Issues charging the VX-8R battery, 3 ways

[ke7vvt]

1. Regular wall adapter that comes with the radio - downside, you can't transmit at full power

2. cd-41 cradle charger - downside, will let the battery die if the radio is left on.

3. car charger - downside, the radio gets really hot.

Anyone else notice these things?

 

[KE5MC]

Yes and No

Item 1 - Standard fair for 500 ma chargers. Swap out the AC for cigaret lighter charger or DC power supply with more amps.

Item 2 - Not sure that makes sense assuming charger is connected to power. Usually my 8 is off when I put it in the charger so I really never noticed.

Item 3 - Car charger can supply more current for charging which will create more heat. Most of the smaller HT running at 5 watt get comments in reviews about the heat on long QSO too.

Item 2 is the only comment I see that doesn't fit the norm.

Mike

1. Regular wall adapter that comes with the radio - downside, you can't transmit at full power

2. cd-41 cradle charger - downside, will let the battery die if the radio is left on.

3. car charger - downside, the radio gets really hot.

Anyone else notice these things?

 

[Moleculo]

Yes and No

Item 1 - Standard fair for 500 ma chargers. Swap out the AC for cigaret lighter charger or DC power supply with more amps.

Item 2 - Not sure that makes sense assuming charger is connected to power. Usually my 8 is off when I put it in the charger so I really never noticed.

Item 3 - Car charger can supply more current for charging which will create more heat. Most of the smaller HT running at 5 watt get comments in reviews about the heat on long QSO too.

Item 2 is the only comment I see that doesn't fit the norm.

Mike

Agreed.

There is an aftermarket charger available that I saw at Dayton. They make interchangeable sections for different radios that all plug into the same drop in charger. I think they were $65

 

[gaucho]

I got a 2amp DC cigarette lighter adapter from Radio Shack with the yellow tip and run it off my Power Supply. It works great for charging and transmitting full power when needed.

 

[ke7vvt]

Tried the cd-41 cradle charger again last night. Left the radio on, both bands (Menu Item 79 RX Save = off) for about 12 hrs. Radio was off, green light was on, pulled it out and the radio wouldn't turn on. Dropped it back down and the red light turns on. Plugged it into the regular charger and turned the radio off, the battery was "Charging" and completely dead.

By my calculations, the radio draws more from the battery (just monitoring) than the charger puts into it.

Can someone else confirm this please?

 

[KE5MC]

vvt,

Not questioning that you are having a problem, but your issue with the charger is the only one I have heard of.

In the following quote I am not sure of your configuration. Could you explain the complete connectivity from radio to power supply during the failing condition and after you reconnect to get it charging again.

When you left both bands on was APRS enable on the B side with beaconing enabled in auto transmit mode? That would be the only condition that I believe could compromise charging on the cd-41 with a power source not up to suppling the needed current.

Mike

... Plugged it into the regular charger and turned the radio off, the battery was "Charging" and completely dead...

 

[ke7vvt]

Plugging it back into the regular charger is just an easy way to check the status of the battery because it tells you how far along it is charging. The radio doesn't know it is being charged from the cradle because the battery makes the connection to the cradle.

So

full (mostly) charge battery + red light on cradle + radio on + ~12hrs = green light on cradle + dead battery

Take the radio out and it wont turn on (very dead battery), drop it back in the cradle and the red light comes on. (Also checked the status of the charge by plugging it into the regular charger, dead)

Auto tx aprs is off, as well as the aprs modem. And this is the cd-41 yaesu cradle btw.

Can you get yours to do this vyu?

Anyone have any ideas why this might be happening or why (perhaps) Yaesu wanted it that way? Is that normal for other cradle chargers?

And for the help vyu.

 

[KE5MC]

vvt,

I tried to post earlier, but the database crashed and I lost my post.

So...

I will try your setup and see what happens. It has been about an hour since I started. With radio ON I put it on the charger and it went into red light ON charge mode. AC wall wart, charger base and radio all warmed up as expected during this mode. At some point the battery reached a charge condition and the green light turned ON and all the components cooled off.

I think I can see where this is going to go. I am betting that the change in state from charging to charged is latched in the charger. In 12 hours I expect my battery to be dead.

Problem or feature??? I see it as a feature to protect the battery from overcharging. Li-ion batteries relatively speaking have a complex charging cycle and I think the design intent is that the battery has to be remove and reinserted to clear/reset the charging circuit.

I will get back to you in 12 hours.


Mike

 

[KE5MC]

Follow-up

I don't wait until the radio died.

After a few hours the displayed voltage had dropped a few tens of a volt. The green LED was still ON. I removed the radio from the charger stand, waited about 10-15 seconds and reinserted the radio. Red led turned ON and after 30 minutes it was obvious by temperature increase that it was in the charging mode.

In my test method I did not allow enough time for the radio to turn itself off. So it did not duplicate the original setup. I don't see that as significant. It does appear that the charged status is latched and the radio/battery must be removed to reset the circuit. This eliminates keeping the radio/battery topped off either on or off. Once charged status is indicated the charger is done until the next remove/insert cycle.

 

[ke7vvt]

Thanks for that vyu.

It is good to know the behavior of the radio/charger this way.

Good work.

vvt