9V PS

Started by OldGuy in sci.electronics.design4 years ago 17 replies

Looking for the simplest way to this. AC powered 9V wall-wart or 9V battery powering a circuit. 9V battery is alkaline so is not charged by 9V...

Looking for the simplest way to this. AC powered 9V wall-wart or 9V battery powering a circuit. 9V battery is alkaline so is not charged by 9V AC supply. Load is < 50 ma. When AC is on, power from the AC to 9v PS. AC off, power from 9V battery. 9V battery only supplies power when 9V AC is off. The catch: the 9V AC PS output may be lower than the 9V battery or visa versa. So a si


Car battery matching with alternator

Started by cameo in sci.electronics.design3 years ago 44 replies

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...


OT Car Battery Explodes

Started by Gerhard in sci.electronics.design7 years ago 70 replies

Yesterday my wife's Toyota Corolla had a battery moment. When she started the car, after it had been parked it for about two hours, there was...

Yesterday my wife's Toyota Corolla had a battery moment. When she started the car, after it had been parked it for about two hours, there was a loud explosion. The results of the battery's side splitting event can be viewed at ftp://ftp.meraka.csir.co.za/pub/in/Battery_Explode/ The battery centre suggested it was possibly over charged. After I installed the new battery I measured a...


Li Battery

Started by OldGuy in sci.electronics.design2 years ago 18 replies

I got a replacement battery for my laptop. It is a Li-Ion type. 6 cell 4400 mAh 10.8 volt In the package docs it states that I should cycle...

I got a replacement battery for my laptop. It is a Li-Ion type. 6 cell 4400 mAh 10.8 volt In the package docs it states that I should cycle the battery all the way down, recharge it and do this several times to improve its capability. What is happening to the battery doing this? If not done what can I expect in terms of the amount of loss of use? --- news://freenews.netfront....


Is there an app which will stress TEST a cellphone battery?

Started by Ahmed E. Souaiaia in sci.electronics.design4 years ago 50 replies

Is there freeware which will expressly stress test a cellphone battery? There are plenty of battery saver Android apps (e.g., Battery Doctor);...

Is there freeware which will expressly stress test a cellphone battery? There are plenty of battery saver Android apps (e.g., Battery Doctor); but, is there a specific Android battery stress-test application? My Samsung Galaxy SIII will last only about two hours with anything useful running (e.g., GPS) and, with the battery hogs turned off (mostly GPS but WiFi, Bluetooth, etc., are inclu...


1M ohm resistor across battery terminals - Why?

Started by Chappy in sci.electronics.design7 years ago 24 replies

I have a pocket laser power meter which recently stopped...

I have a pocket laser power meter which recently stopped working. http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productid=1403 After disassembling it I discovered that the (non-removable) battery is flat (3.5V battery now pushing only 1.5V). The battery had a 1 M ohm resistor soldered across the terminals. It is a 750maH 3.5V lithium thionyl chloride battery (LTC-7PN). ...


Can powerbanks shorten lithium battery life ?

Started by Andy K in sci.electronics.design1 year ago 36 replies

I have a powerbank that I use to charge my cell phone. 10,400 ma is it's capacity. Output 3.7 V It has 2 outputs. 1.0 and 2.1 amps and...

I have a powerbank that I use to charge my cell phone. 10,400 ma is it's capacity. Output 3.7 V It has 2 outputs. 1.0 and 2.1 amps and I use the 2.1 amp My cell battery is about one yr old. (Replacement for orig battery) After charging the battery, it only lasts about 2 days before going dead. During those 2 days, there was no cell phone usage. Battery capacity is listed as...


Lithium Ion Battery and RoHs

Started by Anonymous in sci.electronics.design4 years ago 3 replies

Hi, I am considering using the following battery http://ultralifecorporation.com/be-commercial/products/rechargeable/ubp001/ Its...

Hi, I am considering using the following battery http://ultralifecorporation.com/be-commercial/products/rechargeable/ubp001/ Its not RoHs approved. I heard that Europe does not accept electronics devices if they are not RoHs approved. Does LiIon battery need to be RoHs approved? This battery is UL approved and the company says that they sell this battery in europe. jess


Battery Charger Design

Started by thorin92 in sci.electronics.design8 years ago 28 replies

Dear group, I am trying to design a battery charger for this...

Dear group, I am trying to design a battery charger for this battery: http://uk.farnell.com/varta/55615605940/battery-pcb-mount-6v-5-v150h/dp/863981 I'm familiar with voltage regulators and current limiting etc. but am unsure what parameters to use? If I simply provide 6v limited to 70mA will this work? Thanks in advance


Update on 787 Battery Problems

Started by Joe Gwinn in sci.electronics.design5 years ago 65 replies

I just read the 18 March 2013 issue of Aviation Week. On pages 28-29, there are two articles on the 787 battery investigation results...

I just read the 18 March 2013 issue of Aviation Week. On pages 28-29, there are two articles on the 787 battery investigation results and proposed fixes. What caught my eye, and apparently that of the investigators, was that there was never an all-up test of the 787 battery charging system with the actual Yuasa-made production battery. They were tested independently, but there is no re...


Lead acid battery desulfination?

Started by Jan Panteltje in sci.electronics.design3 years ago 57 replies

Been trying to 'desulfinate' a 13Ah lead acid battery now for a few weeks. The method I used is to run 200 mA at 16V into a 12V battery. The...

Been trying to 'desulfinate' a 13Ah lead acid battery now for a few weeks. The method I used is to run 200 mA at 16V into a 12V battery. The battery had only 1/10 of capacity, now it has 1/8. Takes too long for my liking, would several month that way. So did some googling, and found this circuit diagram only: http://images.yuku.com.s3.amazonaws.com/image/pjpeg/f1116c552716baf0a54f0050308e...


9V Battery or 2 x AAA with 9V Converter

Started by Anonymous in sci.electronics.design4 years ago 34 replies

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...


Can car batteries work upside-down?

Started by Dave Vanden Bout in sci.electronics.design9 years ago 27 replies

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...


Synchronous rectifier - gotcha

Started by Raveninghorde in sci.electronics.design7 years ago 23 replies

I'm using the LM3150, synchronous buck regulator, in a number of designs. Now it is sorted it works well. Just been using it on a battery...

I'm using the LM3150, synchronous buck regulator, in a number of designs. Now it is sorted it works well. Just been using it on a battery charger and at end of charge I set the voltage to zero. Gotcha. The bottom FET is left turned on and the fuse blows because it shorts out the battery. I use FETs to protect against a reversed battery and to stop the battery discharging into the electr...


Li-Ion battery model

Started by Yzordderrex in sci.electronics.design6 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


Design Battery Charger using H-bridge Mosfet concept

Started by samson.bunty1986 in sci.electronics.design5 years ago 10 replies

Hi, Am planing to design a battery charger using H bridge mosfet configuration . Battery spec as follows: Battery voltage ---24V Battery...

Hi, Am planing to design a battery charger using H bridge mosfet configuration . Battery spec as follows: Battery voltage ---24V Battery capacity -- 45Ah So the charging current should be 10% of battery capacity. am i correct?? So the charging current is 5A. Am having some querys. What are the mosfets hve to be used?? Is it 2 N-channel & 2 P channel mosfets?? How to controll th...


Asus Eee drains battery while "off"

Started by Anonymous in sci.electronics.design9 years ago 18 replies

"Power supply drains when eee 900 switched off?" http://forum.eeeuser.com/viewtopic.php?id=34479 The battery seems to be at ~7.98 V and the...

"Power supply drains when eee 900 switched off?" http://forum.eeeuser.com/viewtopic.php?id=34479 The battery seems to be at ~7.98 V and the leakage current is 14 mA. Which leaves the computer bootable for a maximum of 9 days after last charge. Battery controller is MAX8724. Any idea (educated guess) what might be draining the battery ..? There's quite a few people that bought these ;)


Charger for SLA 12V / 7Ah battery

Started by gm in sci.electronics.design2 years ago 32 replies

The subject says all :-) I connected 3 x 12V / 7Ah battery's is serial and start to charge them with my ebike 36V/1,2A charger. After cca 30...

The subject says all :-) I connected 3 x 12V / 7Ah battery's is serial and start to charge them with my ebike 36V/1,2A charger. After cca 30 minutes battery pack was getting hot, so i disconnect the whole stuff. What is the highest charging current for such battery's ? The funny thing is that i use the same charger to recharge my 36V ebike battery pack, and there was no problems whats...


solar panel on sealed lead acid battery

Started by Fibo in sci.electronics.design3 years ago 19 replies

Hello, I was wondering if anyone had any experience with using a solar power "maintainer" on a sealed lead acid battery? I have this...

Hello, I was wondering if anyone had any experience with using a solar power "maintainer" on a sealed lead acid battery? I have this battery http://expertpower.hostedbywebstore.com/12v-7Ah-SLA-Rechargeable-Battery/dp/B003S1RQ2S and was thinking about buying this Solar Battery Maintainer to keep it charged http://www.sunforceproducts.com/product_details.php?PRODUCT_ID=248 the batt...


LiIon Battery Question

Started by Jim Thompson in sci.electronics.design11 months ago 33 replies

LiIon Battery Question... Is there a voltage below which the battery is considered toast, or is a battery that is totally discharged...

LiIon Battery Question... Is there a voltage below which the battery is considered toast, or is a battery that is totally discharged rechargeable? ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Syst...