Baofeng Charger Voltage Question 8.4v?

[rtorella]

I have two Baofengs, a UV-82HP + BF-F8HP. 10v in from the wall supply to the cradle. Have read 8.4 volts out on bottom of charging cradle. Two diff charging units and when I check voltage at battery contact points on inside of cradle, multimeter says 9.4 volts. Not seeing 8.4 volts anywhere. I also have 2 backup chargers and cradles, 1 for each radio. Same with them, multimeter says 9.4v. Tried another meter, same numbers. Anyone tell me where the 8.v volts comes in?

Another question?? Purchased the USB charging cable for Baofeng cradle. 10v input and when I check voltage at cradle battery contact point, multimeter says 9.70 volts rather than 9.4. Not enough diff there to worry about damaging the cradle or battery. Tried USB thru 13.8 power supply with cig lighter USB adapter, then plugged USB into my laptop, and finally USB thru Wall power supply that has USB plug on it. Tried with both Baofeng Radio charger bases. In each attempt, multimeter read 9.70 - 9.75 volts. Even my laptop USB port worked which surprised me. They claim that the 5v USB steps up to the 10V requirement for Baofeng cradles. 9.7v reading was great news.

I am still trying to figure out where the 8.4v volts comes in that is written on the bottom of the cradles??
Any of you experts help with explaining the 8.4 vs 9.4v confusion?

 

[DickH]

Any of you experts help with explaining the 8.4 vs 9.4v confusion?

The 9 volt readings are with NO LOAD.
When the radio is in the charger the voltage will be 8.4.

 

[rtorella]

Good to know

Thanks for your reply as that is great news.

73

 

[Rred]

The load/no load voltage will also vary depending on whether a charger is digital or analog. A digital circuit can be made to hold the output level regardless of load, while a cheaper older analog design (transformer) will have a much larger no-load voltage. Analog has no RFI problems, so it ain't dead yet.

I haven't looked at how sophisticated BF chargers are (and don't expect much(G) but in modern charging circuits, it isn't just the voltage that is controlled. A "smart" charger also looks at the battery temperature (4-lead circuit, like Motorola) and at the amperage being drawn, and cuts back voltage and amperage, based on the charge state of the battery, as determined by voltage and amperage, and limited by temperature.

It only looks easy. Although, there are all sorts of "computer charge controller in a chip" solutions on the market, really dirt cheap, if the manufacturer wants to use them.

 

[Comp-100]

The load/no load voltage will also vary depending on whether a charger is digital or analog. A digital circuit can be made to hold the output level regardless of load, while a cheaper older analog design (transformer) will have a much larger no-load voltage. Analog has no RFI problems, so it ain't dead yet.....

Calling the circuit digital is incorrect. I think you are trying to describing switching supplies vs. straight linear supplies. Switching supplies are more efficient and generally regulated, but not always to a super accurate level. A linear regulator can easily be added to an analog power supply and there will be no voltage variation load to no-load. Baofeng adapter is certainly switching supply based on size and weight. There is their adapter and then their charger base between the wall and the battery.

You are right voltage is of little interest unloaded because once loaded with a battery it will be adjusted based on the state of the battery and the charge profile used. With Li-Ion or Polymer cells the charge is fairly complicated if done correctly, but as you say there are different chips that can handle the complicated stuff as long as the input and heat management is properly done then they will work very well with few components.

One other reason for the voltage at the charger to be higher than one might expect is because many packs still use diode protection, and there may be other protection circuits inline, that introduce a voltage drop which must be compensated for.

There have not been a lot of issues reported with the Baofeng chargers related to their electronics so I'm sure they are basically fine.

 

[rtorella]

I appreciate your info. I recently purchased a W&W Mfg UC-1 Universal Charger, advertised that it works "with all brands". It has every combo of charging types built in to the circuit board. Temp, voltage, overload, etc etc. I purchased two cups which go in the unit, 1 or each model Yaesu HT. Out of 5 new battery packs (all new), this expensive smart charger would not properly charge any of the new NIMH battery packs. I logged each attempt and tried twice with each pack. Had to send it back after waiting 5 months to receive, after initial order, as they were relocating. Turns out, W&W Mfg does not make the charger or cups. A company in Iowa does. I have other low cost smart chargers that successfully charge all packs without a problem. W&W Mfg asked me if my batteries were "their brand". Told them no and their ad states "all brands and company batteries". I am staying away from the high cost "does all" smart chargers! Like newer cars, to much technology and electric components to fail. I purchased a $35.00 smart charger on Ebay (from China) for my Yaesu and it works as it should. Battery charges and never gets hot. Full charges even my Eneloop 2550mah pack. With the Baofengs, I have a UV-82HP + BF-F8HP. Both use a 10v wallwart and charging cradle. I have several battery packs for each radio, all with diff mAh capacities. For an $8.00 wallwart and charging base, they all work at 100%. I have put them thru diff tests. Even fully charged battery pack, waiting until the next day and put back into the charger. It immediately went into charge mode, ran for a short while, then the green charged light came on. The pack was not even warm to the touch. Checked with my multimeter and voltage was exactly where it would be after charging a depleted battery. The Baofengs charge at 400ma, which is slower than a smart charger, however, most likely better for the pack. This ruled out "timer" charging and indicated to me that the little cheap charger base has some sort of "smarts". It knew the voltage of the almost fully charged pack and when it was topped off. That is smart enough for me. There is also a USB cable for the Baofengs for charging USB to cradle. I purchased one and did not expect it to work. The USB cable steps the voltage from 5v up to the 10v for the Baofeng charging cradles. I tried it with both Baofeng model charging cradles, and had 9.7v at the charging contacts in the cradle. Then the 8.4 volt goes to the battery pack. Tried the USB cable in wallplug with usb plugins, also USB car cig lighter plug and finally with the USB plugged into my laptop computer. All were sitting at exactly the correct voltage at the charging contacts. No variance in any connection types. I was surprised to see that the cheap cheap Baofeng charging cradles work as they should. The USB cable has the charger base plug on the other end, which is universal with all Baofeng radios. I have two mint Yaesu HT's that never leave my house, FT-530 and FT-50R. I purchased the Baofengs just to see, as they are inexpensive when compared to $45-60 per battery for my Yaesu's, the Baofeng packs run approx. $15-18.00. I paid $18 for a 3800mAh and the Baofeng packs are all Li-Ions. So, the Baofeng chargers work great, providing the input is 10v not 12v. I have seen people grab a cable online that advertises works on Baofengs. However, those DC cables do not step down to 10v. Hook one of those up to the cradle and things get toasty right away and fry the charging base. Chief complaint with Baofeng chargers has been only can charge batteries with wallwart made for base. However, the USB cable for Baofeng adds much needed charging capabilities and flexibility that honestly I do not have for my older Yaesu's. Really surprised me for the low cost of these units. I am not advertising for Baofeng, just saying that they work for the price paid. And I do not have to worry about one of my mint Yaesu's walking away. 73

 

[rtorella]

Comp-100 thanks for your input as well. I am not up to par with electronics. More of a plug it in and hope it works. Have not had any problems with the Baofeng chargers. Have seen several others who were attempting to plugin a 12v DC plug into the charger base. Baofeng for some reason is 10v input. so the advertised DC Baofeng cables passthru whatever the source voltage is. Had that happen to me. Purchased a DC cable, works on Baofeng. Checked voltage at charging contacts and was sitting at 13.8v! That will certainly fry a Baofeng charging cradle. They are still selling them on eBay and it still says works with Baofengs!

 

[Rred]

Comp-
You're right about digital/analog. It is just most common that the analog wallwarts are unregulated, as opposed to the switching supplies and fancier ones.

rt-
There's a lot of hokum in the battery business, since most consumers have no way to tell what they've got. A lot of fraud and a lot of cheating, so reputation counts. A really bad charger (or battery) can mean an explosion and fire. A simply bad one can cut your battery life in half or worse. A really good one...is worth what they charge for it, in the longer run.
What I love are the folks who make broken English and claim a 19 volt charger "works with all" 7.x volt batteries. Yes, I'm sure it does. Not while I'm around, much less while I'm sleeping.

 

[rtorella]

I use Batteries America brand for my Yaesu HT's and have never had any problems with the packs. There are many on eBay, we know the ones, they have cheap cells and no 1yr warranty. At least the brand I purchase use name brand cells. Those broken engrish (purposely misspelled) are certainly out there. The one which really concerns me is the advertised DC cig lighter plug "works with Baofengs". That puppies output is equal to the input. I purchased one and plugged it into my Baofeng cradle. Smelled smoke immediately, gee I wonder why? 13.8v into what requires 10v max! With a Li-Ion battery pack in the cradle. Unattended, I imagine that alone has potential for explosion or fire. So I applied for a full refund with eBay! They sided with the supplier from China! No refund! So I emailed the seller and shared the news! Does not work with Baofengs and a hazard. This person in China actually understood what I was saying and agreed that it would in fact, not work with Baofengs. I promptly received a full refund. They did not change the description and currently still selling to fools.

 

[Comp-100]

yes there are lots of issues with cheap chargers and counterfeit batteries. Love the latest scam that used flour and a small cell. The problem is even when a charger works it maybe shortening the life of the battery. The only way to be 100% sure is monitor a complete charge from a number of different starting points. Baofeng though has enough users and have been around long enough that we can be pretty sure they are basically ok chargers.