Battery Packs

[Lscott]

How many people test their battery packs for capacity? Buying the cheap Chinese packs you can't really be sure you're getting what you paid for. There are documented cases of battery packs that are rated for more than the actual cells that are used internally. I see people questioning the common UV5R battery packs, for example, where people have noted the standard included pack has been marked with several different ratings.

I use an electronic load to test my battery packs, and use the OEM charger to ensure I start with a "fully charged" pack. Some people have a combo battery pack tester, reconditioning and charger system.

Having several portable radios with spare battery packs can get expensive. The cheap Chinese Lithium Ion packs run anywhere from a low of $20 to $25 and up to almost 2 to 3 times this amount. The real OEM packs are really expensive.

 

[mbrun]

I bought some inexpensive equipment to do this and have done it in the past but I do not do it regularly. Years ago I purchased a large lot of high-capacity D-Size rechargeable batteries that I ended up seriously questioning their capacity. That was a motivator to buy some hobby-grade items for this purpose. I confirmed the batteries were only a little over 50% their rated capacity, even after break-in. They all got returned and replaced with a different brand and model. The alternative lot all tested to 90% and greater of rated capacity.

Below is the unit I used. It is capable of measuring Volts, Amps, Amp Hours and Watt Hours, in and out of the battery. While it is not a laboratory grade instrument by a long stretch, it is good enough to get you in the ballpark.



Michael
WRHS965
KE8PLM

[Lscott]

Do you know what the lowest voltage that unit will function at? I have something like that from Powerwerx but when the battery voltage drops too low the meter quits working. For the 7.2 to 7.4 VDC nominal battery pack voltages i deal with it didn't really work.

  https://powerwerx.com/watt-meter-analyzer-inline-dc-bare-wire

I've purchased a lot used hand held radios and many came with battery packs. Almost universally the seller stated they have no idea what condition the battery packs were in. Also you find battery packs at the Ham swaps with the same caveat. 

I think I spent a week testing battery packs after I got the electronic load. The E-Load is also good for testing solar panels and general power supplies out.

You confirmed what I've read elsewhere about people getting burned purchasing battery packs that don't live up to the capacity claims. Without testing you have no idea if you really got what you paid for.

 

[mbrun]

Do you know what the lowest voltage that unit will function at? I have something like that from Powerwerx but when the battery voltage drops too low the meter quits working. For the 7.2 to 7.4 VDC nominal battery pack voltages i deal with it didn't really work.
  https://powerwerx.com/watt-meter-analyzer-inline-dc-bare-wire
I've purchased a lot used hand held radios and many came with battery packs. Almost universally the seller stated they have no idea what condition the battery packs were in. Also you find battery packs at the Ham swaps with the same caveat. 
I think I spent a week testing battery packs after I got the electronic load. The E-Load is also good for testing solar panels and general power supplies out.
You confirmed what I've read elsewhere about people getting burned purchasing battery packs that don't live up to the capacity claims. Without testing you have no idea if you really got what you paid for.
 

You’re right about getting burned. The average consumer only has what the supplier claims for capacity and knows no better. Nowadays you can count on many trying pull a fast one on you.

The meter I have can be powered by the battery it monitors or it can be powered externally. If an external power supply is used, it needs to be 10-30vdc. I use a 12vdc supply. I forget what the cutoff voltage is when using the monitored battery to power the unit but I vaguely recall 8 or 9vdc.

It looks like the majority of this class of meter is designed for solar, marine and RV applications. The hobbyist gets to benefit from their low cost availability so that is nice.

I may just have to create a jig that allows me to check the various radio batteries now in my arsenal to see how they fair.


Michael
WRHS965
KE8PLM

[Lscott]

1 hour ago, mbrun said:

I may just have to create a jig that allows me to check the various radio batteries now in my arsenal to see how they fair.

I thought about doing that too. I have several different types where each would need it's own jig. I'm just too lazy to build them. Now if I had a 3D printer, that would be a different story. That's at the bottom of the "toy list" with the spectrum analyzer, RF signal generator and Bird power meter with slugs ahead of it. Waiting to see if the government mails out any more "stimulus checks" to help out with the financing. 

[WyoJoe]

54 minutes ago, Lscott said:

I thought about doing that too. I have several different types where each would need it's own jig. I'm just too lazy to build them. Now if I had a 3D printer, that would be a different story. That's at the bottom of the "toy list" with the spectrum analyzer, RF signal generator and Bird power meter with slugs ahead of it. Waiting to see if the government mails out any more "stimulus checks" to help out with the financing. 

If you have several radios of the same type, each with a drop-in charger, you might be able to repurpose one of the chargers for this application. For instance, I have several UV-82 radios, so repurposing one of the chargers I have wouldn't be a big deal for me. I question the capacity of some of the radio batteries I've bought over the years, but even more than that, I question the capacity of many of the 18650 batteries I've seen for sale. Many claim to have a 4500 mAH rating (or higher), but are priced quite a bit lower than others claiming a 2500 mAH rating. If they claim to get much above 3500 mAH, then I take the rating with a grain of salt, because that's about as high as I've seen the ratings go for the higher quality brands. In general, I've found that if the price seems too good to be true, then it is.

I've also seen similar claims for the "lumen" rating of flashlights. Most of the ones I've seen on Amazon and eBay appear to be overrated. Perhaps they only achieve their rated output when powered by a 9000 mAH 18650 battery.

[serrasalmus]

as i have many years in the rc hobby i can not agree more, ive gotten tons of ccb off of amazon and have only found 1 brand that was up to the demands of hardcore racing and bashing. they where around for a few months and now there gone, however that battery is still killin it 4 years later and hundreds of cycles. i dont have any cool lab gadgets but i do have a very good lipo charger for the hobby that tells me alot of info. the scariest part to me is those 6 and 8 cell lipos that are ccb and the QC is horrible...i saw a 8 cell that was only taped instead of soldered one the connector, they used liquid tape on it....i mean thats 30 freakin volts and huge amounts of amps, good thing they ran a xt90 instead of the ec5 so i soldered it on and told them to be carefull with it....was so scary.. 

Lscott have you done any testing on the panasonic or samsung 18650 cells, at one point i was going to make me a few 2 cells for my fpv goggles, but i stopped flying when they went batstuff crazy with drone rules.

[Lscott]

10 hours ago, serrasalmus said:

Lscott have you done any testing on the panasonic or samsung 18650 cells, at one point i was going to make me a few 2 cells for my fpv goggles, but i stopped flying when they went batstuff crazy with drone rules.

I don't have any single cells to test. What I do have is a pile of used battery packs for radios. I must 20 to 30 battery packs of different chemistry types. Maybe 30 to 40 percent actually test at 80 percent or better under my test conditions. Some tested as low as 21 percent, garbage.

 

If I did have any 18650 cells that would be an interesting test to do. The whole test thing is automated through the E-load. Once it's setup I just start the test and walk away.

[Lscott]

11 hours ago, WyoJoe said:

If you have several radios of the same type, each with a drop-in charger, you might be able to repurpose one of the chargers for this application.

That won't work with the Kenwood battery packs. The charge contacts isolate the battery from accidental discharge. There is an isolation diode inside. I have to go directly to the radio power contacts to do the rating tests.

I suspect most radio battery packs are designed this way. If not then its dangerous. Sticking a radio in a pocket with metal coins or a key ring/chain won't end well in that case.

[WyoJoe]

13 hours ago, Lscott said:

That won't work with the Kenwood battery packs. The charge contacts isolate the battery from accidental discharge. There is an isolation diode inside. I have to go directly to the radio power contacts to do the rating tests.

I suspect most radio battery packs are designed this way. If not then its dangerous. Sticking a radio in a pocket with metal coins or a key ring/chain won't end well in that case.

Good points all around. My thought of using the drop in charger would be gutting pretty much everything internal and only connecting leads to the charger's contacts, which could then be tied to the battery analyzer.

[Lscott]

The blocking diode is built into the battery packs, not the charger. Modifying the charger wouldn’t do any good.

[WyoJoe]

4 hours ago, Lscott said:

The blocking diode is built into the battery packs, not the charger. Modifying the charger wouldn’t do any good.

That makes sense.

[Lscott]

As a point of reference the service manual for a Kenwood KSC-25 charger can be found here.

https://manuals.repeater-builder.com/Kenwood/ksc/KSC-25_B51-8626-00.pdf

Looking at the second page from the back it shows the circuitry for several different battery packs. I would imagine that battery packs from other manufactures likely do something similar.

The "charging terminals" on the base of the battery pack is only accessible by the charger base while the "discharging terminals" are only accessible by the radio when it's installed.

One thing about the Lithium Ion battery pack schematic are the cells are shown connected to a boxed area. That is a "protection" circuit. I noticed when running pack discharge tests using a simple power resistor, before using the E-load, if I discharged the Lithium pack much below the 6VDC I use for a cut off point the voltage will suddenly drop to zero.  Lithium batteries will be permanently damaged if discharged below a certain voltage level. The protection circuit disconnects the cells internally from the discharge terminals to prevent this.

[OldRadioGuy]

We should also be worried that cheap Li Ion batter packs do not have proper safety circuits built into the pack.  That vast majority of (legitimate) Li-Ion powered products require the safety circuits to be built into the battery pack.  If the battery pack has a legitimate CE mark it probably does.  But with all the counterfeit stuff you can't trust the label either.  They may have not safety circuit at all.   (BTW, this does not apply to NiCad batts)

I've had a lot of bad experiences with off-brand Li-Ion camera batteries either not charging fully or not holding charge at all.  Being very small batteries, they are less of a fire safety risk - but still a risk.  Now I buy only major brands, if not the camera brand. 

Vince

[Lscott]

9 hours ago, OldRadioGuy said:

We should also be worried that cheap Li Ion batter packs do not have proper safety circuits built into the pack.  That vast majority of (legitimate) Li-Ion powered products require the safety circuits to be built into the battery pack.  If the battery pack has a legitimate CE mark it probably does.  But with all the counterfeit stuff you can't trust the label either.  They may have not safety circuit at all.   (BTW, this does not apply to NiCad batts)

I've had a lot of bad experiences with off-brand Li-Ion camera batteries either not charging fully or not holding charge at all.  Being very small batteries, they are less of a fire safety risk - but still a risk.  Now I buy only major brands, if not the camera brand. 

Vince

Excellent point. Battery packs are something people are going to buy sooner or later. They don’t last forever. I wore out the lithium pack on my BTECH triband radio I use at work as cheap scanner while working in my office. 
 

Scan all day, then recharge overnight. After about a year it wouldn’t even make it through 8 hours before the radio shut down due to low voltage on the pack.

The typical life of a battery pack is 300 to 500 charge/discharge cycles. Depending on the owners radio use a battery pack might last one to several years.