Rechargeable Aa 1.5v Batteries

[rvpopeye]

BMS = Battery Management System ,, it keeps everything from going "flame city" and balances the cells among other mysteries I haven't yet discovered !  

I've never made (or worked on) one of those so not certain what they contain or if always active during discharge but think it probably is. (I really haven't done much tron work since retiring , taking a break from the solder fumes LOL....OK ,except for a couple of times on my solar stuff...)

I will be following this thread as I wanted some of the AAs for my other detector and a 9v for the pinpointer.... not a priority as yet. ( I have 5 sets of ni-mh AAs and a 4 block of 9v alkalines as I B a prepared pirate  arrrrrrrrrrrrrrrrrrrrrrrrrr)   

 

 

 

[mh9162013]

On 7/15/2021 at 5:23 AM, rvpopeye said:

Some charging circuits can produce HF interference. So checking is good , then you'll know .

Edit: Thought about this more today..

Plus there must be a BMS in each one , could be a "symphony" of EMI ?

Possibly different amounts between brands too.

Or nothing at all ?

 

Most likely: yes, yes and yes.

I used the Tenavolts in my Fisher F-Pulse for some brief indoor testing and I measured no difference with them and Eneloop NiMH cells. This doesn't surpise me as my Garrett Carrot works identically whether using a 9v battery or my AAA to 9V adapter (which contains a voltage booster).

As for my Garrett AT Max, I'm not going to use the Tenavolts in them. For one, I don't think my kitchen observations were a fluke. For another, even if it is a fluke, the AT Max is so sensitive to EMI and chatty, I don't want to use batteries in it that even provide the impression that they're altering my VDIs numbers and/or sounds. Also, the AT Max works just fine with Eneloop NiMH cells. I just thought the Tenavolts would provide a good weight savings. I may see if I can make a AAA NiMH pack to use in the AT Max though for times where I want it to be as light as possible (and am ok with a 2-3 hour run time).

[mh9162013]

21 minutes ago, rvpopeye said:

BMS = Battery Management System ,, it keeps everything from going "flame city" and balances the cells among other mysteries I haven't yet discovered ! 

Oh, these rechargeable lithium AA cells definitely have something going on to protect and manage the cells. Something needs to reduce the 3.6 or 3.7 nominal volts (and closer to 4.5v or so when charged) to 1.5 volts. Also, you need something to cut off the cell to prevent over discharge.

And the RnB packs likely have a BMS that does similar duties, including balancing the cells, like you mentioned.

[rvpopeye]

 I've been looking at lithium for my solar set up for some time now...

BattleBorn seems to be king ATM but those prices !

Battery tech is growing exponentially  , it's tough living on the edge of development .  But that was my life for SO many years !  Hard to break the habit now but I try. skuh kuh kuh kuh

 

 

 

[kac]

I did mean RnB. Other brand I have is AmpTorrent that have their own charger instead of the spaghetti plug on Black Ubes.

None cause any EMI to any of my detectors so don't think that is an issue. Performance wise the RnB last the longest, easy 40 hours on the AT Pro.

AmpTorrents and BlackUbes both have same output voltage output as alkalines unlike NiMH.

Best way to check it take them out in the field and bring a set of alklaines and test.

[Chase Goldman]

14 hours ago, Chase Goldman said:

BTW I don't think the internal electronics pack is doing any sort of buck-boost output regulation except perhaps when charging in which case there may be input voltage regulation. 

Yeah   I'm wrong about this.  I thought they were operating with a different Li formulation that produced 1.5 vdc but they are actually dual anode 3.7 VDC LiPo and 1.5 VDC buck regulated output.  It is plausible the transistor switching buck regulator creates EMI under load.