rechargeble batteries

[gambill1]

This is a 2 part question. On one of my scanners ( a uniden 330 ) it says use only 2300 mah batteries. I am currently using 2250 batteries. I know i can use less but can I use over the 2300 mah batteries?

second question.. the other scanner i have ( radio shack pro 82) really doesn't say what size I can use so would this matter if I use a larger capacity battery? for example a 2500 or 2700 mah battery?
any help would be appreciated. excuse the spelling.

 

[bob-the-scanner-man]

I don't think that the mAh rating is really that important. I'm assuming that these are AA batteries, if so, they have a standard output of 1.25v per battery. I believe that the mAh rating is a measure of how long the battery can maintain its voltage(and its charge) at 1.25v.

If you use over 2300 mAh the effect would be that the charge on the batteries would last longer than the 2250s. The same applies for your second question. The amount of voltage is what is important, and this is standard for all AA batteries so you don't need to worry.

For example, I have solar lights in my yard with 900 mAh AA batteries in them, it wouldn't hurt them if I put in 3000 mAh it may take longer to charge but would have a longer lasting duration. Both 900 and 3000 mAh AA's have the same voltage.

(I may be wrong on this, but I'm pretty sure its accurate.)

 

[kb2vxa]

Correct, milliamp hours (mAh) is simply the current over time capacity of the battery. You can go as high as you want, higher is better because the charge will last longer. For example, my 2M HT can be run off an external 12VDC source so when I was doing security at a hamfest and doing a lot of transmitting I ran it off a 7.5Ah gel battery that lasted all day.

 

[pathalogical]

You may also consider using a smart charger from Maha or LaCrosse. I have the BC 900 and when charging batteries it will tell you their capacity in mAh. Your batts may charge to, say, 1.4v each but if one reaches its capacity of 2300 mAh and the other only 1800 mAh, performance is limited by the weakest one.

 

[jackj]

This is a 2 part question. On one of my scanners ( a uniden 330 ) it says use only 2300 mah batteries. I am currently using 2250 batteries. I know i can use less but can I use over the 2300 mah batteries?

Yes, you can use higher capacity batteries but the charge time will be longer. I wouldn't worry about timing the length of the charge, the internal circuit should monitor the state of charge and adjust the time as needed.

second question.. the other scanner i have ( radio shack pro 82) really doesn't say what size I can use so would this matter if I use a larger capacity battery? for example a 2500 or 2700 mAh battery?
any help would be appreciated. excuse the spelling.

I believe the PRO 82 uses Ni-Cd batteries not NiMH. There is a difference in how the two are charged. First of all, Ni-Cd batteries have lower capacity, typically around 500-750 mAh versus 1800-2500 mAh for NiMH. Also most charging circuits will trickle-charge Ni-Cd after they reach full charge, an extended trickle-charge will ruin NiMH cells. Ni-Cd batteries are usually charged at 1/10th of their capacity rating for 14 to 16 hours (500 mAh cells are charged at 50 mAh). In no case should Ni-Cd cells be charged at a rate higher than their 4 hour charge rate of 1/4 capacity because of internal heating. NiMH on the other hand can be charged a faster rates provided that the state of charge and cell temps are monitored.

In short, don't substitute Ni-Cd's for HiMH's or vice versus.

 

[gambill1]

Thank you to all for the info.

 

[b7spectra]

Always make sure you have extra's on charge. I flat wore down my batteries in my 396XT at the Atlanta Motor Speedway on Saturday and I had brought extra NiMH's with me. Since I also do photography, I routinely keep 6 on charge, 6 in the camera and 6 in the bag - nothing worse than having batteries go dead and having no back ups!