BlueTooth speaker batteries question

[Welchs101]

HI,

I am taking about my bluetooth speaker as it quit working and i thought i would put "new" rechargable batteries in the unit and see if this fixed the problem.

When i opened the unit and looked at it i noticed that the battieries (both 18650 rechargeable batteries....3.7V) were connected in parallel (see enclosed picture).

so my questions are
(1) i have never seen batteries connected in parallel is this right? why do this
(2) the old batteries were 18650 3.7V 1800mAh and new ones i got are 18650 3.7V 2000mAh...........is this difference in mAh ok?

[CapLeaker]

Re: BlueTooth speaker batteries question

I don't see any picures

#2: That's fine.

[tibimakai]

Re: BlueTooth speaker batteries question

I also have a Sony SRS-XB2 bluetooth speaker, that suddenly stops, even when plugged in.
It could be a sign, that batteries are going out?

[Khron]

Re: BlueTooth speaker batteries question

I'd say that entirely depended on how things are wired up internally.

If all the input DC goes through the charger which then supplies both the circuitry AND the batteries, then that might be the case.

If it's more like in laptops (where the DC in powers the whole works, and some of that is tapped off to charge the battery), then there might be some other issue.

I also have a Sony SRS-XB2 bluetooth speaker, that suddenly stops, even when plugged in.
It could be a sign, that batteries are going out?

[Welchs101]

Re: BlueTooth speaker batteries question

i am enclosing a few pics.........
overall showing all the components...charger + speaker
another showing the speaker opened up and the batteries laying beside
and one showing close up of batteries

note:
(1) i did measure voltage coming out of charger and it was 5.17 V
(2) i measured the voltage across both batteries and "each" measured ~ 4.2V

question (1):
if batteries measured 4.2V are they bad? my initial thought was no but i dont know.

i am getting a descent voltage out of the charger so i would think its ok......so now i am not sure whats bad and whats not.

thoughts?

[Khron]

Re: BlueTooth speaker batteries question

5.17V is within the +/-5% "usual" accepted tolerance for things like USB power.

4.2V is what you'd expect from a fully-charged lithium-ion battery.

But that says nothing about the actual state / shape those batteries are in. If they're aging (or they were just crap straight out of the factory), their internal resistance may have climbed, and when the circuitry needs a bigger "gulp" of current, the voltage drops (Ohm's law), possibly below the brown-out level (or undervoltage cut-off) of said circuitry.