Hi, just found this site while trying to figure out this issue I'm having, I hope I'm in the right place. I'm not an engineer, just computer enthusiast with a graphic design degree, and now working in IT...so thank you in advance!
So, I have a battery powered lantern, made by Rayovac, that seems to no longer power a light bulb. It uses 4x AA batteries, and a standard little flashlight bulb. Product photo attached below from Google Images.
My daughter has been using it to pretend camp at home for a few years. We're going real camping this weekend, so I grabbed it from her room to put fresh batteries in it, and discovered it doesn't turn on anymore.
I confirmed the new batteries are good, via my multimeter. So I ran to Home Depot last night and got the only flashlight bulb they had: https://www.homedepot.com/p/Nite-Ize-C-D-Cell-LED-Flashlight-Upgrade-Kit-LRB2-07-PR/204787538.
When I installed the bulb, the lantern still didn't not turn on. So I opened up the lantern and grabbed my multimeter.
There's no corrosion at all, looks like it's still new. I tested the voltage before and after the on/off switch, get's 7.06v. I tested right up to the copper contacts / bulb socket, all reading 7.06v. I pulled out the wiring with the copper contacts, and touched the to be bulb to make sure it wasn't a seating issue where the bulb connects, but it still didn't light the bulb. I then installed the bulb into a 2x AA battery flashlight and it turned on just fine. I tested the bulb from the AA flashlight in the lantern, and it didn't power on either. I used the multimeter in place of the bulb to be sure power was getting to the contact, and it read 7.06v. I even measured the voltage right off the bulb's side and bottom, while it was installed in the lantern, to make sure it was getting power. It read 7.06v. I tested the original lantern bulb in the flashlight, it did not work. So I assume it blew.
At this point I took the 4 AA batteries, and taped them together with some wire to make make a circuit, to make sure it wasn't an issue with the bulbs not supporting 7.06v. Both the new bulb and the bulb from the flashlight lit right up. I then put the batteries back into the lantern, and ran wire right from the positive and negative end of the battery chain, and ran them to the bulbs, they lit right up.
At this point I realized I was assuming the 4 batteries together were giving the same 7.06v that I measured inside the lanterns wiring. I decided to confirm this, and measured 6.88v directly from the batteries. I took the batteries out of the lantern, taped all 4 of them together, and measure them, and got 6.88v. I'm not sure if the difference from 7.06v inside the lantern vs the 4 AA batteries' 6.88v is meaningful or not. I looked up the new bulb's specs, it supports 3v-9v. So either way it should work fine. There I'm using is pretty thick (forget what I bought that wire for, maybe something to a computer repair I did). It's nothing crazy though, maybe slightly thicker than traditional car stereo wire. I'm not sure if that affects the voltage not, vs the thinner wire used inside the lantern.
So here's where I'm at:
I have to imagine I'm missing something or misunderstanding something with how the circuit works. I'm not an engineer. I did buy another lantern off Amazon for the camping trip, so I'm mostly just trying to save this from being waste, and am also really wanting to solve this mystery, even it's its for my own future knowledge.
Thank you for coming on this journey with me!
So, I have a battery powered lantern, made by Rayovac, that seems to no longer power a light bulb. It uses 4x AA batteries, and a standard little flashlight bulb. Product photo attached below from Google Images.
My daughter has been using it to pretend camp at home for a few years. We're going real camping this weekend, so I grabbed it from her room to put fresh batteries in it, and discovered it doesn't turn on anymore.
I confirmed the new batteries are good, via my multimeter. So I ran to Home Depot last night and got the only flashlight bulb they had: https://www.homedepot.com/p/Nite-Ize-C-D-Cell-LED-Flashlight-Upgrade-Kit-LRB2-07-PR/204787538.
When I installed the bulb, the lantern still didn't not turn on. So I opened up the lantern and grabbed my multimeter.
There's no corrosion at all, looks like it's still new. I tested the voltage before and after the on/off switch, get's 7.06v. I tested right up to the copper contacts / bulb socket, all reading 7.06v. I pulled out the wiring with the copper contacts, and touched the to be bulb to make sure it wasn't a seating issue where the bulb connects, but it still didn't light the bulb. I then installed the bulb into a 2x AA battery flashlight and it turned on just fine. I tested the bulb from the AA flashlight in the lantern, and it didn't power on either. I used the multimeter in place of the bulb to be sure power was getting to the contact, and it read 7.06v. I even measured the voltage right off the bulb's side and bottom, while it was installed in the lantern, to make sure it was getting power. It read 7.06v. I tested the original lantern bulb in the flashlight, it did not work. So I assume it blew.
At this point I took the 4 AA batteries, and taped them together with some wire to make make a circuit, to make sure it wasn't an issue with the bulbs not supporting 7.06v. Both the new bulb and the bulb from the flashlight lit right up. I then put the batteries back into the lantern, and ran wire right from the positive and negative end of the battery chain, and ran them to the bulbs, they lit right up.
At this point I realized I was assuming the 4 batteries together were giving the same 7.06v that I measured inside the lanterns wiring. I decided to confirm this, and measured 6.88v directly from the batteries. I took the batteries out of the lantern, taped all 4 of them together, and measure them, and got 6.88v. I'm not sure if the difference from 7.06v inside the lantern vs the 4 AA batteries' 6.88v is meaningful or not. I looked up the new bulb's specs, it supports 3v-9v. So either way it should work fine. There I'm using is pretty thick (forget what I bought that wire for, maybe something to a computer repair I did). It's nothing crazy though, maybe slightly thicker than traditional car stereo wire. I'm not sure if that affects the voltage not, vs the thinner wire used inside the lantern.
So here's where I'm at:
- I have a lantern that I can read 7.06v all the way up to the terminals / bulb socket (the on/off switch works just fine too).
- The bulb seems to support the voltage range I'm working with, but there is some variation in voltage when I test the 4xAA batteries directly, vs what I'm reading in the lantern.
- Bulb seems to be making contact with the terminals/socket, and I can read 7.06v off the bulb.
- The batteries work, and the bulb works in a 2xAA flashlight, and when I run wires right from the 4xAA batteries.
- There's no physical damage or corrosion in the lantern.
- The lantern's original bulb does appear to be blown.
I have to imagine I'm missing something or misunderstanding something with how the circuit works. I'm not an engineer. I did buy another lantern off Amazon for the camping trip, so I'm mostly just trying to save this from being waste, and am also really wanting to solve this mystery, even it's its for my own future knowledge.
Thank you for coming on this journey with me!