Charge AAAs without removing from device??

[Blu3R]

Hi all,
Is it possible to recharge AAA batteries without actually removing them from the device they’re powering?
I’ve got a home thermostat that kills its batteries within a year. Every time I change them I have to then reprogram all the settings which is an unnecessary chore.
If I could somehow charge these batteries without removing them I’d not have to go through the tedious reprogram every year.

[The_Jackal]

Only if the device has a charging circuit built into it.
A lot of RC Transmitter have this functionality.
Is there no internal battery that may be flat and is not retaining the settings?
Do the manufacturers have a solution, as it sounds very annoying and all customers would have that problem.

[untakenname]

You can get lithium AAA batteries which have triple the energy density of normal Alkaline cells.

[Ham_and_Jam]

Which thermostat is it?

[Blu3R]

It’s a LightwaveRF stat. Definitely not something I’d recommend but I’m invested in their kit now so have to make the most of what it offers.

There’s no battery backup for this, it’s a real pain.

[The_Jackal]

Hardwire it?

[Ham_and_Jam]

Blu3R said:

It’s a LightwaveRF stat. Definitely not something I’d recommend but I’m invested in their kit now so have to make the most of what it offers.

There’s no battery backup for this, it’s a real pain.

I’ve got a few bits of lightwaveRF stuff. Mainly lighting as there switches are quite good.

However I needed a bit more than they do so I integrated it all into Vera home automation (Z-Wave). Now the lightwave lights are all activated from Vera using a 433mhz antenna.

Might be a good way for you to go if you need to expand / move to a better system.

Short term, can’t you save your thermostat schedule to the lightwave app?

[nyt]

This is a really long shot but perhaps something like https://www.aliexpress.com/item/4001290311186.html... might do the trick

It's not clear whether they can provide power at the same time as they charge.

Other makes exist which may be better or more reputable.

ETA link to AAA battery: https://www.aliexpress.com/item/4001292894307.html...

https://www.aliexpress.com/item/33025574301.html

Edited by nyt on Wednesday 2nd September 12:48

[SpamDisco]

Xbox controllers can charge and play at the same time from a usb cable, these packs contain 2 X AAA rechargeable batteries.

https://www.microsoft.com/en-gb/p/venom-xbox-one-t...

Possibly could be adapted for you to use?

[Ham_and_Jam]

These might do the trick. Look like they should work.

AAA Batteries,Rechargeable AAA Batteries 450mAhwith USB Ports - High-Capacity Batteries Long-Lasting Power Recyclable Recharge Battery by USB Cable-（4 Count） (4AAA) https://www.amazon.co.uk/dp/B07RTK5QJG/ref=cm_sw_r...

[Blu3R]

Thank you all for the suggestions.

The_Jackal said:

Hardwire it?

I did consider this as the original stat has a mains cable still buried in the wall. I could attach a small DC supply to the other end in the boiler cupboard and provide the power, but it's a bit of a faff.

Ham_and_Jam said:

Blu3R said:

It’s a LightwaveRF stat. Definitely not something I’d recommend but I’m invested in their kit now so have to make the most of what it offers.

There’s no battery backup for this, it’s a real pain.

I’ve got a few bits of lightwaveRF stuff. Mainly lighting as there switches are quite good.

However I needed a bit more than they do so I integrated it all into Vera home automation (Z-Wave). Now the lightwave lights are all activated from Vera using a 433mhz antenna.

Might be a good way for you to go if you need to expand / move to a better system.

Short term, can’t you save your thermostat schedule to the lightwave app?

Sounds a bit too techy for me, I'm not likely to be able to get that to work without many headaches that I just don't fancy giving myself.
Adding the schedule to the app is fine when the app works, but inevitably it doesn't when you really need it.


I'll buy some of those USB batteries and give them a go. Just need to check that they can be charged in situ without switching off the device!

[rxe]

untakenname said:

You can get lithium AAA batteries which have triple the energy density of normal Alkaline cells.

.... and decent Alkalines have double the capacity of a typical rechargeable.

Lithium primary cells are really good for long term low drain stuff. (e.g. stick them in the TV remote, likely to outlast the TV)