Are people still designing new products with NiMH batteries? - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: July 14, 2023, 09:07:39 am
content: Or to put it another way, do you think the NiMH battery is going to go extinct within a few years?Just curios to see where the market is going.Eneloop fixed the NiMH self discharge problem but presumably this is still covered by a patent so there are no clones that I'm aware of.

author: Haenk
author_rank: Super Contributor
timestamp: July 14, 2023, 09:14:53 am
content: Quote from: e100 on July 14, 2023, 09:07:39 amThere are a couple are brands available, for many years now. And those are not rebranded Eneloops. Still is possible, they have to pay license fees to Panasonic, I don't know.IMHO the NiMH are still good for plenty of years, as they are a consumer-friendly replacement for Alkaline batteries. Of course Lithium-based cells have many benefits, but the ease of use is simply not there (yet).

author: Miyuki
author_rank: Frequent Contributor
timestamp: July 14, 2023, 10:08:54 am
content: They will be with us for many yearsNow they have only little benefits over Lithium based ones, basically, only safety is better and some can tolerate higher temperatures, but all other parameters are better in Lithium ones, even the price.But consumer AA and AAA cells are really useful stuff.

author: alm
author_rank: Super Contributor
timestamp: July 14, 2023, 10:51:13 am
content: Shipping lithium batteries is more complicated. I expect cheap devices like fly swatters to keep shipping with alkaline batteries, or without batteries, so then NiMH is an easy upgrade for consumers.In addition there's quite a large number of existing portable devices that use AA/AAA/9V batteries like clocks, remotes and multi-meters.

author: wasedadoc
author_rank: Super Contributor
timestamp: July 14, 2023, 11:07:14 am
content: NiMH cells come in standard sizes which are readily available and can be fitted by the end-user. Devices using Li cells are effectively throw-away items for the vast majority of end users.

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 14, 2023, 01:18:09 pm
content: There are lithium batteries with buck regulators to make them drop in replacements for standard AAs. Not sure if they'll replace NiMH completely.

author: Infraviolet
author_rank: Super Contributor
timestamp: July 14, 2023, 02:25:43 pm
content: When you can get away with their limitations (worse energy to weight ratio, slower charging cycle...) NiMH makes sense in many designs. Unlike Li cells there's no chance of them spontaneously combusting, and they don't need special treatment in terms of protection circuitry around them, and coming in standard AA/AAA/... form factors means you aren't dependent on one supplier of one specific sized pouch cell which matches your mechanical design, you can get any brand of NIMH cells of the right sort of range of mAh capacity.To be honest, its only really things which self-propel (drones, RC cars...) and things which need to supply very high peak currents (cordless power tools) where LiPo's have an absolute advantage, for other things NiMH's disadvantages can be pretty tolerable.

author: ajb
author_rank: Super Contributor
timestamp: July 14, 2023, 03:16:27 pm
content: We still have and regularly use multiple sets of AA and AAA NiMH batteries around the house. Plenty of devices around that still take those battery formats, and not a big deal to swap them out when needed. The ones that Ikea sells (and their chargers) are decent and well priced compared to major brands.I did recently buy a couple of those AA batteries with the internal lithium cell/DC-DC converter/USB charge port for a device that wasn't working well with the reduced NiHM voltage. Those work fine, too, but are much more expensive than the NiMH cells, and aren't really any more convenient IMO. So I'll keep using the NiMH cells as long as I have things that will take them.

author: Infraviolet
author_rank: Super Contributor
timestamp: July 14, 2023, 03:32:55 pm
content: "port for a device that wasn't working well with the reduced NiHM voltage"Must be a pretty teribly designed device, if it can't work at the 1.2V an NiMH gives for most of its discharge cycle except when very nearly empty, then it will only work for a short fraction of the early part of the lifespan of an alkaline which starts at 1.5V and drops quickly.

author: e100
author_rank: Frequent Contributor
timestamp: July 14, 2023, 04:28:14 pm
content: That under voltage problem brings back memories of the portable Energizer phone charger which was designed to only run from two AA lithium primary cells. If you used regular AA batteries it didn't work. This thing predated the lithium power banks with their fancy USB outputs.https://de2wfhoo6xqi5.cloudfront.net/size/600/0c3/cdf/2913cb2c44cc37b0c41ca61637095de4ac.jpg

author: e100
author_rank: Frequent Contributor
timestamp: July 14, 2023, 04:49:50 pm
content: That Ikea mention sent me down a rabbit hole that gave this page about rebranded Eneloops.https://eneloop101.com/batteries/rewrapped-batteries/Seems that things are quite complicated with different generations and manufacturing shifting between Japan and China.

author: coppice
author_rank: Super Contributor
timestamp: July 14, 2023, 05:00:57 pm
content: Quote from: e100 on July 14, 2023, 09:07:39 amI doubt the AAA and AA types will go away any time soon. You can't really use lithium types as a substitute. Some of the embedded uses of NiMH seem to be shrinking, like toothbrushes. Now they can run those on a single NiMH cell, with a 0.9V MCU, I'm not clear why lithium offers them an advantage. Perhaps they just want to sound cool and modern for anything but the most basic models.Quote from: e100 on July 14, 2023, 09:07:39 amEneloops are pretty old now. Surely any patents have expired.

author: ajb
author_rank: Super Contributor
timestamp: July 14, 2023, 05:52:24 pm
content: Quote from: Infraviolet on July 14, 2023, 03:32:55 pmWell, it's a motorized cat toy that cost like $10, so I won't try to argue with thatIt takes three cells and was just a little sluggish right out of the gate with freshly charged NiMH versus fresh alkalines. And yes, if you replaced the alkalines when it got similarly sluggish you'd be throwing away a good bit of their capacity. The USB-rechargeable replacements are supposed to maintain close to 1.5V until they drop out completely, so in theory should perform much better in general. They seem to be working well so far. My only gripe so far is that I specifically chose ones with USB C charge connectors, but they don't have CC pulldown resistors and so don't work with USB C PD chargers. I guess they expect you to only use the included A to 4xC squid cable.