at a garage sale. Model CP-PPS. Also known as MyGrid. Jentec AH 1815-B Rated 15V at 1A. It's NOT...

I picked up a Duracell wireless charger at a garage sale. Model CP-PPS. Also known as MyGrid. Jentec AH 1815-B Rated 15V at 1A. It's NOT inductive. Has alternating metal stripes that supply power to contacts on the device adapter. I have the adapter for the ipad, but no ipad. Thought I'd reverse engineer it to see if I could do anything useful. It puts out a square wave from 1V ...


Anyone do USB design, with certs?

Started by Tim Wescott in sci.electronics.design8 years ago 14 replies

I have a customer who wants a USB-powered battery charger designed, with certification -n- all. I figure the certification part will be harder...

I have a customer who wants a USB-powered battery charger designed, with certification -n- all. I figure the certification part will be harder than the charger part, so I have to give it a pass. Anyone do that and have spare cycles, or know someone? He wants someone with a track record, or I'd talk him into using me! -- Tim Wescott Wescott Design Services http://www.wescottdesi...


NiCad vs NiMH Charging

Started by Anonymous in sci.electronics.design7 years ago 7 replies

I have several Motorola Talkabout radios. In some of them the NiCad batteries won't take a charge anymore. I see new compatable batteries that...

I have several Motorola Talkabout radios. In some of them the NiCad batteries won't take a charge anymore. I see new compatable batteries that are NiMH. Do they require a different kind of charger? The charging station is basically a AC adaptor going into a plastic base that the radios sit in. Inside the circuitry is just a couple of diodes, some resistors and 2 LEDs. Will i need new charger...


Intel Hex2Bin converter (and DIY 10kW EV battery charger)

Started by P E Schoen in sci.electronics.design6 years ago

I am doing some redesign work on a DIY 10 kW EV battery charger that uses an Arduino as its core processor, and I was able to extract the code...

I am doing some redesign work on a DIY 10 kW EV battery charger that uses an Arduino as its core processor, and I was able to extract the code in Hex format using an AVR Dragon. But I wanted to be able to read the text that is part of the code, used on the display, and I found it very difficult to find an application that does this adequately. I wound up importing the hex file into a Mic...


LT1185-based lead acid battery charger

Started by Piotr Wyderski in sci.electronics.design8 years ago 13 replies

I am designing a prototype charger of a lead-acid battery used as a backup power supply source. The input voltage is synchronously rectified...

I am designing a prototype charger of a lead-acid battery used as a backup power supply source. The input voltage is synchronously rectified 12VAC and the current is


car usb charger not durable

Started by bob in sci.electronics.design8 years ago 28 replies

I have gone through several car usb chargers that plugs into cigarette lighter plug. They usually die in a few months. I just opened one up...

I have gone through several car usb chargers that plugs into cigarette lighter plug. They usually die in a few months. I just opened one up and it has a 34063a IC in it. The circuit is probably similar to this: http://www.ifixit.com/Teardown/Generic+1A+USB+Car+Charger+Teardown/10108 When I plug this in it draws 3mA but the built-in LED doesn't light up. I assume the IC has fried. ...