Why does RS reccomend 1600 mAh batteries?

[whooey]

Don't the 2500 mAh batteries last longer? I was wondering because in my Pro-97 manual, they reccomend 1600 mAh batteries. (RS brand of course)

Maybe they say that because the RS brand only goes up to 1600 mAh, not 2500...

Any input is appreciated,

Brandon G.

 

[UPMan]

Normally, it would be because the charge circuit in the scanner is designed for 1600 mAH batteries. You can use the 2500, but they'll take about 22 hours to fully charge them in the scanner.

 

[Voyager]

Don't the 2500 mAh batteries last longer? I was wondering because in my Pro-97 manual, they reccomend 1600 mAh batteries. (RS brand of course)

Maybe they say that because the RS brand only goes up to 1600 mAh, not 2500...

If the RS brand only goes to 1600 mAH, that would make sense. They don't want to tell you to buy cells elsewhere, and if they only have up to 1600, and recommend 2500, that is what they would be doing.

Does the '97 only come with 1600 mAH cells? Are they RS brand?

Not taking anything away from UPM's valid point.

Joe M.

 

[whooey]

UPMan must be right, there is 2000 mAh batteries on RS's website, so the circuitry must be for 1600mAh batteries. I dont charge in the scanner anyway, dont want to damage any internal components with heat!!

 

[scanbc780]

UPMan is exactly right. The manuals state 16hrs to charge. 1600ma batteries and they charge at a rate of 100ma if I remember correctly. That would give you a full charge on 1600mah batteries at 16 hrs. If you use larger cells just add aprox 1 hour for each 100mah over 1600mah. So 2500 cells would be 22-25hrs.


Brian

 

[DaveH]

UPMan is exactly right. The manuals state 16hrs to charge. 1600ma batteries and they charge at a rate of 100ma if I remember correctly. That would give you a full charge on 1600mah batteries at 16 hrs.
Brian

There is something referred to as charging efficiency, which is less than 100% so the rate would have to be somewhat higher...20-40% for NiCDs and NiMH is probably similar.

Dave

 

[Voyager]

UPMan must be right, there is 2000 mAh batteries on RS's website, so the circuitry must be for 1600mAh batteries. I dont charge in the scanner anyway, dont want to damage any internal components with heat!!

Well, I'm glad I qualified my comment with 'if'. :wink:

I agree - it's much better to use a charger dedicated to charging the cells. They can do the job faster and IMHO better. Aside from that, you don't tie up your scanner charging the cells.

As I've said on other forums, if you get a cell that goes bad, it can REALLY create a LOT of heat that can warp cases and damage components. It's much better to risk a $25 charger than a $500 scanner.

Joe M.

 

[Caesar]

yea, just to be repatitive but give my 2 cents as well, i use a dedicated chrager that gets my 2300mah batteries charged in about 30 minutes, and the heat it produces is not something i would want in my scanner, though i assume the scanner charnges much slower in order to greatly reduce the heat produced by the batteries chargeing.

but yea, just keep extra batteries and a quick charger and you'll never be left stranded, and best of all you can get the better batteries, like 2300mah, or however high they are now...

 

[oregontreehugger]

Your local Wally World probably has a package containing an Energizer travel charger and 4 x 2500mah AA batteries. It's not a quick charger, just the basic travel charger. Takes about 9 hours to charge the batteries, and you can do 2 or 4 at a time (as well as AAA's).

Cost is about $17. Been powering my 246T with them and getting awesome usage, about 12+ hours.

 

[EricCottrell]

Hello,

It is not listed on the HRO website but the Salem, NH store has a close out on the Maha MH-C204F charger/conditioner for $20. Includes a DC power cord, 4 2300mAH AA batteries, and case for carrying 4 AA batteries. It can charge two sets of two AA or AAA batteries independently. I do not know if it is a closeout at all HRO stores. They also have the MH-C204W charger (new and improved model) for $40.

I use the MH-C204F for my BC246T and other scanners and it works good. I have not gotten a chance to use it with my digital camera.

I have a digital camera so I am interested in comments about batteries and chargers for digital cameras. Scanners are not as tough on Batteries but some interesting observations.
http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM

73 Eric

 

[AZScanner]

Your local Wally World probably has a package containing an Energizer travel charger and 4 x 2500mah AA batteries. It's not a quick charger, just the basic travel charger. Takes about 9 hours to charge the batteries, and you can do 2 or 4 at a time (as well as AAA's).

Cost is about $17. Been powering my 246T with them and getting awesome usage, about 12+ hours.

Edit: I thought he meant the quick charger, not the slow one. My post is in reference to the quick charger.

I had one of these. Charged one set of two batteries. Went to charge a set of 4 and within about 5 minutes noticed a funny smell. Went to investigate and saw the charger venting SMOKE out of the top. :shock: I didn't even bother to take it back, I just pitched it in the trash right then and there. I refuse to buy another.

I use the Digital brand charger they sell instead. It takes an hour or more to charge a set of 4 2500mah cells, but I've run mine thru 1 or 2 cycles a day for about 8 months with no problems at all. I recommend that one instead.

-AZ

 

[DaveH]

Just want to pass on a caution about some of these cheaper chargers. I picked up one that charges at 300mA per pair (not especially fast, but OK) plus four 2000mAh cells for $15 ($CDN) at a "discount" store.

First time, everthing worked OK; cells got a bit warm. One time I decided to do a "top-up"; bad idea! After a while the cells got horrendously hot. Surprisingly, they worked OK after that, but if left longer they might have perished.

Moral is, don't try a partial charge unless the charger is known to handle it. I keep a slow charger around and use it mostly, unless the faster charge is necessary. Batteries will last longer.

Dave

 

[bravo14]

Hello all,
I use 2000mah for my pro 96. It is harder to close a bit but it works good last up to 13-14 hours that is non stop. I do not charge the batteries from the radio. I use the quick charger just on case they decide to blow up in the radio. I have 1600mah they are hard to find unless they have some in certan stores. I have about 18 I use them for my pro 92 soon all my portables will use 2000. If I do I still keep the other for back up like the storms coming and use some alkaline batteries too. I haven't tried to use different brand chargerable batteries yet.

 

[PhilJSmith67]

The PRO-95 and 96 charge the cells very slowly, but it will charge them with the unit on or off. The slower you can charge *any* cell, the better. Heat takes away from the longevity of cells. My guess is that GRE designed the charging circuit this way, with a charging current that equates to effectively 100mAh per hour.

I haven't had any problems charging 2300mAh cells in my 95. The scanner gets mildly warm after approximately 20 hours of charging, and the cells never get hot. After that point, I unplug the A/C adapter. With the backlight on almost all the time, I can typically get about 4 to 5 days of use on a charge with the scanner on several hours per day.

I'll probably get a stand-alone charger in the near future. I know that once batteries get old, individual cells can start doing some funky things (as was indicated in a prior post here). I don't like the idea of having one cell flake out and melt the case, which is a distinct possibility after a year of using the same cells.

 

[Voyager]

Your local Wally World probably has a package containing an Energizer travel charger and 4 x 2500mah AA batteries. It's not a quick charger, just the basic travel charger. Takes about 9 hours to charge the batteries, and you can do 2 or 4 at a time (as well as AAA's).

Cost is about $17. Been powering my 246T with them and getting awesome usage, about 12+ hours.

The ones I'm talking about are made by Maha.

If you only need to charge pairs of cells:
http://www.nimhbattery.com/maha-mh-c204f.htm
Less than $19 and IS a quick charger

If you need to charge single cells (or sets of three):
http://www.nimhbattery.com/mhc401fs.htm


Joe M.

 

[DaveH]

The ones I'm talking about are made by Maha.

If you only need to charge pairs of cells:
http://www.nimhbattery.com/maha-mh-c204f.htm
Less than $19 and IS a quick charger

If you need to charge single cells (or sets of three):
http://www.nimhbattery.com/mhc401fs.htm

Joe M.

Good point Joe. Most chargers seem to charge only in pairs, which is not a problem for most equipment. Many FRS radios use 3 cells, so in that case best to get one that does single cells. The Rayovac model that does rechargeable alkaline, NiCD, and NiMH, while rather slow, does this, and has a charge LED for each position.

Dave

 

[slicerwizard]

The slower you can charge *any* cell, the better.

Not true. Slow charging means unavailable batteries. Slow charging NiCads promotes crystal growth, which leads to internal shorts. Very little internal heat is generated while charging NiCad or NiMH cells. Heat buildup occurs if cells are overcharged; that is a charger issue, not a charge rate issue. Cells that are warm to the touch are not being stressed. Nowadays they're dirt cheap - don't worry about getting every last cycle out of them.

I should add that slow charging methods often have no cutoff mechanism to stop charging when the cells are fully charged. The infinite trickle charge method is a good way to kill cells in a year or two.

 

[DaveH]

GE had a good reference book decades ago that described what you
are saying about crystal growth. NiCDs are designed to take a certain
amount of continuous overcharge without damage. I've had good long
life using slow charging, by NOT leaving them on overcharge for long
periods; giving them just enough charge within reason.

Couple of decades back I designed a charger that started out high
(0.3C, which was sort-of "high" at that time), then switched to low charge
by cutting off the charge for a short time and sampling the level; seemed
to work well.

Anyway, I'm not as familiar with NiMH, but I think they don't tolerate
continuous overcharge as well as NiCDs. Some people do it though, and
get away with it. I do that with my PRO-92 and the batteries only get a
bit warm, and their capacity doesn't seem affected after >4 years.

Dave