9 volt rechargable battery reccomendations?

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RunningMan

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#318284 3-Jan-2025 20:51

Anyone here use 9v rechargeables? Just want some for those seldom used appliances and tools that need one and have always gone flat when you need it (looking at you IR thermometer & scales).

Don't currently have a charger, so that would need to be factored in.

Are the Pale Blue ones OK? Any other recommendations or ones to stay clear of?

Thanks

timmmay

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#3327359 3-Jan-2025 20:56

Would it make more sense to get a lithium battery which may hold its charge a long time, rather than rechargable?

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RunningMan

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#3327361 3-Jan-2025 21:01

Good point, it's partly just not wanting to be throwing out more rubbish, so something that's reusable is good.

I could take them out of whatever appliance so they don't go flat when not being used but was thinking it would just be easier to charge up whenever needed.

SomeoneSomewhere

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#3327363 3-Jan-2025 21:20

Rechargeables usually have worse self-discharge than primary cells. It's all but guaranteed that if you put it in a drawer, it'll be empty in two months.

9Vs are a pretty crappy type of battery in the first place.

RunningMan

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#3327364 3-Jan-2025 21:32

I'm not too worried about having to charge for an hour or something to get a bit of use when needed, but having to go and buy new ones or wait for delivery is something I want to avoid.

I agree though, 9v batteries should be relegated to the past. Go for a pair of AAs or something more common instead.

timmmay

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#3327365 3-Jan-2025 21:37

I have a label maker I have to take a battery out of otherwise it goes flat in a couple of months. With one battery out the batteries last years.

Maybe you just need to get a battery with low discharge near the equipment you need to power?

Rickles

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#3327391 4-Jan-2025 09:41

Some years ago I used rechargeable 9V batteries for model planes and R/C cars ... just got them from JayCar (Varta brand I think), and used an Energiser charger (on special at Warehouse at time).

Worked well for at least a year ... always took battery out when not being used.

1101

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#3329750 9-Jan-2025 22:39

RunningMan:

Are the Pale Blue ones OK? Any other recommendations or ones to stay clear of?

Looks like they are lithium . Quite expensive .
Lithium batts are ruined by letting the voltage drop too low . Not sure if these have batt protection circuit to prevent that , I somehow doubt it.
I see they recommend NOT using them in smoke alarms

If you buy a good brand of Alkaline batts, they have a VERY long shelf life .
Just take them out of the device when not used .
The good quality alkaline 9v batts in my multimeters seem to last a long time when not in use . They el cheapo 9v batts didnt
So, I guess just buy some good alkaline & dont bother with rechargeable ?

https://www.pbtech.co.nz/product/BATPAN2010/Panasonic-6LR61T2B-long-lasting-Alkaline-Batteries

Modern Nimh dont have the self discharge issue any more , at least not as bad (LSD Nimh).

sudo

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#3329977 10-Jan-2025 11:47

https://www.marine-deals.co.nz/batteries/usb-rechargeable-9v-lithium-battery

Ten bucks at the moment

nitro

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#3329994 10-Jan-2025 12:50

SomeoneSomewhere:

Rechargeables usually have worse self-discharge than primary cells. It's all but guaranteed that if you put it in a drawer, it'll be empty in two months.

9Vs are a pretty crappy type of battery in the first place.

modern rechargables are much better at self-discharge. sanyo eneloop set a high bar. but yeah, 9V batteries are horrible. anybody who has split one of the alkalines open would have seen six AAAA cylindrical cells inside (I've never split a 9V energizer lithium, so don't know what's inside that).

of the ones mentioned, the one from marine deals has a higher capacity 650 mAh vs Pale Blue's 500 mAh, but Pale Blue mentions low self-discharge. the terribly low capacity is what puts me off of this. low self-discharge will still be a bigger percentage off 500 mAh than it would be of 2000 mAh AA batteriues.

every now and then I pick up a device only to find its 9V battery has gone flat. around midnight, last night it was my ethernet cable tester. more often it's the multimeter.

SomeoneSomewhere

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#3330003 10-Jan-2025 13:06

6xAA batteries is way bigger than a 9V, so the capacity reduction is to be expected.

Duracell lists their alkalines as being ~360h at 2mA (720mAh), 9.5h @60mA (570mAh), and 1.75h @250mAh (440mAh), scaling off graphs.

neb

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#3330051 10-Jan-2025 16:45

You can get decent-quality 9V lithium rechargeables, just make sure you get ones that aren't USB-rechargeable because they generally have rubbish charging circuitry. The batteries are just a stack of LiIon packs internally with some control circuitry, and last at least a year between charges. Or at least I recharge them at the start of the year and they've still got a good charge on them.

larknz

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#3330065 10-Jan-2025 17:17

RunningMan:

Anyone here use 9v rechargeables? Just want some for those seldom used appliances and tools that need one and have always gone flat when you need it (looking at you IR thermometer & scales).

Don't currently have a charger, so that would need to be factored in.

Are the Pale Blue ones OK? Any other recommendations or ones to stay clear of?

Thanks

larknz

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#3330067 10-Jan-2025 17:22

I have some Pale Blue 9v batteries for my irrigation controllers. Their life is rubbish. I need to recharge them every 2-3 months, whereas I could get 6 months out of a non-rechargeable battery. This wouldn't be so bad but I have to reprogram the controller each time.

mdav056

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#3330128 10-Jan-2025 22:01

I have 9v PaleBlues in my watering system, and they hold up fine -- I'm very happy with them. I also use a bunch of AA and AAA PaleBlue, and I'm very happy with them too (and some more of the same types that I bought from AliExpress, at a much cheaper price (Daweikala) and they are great too). The PaleBlues are assembled in China (they say) so, so probably much the same.

I suspect PaleBlues from the US will become more expensive when they have been Trumped.

gml