# Noises coming from a battery charger (or batteries) **URL:** \ **Category:** Factual Questions\ **Created:** [October 8, 2012, 6:00pm UTC](https://boards.straightdope.com/t/noises-coming-from-a-battery-charger-or-batteries/637110 "2012-10-08T18:00:14Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [October 8, 2012, 6:00pm UTC](https://boards.straightdope.com/t/noises-coming-from-a-battery-charger-or-batteries/637110/1 "2012-10-08T18:00:14Z")
We have an Energizer [url=http://data.energizer.com/PDFs/chdc7.pdf] (PDF data sheet). It’s worked problem-free for a few years, and the only batteries we’ve ever put in it are Energizer branded batteries sold with/along side the unit. Recently, we noticed that it will occasionally act a bit contemptuously—it’s started making electronic spitting noises. Not quite an electric crackle, much more as if one of the batteries is off-gassing (maybe it’s not contemptuous as much as flatulent). The noises are short bursts, one or two at a time, then nothing. I don’t know if they repeat, because we’ve unplugged the unit right away. The charger itself is an easy replacement (if that’s where the problem is). If it’s a battery that went bad, is there any way to test which one it is? Any ideas what’s happening? Is it dangerous? Who am I kidding—any plug-in device that begins making unauthorized noises is, generally speaking, a threat to all of humanity. ---
**Author:** ![komolono](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/komolono/32/532_2.png) [@komolono](https://boards.straightdope.com/u/komolono)\ **Post date:** [October 10, 2012, 10:40am UTC](https://boards.straightdope.com/t/noises-coming-from-a-battery-charger-or-batteries/637110/2 "2012-10-10T10:40:36Z")
> [@Rhythmdvl](#): > > a threat to all of humanity. You’ll never know. I ended up destroying my motorhome disregarding the noise coming from it’s battery charger. An exploding capacitor… ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [October 10, 2012, 6:17pm UTC](https://boards.straightdope.com/t/noises-coming-from-a-battery-charger-or-batteries/637110/3 "2012-10-10T18:17:32Z")
I’m inclined to think that you need new batteries if you are still using the original batteries after several years; they don’t last forever, especially if they are frequently used. You should also never mix old and new batteries, rechargeable as well as non-rechargeable (due to capacity differences, rechargeable batteries lose capacity over time; newer batteries often have a higher mAh (capacity) rating as well due to improvements), so they should all be replaced at the same time. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [January 11, 2013, 8:54pm UTC](https://boards.straightdope.com/t/noises-coming-from-a-battery-charger-or-batteries/637110/4 "2013-01-11T20:54:16Z")
Epilogue: Hooray Energizer, way to earn a loyal customer! I eventually contacted them directly, taking a minute to copy the OP into their customer support email. They responded quickly, telling me to ship them the batteries for inspection/replacement per their guarantee (they even included a prepaid mailer). A subsequent email contained the following bit: > [@](#): > > The following tips/information should be helpful: > > A small amount of Hydrogen gas can be emitted from NiMH batteries during charging. However, it is unlikely that this is the source of the odor. It is not unusual for batteries to become warm when charging. The faster the batteries are charged, the hotter the batteries will become. Possibly the odor is coming from the outside of the batteries (something on the label) or maybe the charger itself. Any Energizer rechargeable product that is not performing (i.e. strange odor)can be returned to our customer service department for review. > > We regret any inconvenience this may have caused. We appreciate the input you have provided and will share it with our Quality Assurance. To trouble shoot this issue, we would always recommend cleaning the contacts of the charger with a pencil eraser, as well as the contacts of the batteries. Make sure your charger is unplugged before proceeding. You may also use a cloth to clean the contacts. A lot of times what will happen, is the contacts will build up microscopic debris, causing the charger to misread the battery status. This microscopic debris can simply be left over from manufacturing or just develop over time. If this technique does not stop the blinking light, confirm the batteries are fully installed into the battery bays. Make sure the charger is unplugged when installing the batteries, and if you are only charging two batteries at a time, keep in mind, the batteries must be on the far left or right hand side. Lastly, please make sure you are unplugging the charger after each use. This resets the charger and is a quick fix and saves energy and money. We are confident these tips will help as this is not typical of the batteries to perform this way. We apologize for any inconvenience you may have experienced and appreciate your loyalty to our products. > > Below are the key reasons why lights could be flashing or shows " X ": > > Dirty contacts > Mixing MAH ratings of batteries > Mixing brands > Old batteries (more the 2-3yrs old) > > Please make sure that the charger is plugged directly into the wall outlet not a surge protector, power strip or adaptor with multiple plug-ins. > > Typically NiMH batteries have a normal life of 2 to 5 years. Many factors can impact the life of NiMH batteries. For example, temperature, depth of discharge, charge and discharge current, method of charge control, exposure to overcharge and over discharge, and storage conditions. > > Using the batteries is the best indicator of how they are working. If the NiMH batteries fail to take a charge or do not last as long as they did when originally purchased, they should probably be replaced soon. NiMH batteries will typically lose performance over time (years) and they are not covered under a lifetime guarantee of performance. > > Once again, thank you for bringing this situation to our attention. We hope that you continue to think of Energizer when you purchase lighting products, chargers and batteries.