Charging batteries Bought 7 sets of these walkies. Installed the batteries and put on charger. The batteries charged the recommended time but only register a quarter charge when you turn them on and only last about 4 hrs with minimal use. We bought more re-chargable batteries thinking we got bad ones with the units and charged them on a regular battery charger . When we installed them we have the same problem.

I don't know what model of radio, but here is what I would try: pull the batteries and charge them on the charger by themselves if your charger allows this. The lights, well, some manufacturers just miss the boat. Especially on low end or "beginner" radios. I have one brand I can insert with NO BATTERY and the light comes on. Talk about useless. Charge times vary by size of battery and charger output, minimum is 3 hours, 12 hours much more likely but I see a lot at 5-7 hours. Hope this helps, model and brand helps always.

Here are a handful of things which could be the problem:
1. Check to be certain you have the battery installed the correct direction. With this radio, it is a common mistake to put the battery in backwards. The Motorola logo w/name should be facing forward, and with the radio in an upright position, you should be able to read the words on the battery.
2. Check your charger. The red light should come on and stay on during charging.
3. Clean all battery contacts gently with a pencil eraser to remove dirt/dust/hand oils, then try charging again. If you are using a wall plug charger only (not a drop-in) you may have a problem with the jack on the radio.
4. Check your radio to be certain it is set to the correct frequency and PL code. It must be set identical to your other radios in order for them to communicate with one another. If you need help with this you can give us a call at 800-872-2627, and we'd be happy to walk you through SP21 programming over the phone.
Best regards.

Probably time to trash and purchase new.
Try Cobra tech support directly here: Support Cobra Electronics Corporation

Generally when a radio shuts off when you press the PTT button it is a sign of a bad or poorly charged battery. It takes more energy to transmit than to receive. The fact you have a charge which the light does not come on indicates you have a bad charger or bad connection between the radio and/or battery and the charger. Clean your battery contacts (on both radio and charger) with a pencil eraser and see if it clears up the problem. If not, you have either a battery or charger problem.

Best regards.

You might try cleaning the battery contacts and the charger contacts with a pencil eraser. It could be you are not getting good connection. Also check your batteries to see they are installed correctly and are touching the internal battery contacts to the radio. Try switching the battery pack to the opposite radio, as a test to see if one will turn on. It would be highly unusual for both radios and/or chargers to fail at the same time. So the problem is probably something simple.

I have the Cobra Microtalk 4100 FRS radios with charging base. After changing the batteries with new nimh rechargables the charge light would not illuminate and the unit would not charge. I noticed the original batteries had a metal band around one end. This band makes a small connection inside the battery compartment on the first battery. Seems to be a cheap way to ensure you dont try to recharge the unit with non-rechargable batteries installed. I rapped a small piece of tinfoil around one end of the first battery in the new set then popped it back in and now they will charge correctly again. Dont try this with non-rechargable batteries! I would recomend buying original replacement batteries.

Downloading the manual will now make the batteries charge?

apimom

Hello mironas3,

A general rule of thumb when dealing with rechargeable battery packs is to take the capacity of the battery divided by the charge rating of the charger and then add an additional 10%.

Offhand I am not sure what the voltage / capacity or voltage / charge rating of the battery and charger are but you can determine that by examine the labels on both items. Let’s say (for example) that your battery is listed as 7.2 volts and 1,000 mAH and your charger is rated as 9 volts and 100 mA. (These are just theoretical examples. Substitute the numbers from your own items.) You would divide 1,000 mAH by 100 mA to equal 10 hours. Then add 10%. So you expect a full charge to take around 11 hours time.

Of course, actual charge time will vary depending on how discharged the batteries are when you start charging them. Since the charger that Motorola provided doesn't have a charge indicator determining when the batteries are done charging is a matter of making an educated guess. If you touch the batteries while they are charging and they feel warm to the touch, that's a pretty good indication that they are done or nearly done charging as once the batteries are topped off excess power will turn into heat. (Note that batteries in a charger should never be HOT. If they are ever more then just slightly warm, something is wrong with the battery or the charger or both.)

Also, just a word of warning here: remember to always use the correct manufacturer recommended charger. Substituting a charger with twice the charge rate to charge the batteries in half the time is not a good idea. Rechargeable batteries are meant to be charged slowly. Fast chargers exist but they typically have built-in circuitry that pulses the charge rate to prevent the batteries from overheating. Using the wrong charger can result in damage to your battery or radio or worse could possibly even lead to a fire.

Best Regards,
Ken
"Go Ahead. Use Us."

Your LXT350 is equipped for using an optional rechargeable NiMH battery pack which can be recharged by inserting the AC adapter into the radio charge jack, or with the optional desktop charger.

I would make sure the radio is off, then insert the charger. Charge only for the prescribed time (no more/no less) and remove from the charger.

Charge time is initially 24 hours. Charge time is about 12 hours thereafter. For maximum battery life, it is recommend charging the battery pack when the low battery icon comes on. Remove the radios from the charger when the charge time expires.