dead unused NiMH AA cells

Started by Adam Funk in sci.electronics.basics5 years ago 6 replies

I recently opened a pack of NiMH AAs that I'd had lying around for a while, & some of them wouldn't charge at all. I tried putting them in the...

I recently opened a pack of NiMH AAs that I'd had lying around for a while, & some of them wouldn't charge at all. I tried putting them in the fancy German charger as well (I can't remember the model name, but it's the one that has discharge, test, & refresh modes) but it just showed "null" for them, as if they weren't even there. Is there some need to charge NiMH cells as soon as you buy ...


NiMH batteries

Started by AK in sci.electronics.basics10 months ago 2 replies

I bought some EBL aaa nimh batteries. Voltage is 1.3 v. Does that mean they are already fully charged? Andy

I bought some EBL aaa nimh batteries. Voltage is 1.3 v. Does that mean they are already fully charged? Andy


Charging NiMh batteries when not completely discharged

Started by AK in sci.electronics.basics7 months ago 26 replies

The aaa alkaline batteries went out on my tv remote. I decided to use my NiMh UBL aaa batteries. 1100 mAh. They are currently showing 1.31...

The aaa alkaline batteries went out on my tv remote. I decided to use my NiMh UBL aaa batteries. 1100 mAh. They are currently showing 1.31 volts. And they work ok in the remote as is. My charger is the manual type. It charges that type at 150 mA. I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline. I would like to know how much longer to charge them...


Replacement NiMh battery for small solar light

Started by AK in sci.electronics.basics6 months ago 1 reply

I replaced a 600 Mah NiMh battery in a small solar light with a 2300 Mah since I had no 600 Mah hr batteries in my stock. It worked great for...

I replaced a 600 Mah NiMh battery in a small solar light with a 2300 Mah since I had no 600 Mah hr batteries in my stock. It worked great for about a week, but then the light started blinking when it should be on steadily. Is it because the solar panel can not charge a battery with 4 times the capacity? Andy


Reviving 'dead' PP3 NiMH?

Started by Terry Pinnell in sci.electronics.basics4 years ago 6 replies

Some of my PP3s steadfastly refuse to recharge. Neither in my 'intelligent' nor basic chargers. Despite being years old, I'm reluctant to dump...

Some of my PP3s steadfastly refuse to recharge. Neither in my 'intelligent' nor basic chargers. Despite being years old, I'm reluctant to dump them. Any tips from others who have managed to bring these back into service please? -- Terry, East Grinstead, UK


Wanted: A 'joule thief' style circuit design...

Started by ~misfit~ in sci.electronics.basics4 months ago 15 replies

... that I can use to drain alkaline cells and push the 'charge' into either a lithium-Ion cell (for a flashlight), a phone or a powerbank. I...

... that I can use to drain alkaline cells and push the 'charge' into either a lithium-Ion cell (for a flashlight), a phone or a powerbank. I have a combined wireless doorbell - inside/outside thermometer that I quite like. Unfortunately it won't run on NiMH cells and only uses alkalines down to 1.33v. (It's the only thing I have that doesn't run on rechargeable cells.) The sender uses...


NiMH charger recommendations?

Started by DaveC in sci.electronics.basics8 years ago 20 replies

First of all, this is a request for a *recommendation*, not a request for someone to do Google searches for me. - - - I need a charger for AA,...

First of all, this is a request for a *recommendation*, not a request for someone to do Google searches for me. - - - I need a charger for AA, AAA, and 9v batteries. Four of the AA or AAA at a time is OK. I see very few that support all these batteries (Maha makes a separate charger for 9v). Of those that do, not all use delta-V termination (or don't specify). Of those remaining th...


Soldering onto NiMH batteries?

Started by DeanB in sci.electronics.basics12 years ago 9 replies

Hello all, I've only done a little soldering before, but I want to rebuild a battery pack for my TI-59 calculator (which is basically 3...

Hello all, I've only done a little soldering before, but I want to rebuild a battery pack for my TI-59 calculator (which is basically 3 AA-sized batteries soldered together in series). Can I just solder directly onto the battery terminals? With a copper wire. Should I use flux? Will this overheat the battery and/or blow it up? Thanks for any tips!


lm555 timer problem

Started by Cliff Hartle in sci.electronics.basics9 years ago 18 replies

I have a basic off the shelf astable timer circuit with the diode for less than 50% duty cycle thats on this...

I have a basic off the shelf astable timer circuit with the diode for less than 50% duty cycle thats on this page. http://www.doctronics.co.uk/555.htm#more_astables I hooked it up with 4 AAA NiMH batteries. I used an LED to get the resistors correct for the timing I need and it all works. I'm going to drive a relay with this circut so I hooked up a 5v reed relay with a protection d...


OT: cordless screwdriver

Started by Pimpom in sci.electronics.basics7 years ago 15 replies

Is anyone familiar with the cordless screwdriver in the link or a similar one? I'd like to know if using rechargeable 1.2V NiCd or NiMH cells...

Is anyone familiar with the cordless screwdriver in the link or a similar one? I'd like to know if using rechargeable 1.2V NiCd or NiMH cells instead of the specified 1.5V alkalines will result in a severely reduced torque. http://www.ebay.com/itm/Black-Decker-6-Volt-Alkaline-4-AA-Battery-Operated-Cordless-SCREWDRIVER- NEW-/251240800353?pt=Power_Tools&hash=item3a7f1e6061


OT Lipo battery charger

Started by George Herold in sci.electronics.basics4 years ago 1 reply

So my son is into RC... He's bought some old RC cars back to life and watns to run them with new Lipo batteries. We are now looking for a...

So my son is into RC... He's bought some old RC cars back to life and watns to run them with new Lipo batteries. We are now looking for a battery charger. Any recommendations? price ~$100. This one in particular, http://www.ebay.com/itm/Venom-Pro-Duo-80W-X2-Dual-AC-DC-7A-LiPo-NiMH-RC-Battery-Balance-Charger- /401004922785 TIA George H.


Trickle charge C-type NiMh?

Started by Terry Pinnell in sci.electronics.basics2 years ago 6 replies

I have some inexpensive 220 mAH C-type Ni-Mh batteries, https://www.amazon.co.uk/gp/product/B07BJ85NNZ The equivalent 3300 mAh C-Types I bought...

I have some inexpensive 220 mAH C-type Ni-Mh batteries, https://www.amazon.co.uk/gp/product/B07BJ85NNZ The equivalent 3300 mAh C-Types I bought a couple of years ago specified charging with 330 mA for 16 hours, but these new ones have no charging data. I have three soldered together and obviously charge in series. I've been using a trickle charge of 25 mA in the circuit of my curtain contr...


=?ISO-8859-1?Q?Rechargeable=A0Batteries?=

Started by alice in sci.electronics.basics7 years ago

Hi all, Rechargeable Batteries: High capacity rechargeable NiMH batteries for digital cameras that use AA, AAA batteries, handheld radios at...

Hi all, Rechargeable Batteries: High capacity rechargeable NiMH batteries for digital cameras that use AA, AAA batteries, handheld radios at long life. Shop online huge selection of rechargeable batteries. If you are looking for batteries and other related items then visit: http://www.greenbatteries.com/rechargeable-batteries.html for more details.


Overcharging NiMh batteries?

Started by Bill Bowden in sci.electronics.basics4 years ago 3 replies

My neighbor has a solar powered outdoor decoration light that cycles through several colors but only runs for maybe an hour at night. It has a...

My neighbor has a solar powered outdoor decoration light that cycles through several colors but only runs for maybe an hour at night. It has a single 1200 mAh 1.2 volt rechargeable battery and a couple small solar cells to charge the battery. I measured the load current at 15 milliamps and the charge current at only 1.3 milliamps so it appears the solar array is not charging the battery ...