The JBL Charge 4 has a light that glows or blinks red when the battery is about dead. In the case of this speaker, this lamp is in the battery gauge on the front base. Sometimes though, this red light stays on or blinks for long periods. E.g. It starts flashing during play and does not stop, even when you connect a charger. And this is a problem since it generally means that the speaker is not charging. Thus in this post, we offer reasons that this can occur, and give possible fixes.
Why JBL Charge 4 Red Light Stays On
It’s normal that the battery gauge gives off a blinking red light when the battery is very low. But this red light should go dark when you connect the speaker to a charger, and battery recharging begins.
Normally though, this gauge only shows white lights. The number of these glowing lamps tells you how full the battery is.
All lights in this gauge go out when charging is complete.
Now the red lamp in this meter may not change to white or go dark when you attach the charger. If not, then several things might cause this. We list these below thus.
1.The Power Outlet May Not Be Live
The Problem
The adapter for the JBL Charge 4 may not deliver any power. Why? Because it is not receiving any to begin with. This can happen due to a defective AC or car circuit or tripped circuit breaker. A blown fuse, faulty wiring, or general power failure can also cause this.
The Fix
Check that your outlet has power by testing it by plugging in a lamp or other device. Reset circuit breakers if tripped. Also make sure to flip on any switch that controls the outlet you’re using.
2. Power Supply is Not Working Well When the JBL Charge 4 Red Light Stays On
The Problem
The red light stays on, or keeps blinking perhaps, because your adapter provides SOME but not ENOUGH current. Its output energy can fall over time. So it might not deliver the correct amount presently. Note that this speaker requires 2.3 amps at 5 volts to fully recharge in the specified time of 4 hours.
The Fix
Replace the adapter, preferably with a higher output model. We recommend chargers from Key Power, Belkin, and Anker, that deliver full USB power levels for this speaker.
3. The USB Charging Cable is Too Long, Too Thin, or is Faulty
The Problem
The USB cable can limit the charging current too much, even if your power supply is working well. This might happen with very long or thin cables.
The Fix
Use as short a cord as practical. Or, upgrade to a thicker, higher current handling cable. Hold cable lengths to six feet or less, and pick a cable certified to carry at least 2.3 amps.
4. The Battery in the Charge 4 is Bad
The Problem
As lithium ion batteries age, they lose their ability to fully charge. Plus, the charging current curve they draw changes over time. Normally, as a battery recharges, it draws less current. But in battery failure, it may draw the wrong amperage, thus confusing the charging circuits. Thus they might act like no charging is occurring. So, the red lamp stays on always.
The Fix
Replace the battery. But keep in mind that you can’t easily get to it in the JBL Charge 4. Indeed, changing the battery means that you must take the speaker apart.
But note that doing this likely breaks the water resistant seal. Thus the speaker will no longer be safe, should you get water on it.
Breaking this seal may also change the sound quality as well. So get someone to replace the battery battery who knows how to pick the right replacement. They should also be able to restore the seal to as it was, as they reassemble the speaker. A good battery should fit well inside and provide 3.6 volts and at least 7,500 mAh (27 watt-hours). But we suggest using only JBL certified batteries for this speaker.
5. The Speaker Might be Defective when the JBL Charge 4 Red Light Stays On
The Problem
Even if you have enough power supply, the current actually getting to the battery may be low or too high. This can happen when the battery management circuits inside the speaker fail. Note that these systems read the battery status. Then they shut off the charging current when they deem the battery to be full. So if they always detect a full battery, they may never start the charging.
But when they fail, the battery might get no power at all. Thus, it never recharges. Again, in this case, the red light might never turn off even with the charger connected. You may also see that the speaker doesn’t play as long before going dead. Or it might not play at all, except when you’re charging it.
The Fix
And finally, the best solution here, given the low cost of this speaker, is simply to get a new one. Also, the circuits in this model are quite small. So unless you can replace the system board(s) yourself, then again, just buy another speaker.