Batboard

Is there a way to measure the capacity of batteries for a MT-1000? What is the expected life of NiCads, NiMH, etc? Any information would be definately appreciated.

bill in las cruces

[quote="k5msw"]Is there a way to measure the capacity of batteries for a MT-1000? What is the expected life of NiCads, NiMH, etc? Any information would be definately appreciated.

bill in las cruces[/quote]


There are a number of companies that make a device to condition the portable radio batteries. problem is they are kind of on the expensive side. Unless you have a number of batteries to run through, your probably not wanting to spend the $300 to $1000 for one of these boxes.

As for the expected life of a battery, that all depends. If someone leaves it in a trickle charger for a long time, you can probably kiss the battery good by. I have seen new batteries be cooked in less yhan a week.

If you treat the battery with care and only charge it when the cell voltage gets down to about 1.1 volts, then recharge it, you might get a couple of years out of it. I like the dual rate chargers that go into high charge and monitor both the battery temp and voltage during charge. They then switch over to a low charge rate when its done.

The charge / discharge cycle is about 300 to 500 times. May seem like a wide number, but there are too many variables to close it in.
Like was the battery fully dishcharged before putting it on the charger, or was it only used for a short time and then put on the charger. Was the battery real cold or real hot when placed on the charger? This all effects the battery life.

Jim

If you got any battery stores near by, like the batteries plus stores or something like that, they will test and evaluate a battery for a minimal fee. Some of them will even credit the testing fee towards a new battery if yours turns out to be crapola.

Otherwise, your going to have to find someone with a battery charger/conditioner. I use a Maha C777 Plus II charger/analyzer/conditioner that a friend owns when i need to test an unknown quality battery. It has a temp probe and monitors everything during charging and conditioning and give an overall capacity and voltage readout after a full cycle. They are not terribly spendy, roughly $90, and well worth the investment if you plan on using battery power often. If your using a portable radio daily then it might be worth the investment to get a charger that could help extend the life of the battery. Most OEM chargers seem to cook the battery, and if your not careful about charging time, and how often you charge it, the life will shorten quickly.

I like to use the Maha at least once a month with the OEM quick charger inbetween. This helps monitor the battery capacity and life. Though if i owned one myself i would use it as my primary and only charger.

If your using a Motorola 4633 quick charger, the type that has the charging and complete red and green leds on front, then there is a mod that can be done to keep em from over cooking the batteries. And it DEFINITELY helps! I can attest to that!

If your using a Motorola standard charger, either the type with a base and wall wart adapter, or the one that looks like the quick charger but only has the charging indicator and no complete indicator, then there isn't much you can do other than to keep an eye on it. I used to use a plug in timer between the charger cord and the outlet and set it to the number of hours i want it on. You can get them as lamp and christmas light timers, etc. That will help to prevent damage from accidently forgetting to remove the battery.

Oh, and if you have the Moto quick charger, 4633A,B,C, remember that when the complete light comes on the battery is only about 90% charged and needs another hour to one and a half hours to be fully charged. Don't leave it in for more than two hours after the complete light comes on. I'm working on hacking up a charger now so that the complete light coming on triggers a setable timer for unattended charging. If i ever get time to complete that project i will let everyone know how to replicate it.

Motorola makes a little battery guide. It contains part numbers for all Moto batts (including IDEN and cell) and some of the aftermarket batts they sell. It also has a good care and feeding guide for NiCd and NiMH batts. Part number is 6880309M45 and is available from parts (or sales) at no charge. Most Moto dealers and MSS's have them available-RRRobby

Great information----I have a couple of Motorola NTN4633B's -----what is the mod?

bill

Here is the mod from the BatBoard, not sure who the original poster was but it works like a charm. If you do this you don't have to worry about removing the battery within a couple hours of it lighting the complete indicator. I have one that i modified and accidently left a battery in it for three days straight, oops, but it never damaged it and the battery was cool because it was only receiving a small trickle charge.

Field Mod, Rapid Rate charger:

Brush any dirt or dust out of the cooling slots.

Locate R 14, should be a 2 ohm 7 watt "square ceramic" resistor and dress it as close to the chassis as possible for some heatsinking, verify it's value. Locate R 10, a 22 ohm 1/2 watt resistor on the board. Change R 10 to 62 ohms 1/2 watt.

Locate the capacitor, C 14, a 10 uF to the left of U3 near pin 3, remove it.

Put a battery in the charger and then power up the chargers AC. Upon power up with a battery already in the charger the charger should go into
the COMPLETE mode, green LED on. Remove the battery and put it back in, it should go into CHARGING mode, RED LED on.

You can verify the Rapid "CHARGING" and COMPLETE rate of charge with a voltmeter across R 14 , 1.8 to 2.3 volts DC in CHARGING mode, .05 volts in COMPLETE mode.

Now when the battery reaches full charge, the charger will trickle charge the battery in the COMPLETE mode, reducing any more heat build-up in the battery. You may leave a battery in the charger for up to 24 hours in the COMPLETE mode. If AC power is interrupted the charger will not go back into the RAPID rate upon power return.

I have a NTN4633C charger. Is the modification to prevent overheating already addressed in this version? Is this version suitable for charging the NiMH batteries without worry of frying the battery if left in the charger? Thanks for whatever advice you can give me. John

I had two "C" revisions that did not have this modification, and one that did. But perhaps a previous owner modified it.

Here is a full article on the modification. If nothing else pull it apart, easy to do, and see what you got.

http://www.repeater-builder.com/motorol ... r-mod.html

The article was compiled from the info i had as well as others.

Well, the C version charger as it came did not have the modification. But, success. With the instructions I was able to easily make the conversion. Thanks so much for the help. I am glad that I won't be sacrificing my batteries on the alter of overcharge.