Need help with replacing a lead-acid sealed battery with a Lithium Ion battery

Click For Summary

Discussion Overview

The discussion revolves around the challenges of replacing a lead-acid battery with a lithium-ion battery in a small fan belt application. Participants explore potential issues related to voltage compatibility, battery protection circuits, and charging methods.

Discussion Character

  • Technical explanation, Debate/contested

Main Points Raised

  • One participant emphasizes the danger of using the same charger for both battery types, highlighting fire and explosion risks.
  • Another participant suggests that the motor may have a protection circuit that is incompatible with the higher voltage of the lithium battery.
  • A participant reports that the motor runs briefly when the lithium battery is connected, but then stops, while it operates normally with the lead-acid battery.
  • There is a suggestion to measure the terminal voltage during operation to diagnose potential issues with the battery or motor.
  • A participant expresses skepticism about the battery being dead since it is new and questions whether a smaller voltage battery would work.
  • Another participant inquires about the specifications of the lithium battery pack, particularly regarding built-in over-current protection.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the cause of the issue, with multiple competing views regarding the battery's functionality and the motor's response to the new battery.

Contextual Notes

Participants note the importance of understanding the battery's specifications and potential protection mechanisms, but specific details about the battery's design and the motor's requirements are not provided.

banglour
Messages
3
Reaction score
0
What I am trying to do is replace my 12v 5Ah lead-acid battery with a 14.8v 6600mAh lithium ion battery. It powers a small fan belt. And for some reason I can't get the lithium battery to work. Can somebody tell me what I might be doing wrong, or if it will even work?
 

Attachments

  • DSC05644.jpg
    DSC05644.jpg
    53.9 KB · Views: 527
  • DSC05648.jpg
    DSC05648.jpg
    46 KB · Views: 543
Engineering news on Phys.org
#1: Do NOT charge the Lithium battery with the same charger used for the Lead-Acid battery! This is a potential fire and/or explosion hazard!

As for the problem you're having... assuming the Lithium battery is fully charged, it's possible that the motor has a protection circuit that doesn't like the higher voltage. What exactly happens when you connect the new battery? Does it run if you reconnect the lead-acid battery?
 
Yes I have a separate charger just for the Lithium battery.

The battery is fully charges and when I connect the lithium battery and turn the motor on it sounds like it actual runs, but just for a split second. Then nothing happens after that. When I connect the lead-acid back up the motor runs just fine. Why is that?
 
Sounds some form of protection circuit either in the battery pack or in the motor (or of course a dead battery).

Can you please measure the terminal voltage while you test it. If the terminal voltage drops markedly when the motor stops ("after a split second") then there is a problem with the battery. Either a dead battery or some built in current limiting.
 
After I start the motor the terminal voltage drops all the way to 00.0. I have a hard time believing that its a dead battery because its brand new. Would it work if I got a smaller Voltage battery?
 
Do you have any specifications on the battery pack. Does it have any built in over-current proctection?
 

Similar threads

  • · Replies 12 ·
Replies
12
Views
2K
Replies
10
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 13 ·
Replies
13
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
4
Views
4K