Replacing Li-ion Battery

[WOJO]

Hello everyone! I am looking to extend the life of my portable speakers. Contained is a 14.8v (1050mAh) Li-ion battery. Can I purchase a similar 14.8v Li-ion and just connect it in parallel to the other battery to obtain a longer ON time, or will doing so disrupt my circuit?

Also, the input to the speakers is 12v, yet the battery is 14.8v. I would assume the circuit converts my input to 14.8v and then the Li-ion battery tells the circuit when it is full and does not need any more charge. If I connect another battery back, can I still use the same input to charge both of the batteries in parallel at the same time? Thanks for your time.

 

[davelectronic]

Hi WOJO.
Welcome to the forum.
Two batterys in parallel is not ideal, one, the weaker one will pull the other one down, there is always slight difference in battery cells, i would look for the same voltage, but a larger Ah (amp hour ) battery, it will take a bit longer to charge, but not much i doubt.

 

[WOJO]

Would it be possible to purchase a laptop battery such as this:
http://www.amazon.com/Replacement-dv7-1240us-dv7-2011TX-4HSTNN-IB75-HSTNN-DB75/dp/B006H0S676
And replace the battery that is currently on there all-together?
The one in the link is rated at 5200mAh while the one currently being used is 1050mAh. Does this mean the new one would last 5 times longer?

 

[davelectronic]

Yes i believe it would, but unless the charging circuit was modified it would take that much longer to charge i would think, and then you have connections etc, compatible or not, i dont know that.

 

[WOJO]

Awesome, thanks for the help!

 

[(*steve*)]

There are some issues with placing batteries in parallel. You can get one rapidly discharging into the other if a cell fails.

Better probably to get a larger battery and replace the existing one.

 

[WOJO]

I ordered this battery:
http://www.amazon.com/Enhanced-truC...Packard/dp/tech-data/B005JUOD7M/ref=de_a_smtd
I want to incorporate a battery level for this battery, but can't seem to find any information on what the range of voltage is between completely charged and dead.

Is there any way to determine what the range of voltage is besides testing it? I am following this tutorial to accomplish this:
http://www.electronicecircuits.com/electronic-circuits/lm3914-12v-battery-monitor-circuit

 

[davelectronic]

I cant see a problem using that circuit as a battery monitor, ive actually been looking for a circuit in one of my electronics magazines, i cant find it for love or money, i think its the same as the circuit thats in your link, so long as you can charge your extended battery, and charge it when it needs it, there should be no problem.

I was at a bit of a loss with some battery configurations, believing parallel batterys was not a good idea, i think its got its pit falls, but many design ideas have little issues, a half dead series battery will pull the other cells down, i found the link below interesting.


http://batteryuniversity.com/learn/article/serial_and_parallel_battery_configurations