Charging the 8pack for nady and amp

B

Bartrak

New member
I have a question on charging the 8aa batery pack, do you use a 12v or 9v or take them out and charge them in a AA charger of some type?

I have a second question also, I bought a used Nady 151 vr and do not have any paper work with it. There are two holes on the side of the receiver, one say mute and the other says output level. I can see there is probaby a pot for adjustement but how do you set them? I have tried downloading a owners manual from Nady but it is grayed out and want download.
Thanks
 
I took the 8 individual AAs out and put them in my old charger all of about twice before I cannibalized a wall wart from some long-forgotten telephone or calculator or ??? 9V device. (This one put out about 11 volts @ 200 mah--they're usually stamped with the charge rate-- so when the pack is fully discharged I let it charge up for about 12 hours).

Nowadays you also have the option of buying a "smart" fast charger that will determine the voltage of the pack when you first plug it in, fast charge the pack in a couple of hours, and not overcharge.. There's been some discussion that these will either heat the spring wires or melt the plastic of an 8 cell AA battery holder, but I haven't found it to be the case. Any faster chargers, like the 15 minute R/C race-car variety, and I'd expect I'd need a welded pack instead.

I soldered up my own convertor plug, in this case a cord with standard DC power plug female socket on one end and a 9V transistor type battery tab on the other. (Note that most if not all of these 9V type tabs when store-boughten will not have wiring sufficiently beefy to carry the current we need,, so I also cannibalize dead 9V transistor batteries for the tabs and solder them up with 18 ga zip cord. (Unwired tabs also come in handy as safety caps when covered with a short length of fat heatshrink tubing.Which is a really good idea as loose 2.5 amp 10.8 volt battery pack has enough juice to give you one heck of a burn when shorted with change in your pocket or could easily start a fire in your truck).

The output pot on the Nady will come into play when you use an amp, if you start to experience clipping at high volumes or with deep bass sounds or at high volumes. Trial and error.

The mute pot is more sensitive and it is for eliminating radio frequency interference in RF "noisy" environments. Be judicious in it's use as it can kill the range. Better to find one on a channel without interference in the first place!

LionHo
 
Thanks lionHo
I have a couple 9v chargers and checked the output on them and one 9.03v and the other is 9.73v I also have one that is adjustable from 3v-12v and it puts out 12.03 on the 12v setting. I guess I could use a resistor if I was smart enough.

I know what you mean when you speak abot the pack gettig hot. I had a pack made up with fully batteries that were charged on my camera charger, I had a 9v snap cap with wire dangling. Well my Grandson decided to wire them together and you know the rest of the story,I had to buy another holder.
 
Yeah, you'll need a higher voltage than 9.7VDC to charge 8 AA NiMH cells to capacity, but that 12 volt one might be a little on the high side. Without knowing how the charging rate things could get a little dicey unless you want to closely monitor the voltage and heating of the cells manually the first few times. (I find that NiMH take a deeper charge after a few full cycles).

Might want to look into one of those voltage sensing Universal chargers, they have voltage cutoff circuits that prevent burning up the packs and they fast charge, too.
 
Mr. LionHo, Let's say I had one of the AA 8 cell holders filled with 2200 capacity NiMH batteries powering a Velleman amp into a small horn speaker..... About how long of a run time could I expect out of the battery pack? I know a lot depends on temperature, volume being played, and other factors. If'n I was to set the caller outside under *average* calling conditions at 8:00 AM and let it play, about what time could I expect it to stop playing due to low batteries? lol. I guess I could try this test myself but thought you might have some insight to this already. Thanks
 
Another question. What is the advantage/disadvantage of using an AA 8 cell holder filled with 2200 capacity NiMH batteries versus a premade NiMH battery pack for RC cars rated at 2200? Thanks buddy.
 
I don't tend to let my battery pack run flat like this but find I get something like three and a half or four hours of pretty much continuous calling with my 6" cone speaker caller. Which is less efficient than your horn, so you'll likely get more run-time at a given volume.

This is enough for most of the calling that I do . Remember, I'm a photographer, so I rarely get more than a couple hours of calling in in the morning and a couple in the afternoon, when the light is best.

The advantage of the loose AAs in a holder wrapped in gaffer's tape is that I can pop them out to use them in my Nikons F5s which eat batteries breakfast lunch and dinner. My flash units, and flashlights are standardized on AAs), AA NiMH are sometimes found for cheap on sale, and I always know what brand of cells I'm getting. I can pop them in my Energizer 4 cell 15 minute fast charger in my truck, too. And if only one cell in a pack gives up the ghost, it just gets swapped out. I must have close to 100 of them in various devices and packs.

Disadvantage is you wouldn't want to 15 minute fast-charge them in the holder, they'd get to hot for the plastic.

And I really don't have any problem with how you might be doing it differently.

LionHo
 
It'd probably work, but my sense is that it's not so auto sensing if you have to select voltage ranges? Though it has a wider range of output voltages than the one I have. It's not going to be a fast charger for NiMH at 500mah, a full charge on a 2500 mah NiMH pack would take 5 hrs at that rate, in a perfect world. Are there other variations or versions of this? (They mention only LiO or LiPo batteries in the ad copy.)

Price is about right, however.

LionHo
 
There is a smart universal charger at the same place for $16.95 on sale. It says it's good for any 7.2 volt to 12 volt Ni-mh or NiCd battery packs. I would think that should work.
 
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