uniden home patrol and nimh batteries

[Essexscan]

MTS2000des I agree on the NiMH batteries especially since the Good quality LSD cells have come out and a good quality charger that can charge each cell is mandatory but will keep cells active for a long time. Definitely saving the chargers cost in battery life in no time

 

[UPMan]

a) You cannot reliably detect charge full state of a NiMH battery at less than a C/2 rate (C/1 or greater is actually better for detecting overcharge using delta-v inflection point full charge detection).
b) You cannot reliably detect charge full state of NiMH batteries charged in series at any rate of charge because the delta-v inflection point will occur for each cell at different times, masking the charge state for any one cell (and especially to the group of cells as a whole).
c) It is normal for NiMH batteries to become warm during normal charge (before overcharge begins). Unlike NiCd batteries, which are endothermic during charge and only become noticeably warmer during an overcharge state, NiMH batteries are exothermic during normal charge.

So, scanners (all scanners, AFAIK) use a low charge rate combined with a timed cutoff to limit overcharge. The low charge rate (designed as C/10 for the supplied batteries) allows typical NiMH batteries in good condition to be safely recharged in the scanner. In the event charging continues past a cell's full capacity, a C/10 rate is low enough that the excess charge can be dissipated as heat with minimal impact to the cell's overall life per overcharge event.

As noted by many, the best way to ensure full charge with minimal overcharge when using NiMH batteries is to use an external charger designed to charge and monitor individual cells at a rate of C or higher. However, the methods used in scanners is also safe and reliable (but not as convenient when you need to rapidly cycle a set of batteries).

 

[NWI_Scanner_Guy]

Especially since i use the HP1 as my weather alert radio now too, this thread remined me to find the 12volt adapter plug and keep it in with the HP-1. The extra set SouthSide keeps you running just in case the charger turns off/power outage/fuse blows. just a little extra cheap insurance plus you never know when a battery may go bad, you'd go from 2 sets to none if the set inside need charging and you have 3 good charged cells and 1 bad one, the extra set gives you time to fix/troubleshoot. Don't forget when you get your new HP-1 to update the sentinel software-firmware and database to bring up to date. then get ready to have fun. Welcome to the HP-1 club

Thanks! I'm looking forward to using this amazing scanner. Will update the firmware and database to bring everything up to date, but am going to hold off on the Extreme Upgrade for a month or so to see how it all goes.

 

[digitalanalog]

With all that being said.

When I want Power, Performance, Reliability and Longevity out of a Battery I don't use NiMH
and it's a fact and not my opinion that there is a Much Better battery all Ready Being Used My Many other Electronic Industries, and they use the other type Batteries for the reasons I listed above.

Good luck with your NiMH .

 

[NWI_Scanner_Guy]

With all that being said.

When I want Power, Performance, Reliability and Longevity out of a Battery I don't use NiMH
and it's a fact and not my opinion that there is a Much Better battery all Ready Being Used My Many other Electronic Industries, and they use the other type Batteries for the reasons I listed above.

Good luck with your NiMH .

I don't have a dog in this battery type fight, but I'll admit I'm curious as to what type of battery you are referring to. If I could find something that provides longer life, I'd definitely consider using it.

 

[UPMan]

He's almost certainly referring to Lithium Ion. A battery technology that provides much higher power density (i.e. for the same size/weight, more capacity).

However, LiIon is much more expensive, requires much more expensive charging circuitry, and is not easily interchangeable with commonly available alkaline batteries for "emergency" power. We've considered it as an option, but one of the biggest complaints about the BC250D/BC296D were their use of proprietary battery packs. The battery system (including charger) would also be about 10 times the cost of providing the current solution.

 

[oft]

"....So, scanners (all scanners, AFAIK) use a low charge rate combined with a timed cutoff to limit overcharge. The low charge rate (designed as C/10 for the supplied batteries) allows typical NiMH batteries in good condition to be safely recharged in the scanner. In the event charging continues past a cell's full capacity, a C/10 rate is low enough that the excess charge can be dissipated as heat with minimal impact to the cell's overall life per overcharge event...."


The low charge current rate (c/10 or c/20) and the timing of cutoff is also used as a cheap and dirty way to regulate the internal temperature of the NiMH cell without having to use thermistors / thermal sensors because the internal cell construction of a NiMH cell is more sensitive to damage by heat/temperature than a NiCad batery.

 

[JASII]

Uniden Home Patrol And NiMH Batteries

Does anybody here have any recomendations for a good battery charger so I can recharge the NiMH batteries outside of the Home Patrol?

 

[simplec6]

Does anybody here have any recomendations for a good battery charger so I can recharge the NiMH batteries outside of the Home Patrol?

Maha is a well-known, reputable NiMH charger in the flashlight world.

 

[hiegtx]

Maha is a well-known, reputable NiMH charger in the flashlight world.

I'm using both a Maha charger, as well as a LaCrosse charger. I'm primarily using the low discharge batteries, and have multiple sets for the various scanners, as well as a couple of Canon digital cameras that use AA size batteries.

 

[nickyb11091]

Not to bring up a dead thread but I need some more clarification. I bought 4 AA Li-On batteries and I don't want to cause damage to my radio. I have my radio plugged in via 12 volt through my car where my homepatrol resides. I don't often use battery power and I am not properly charging the Ni-Mh batteries which prompted my purchase of the Li-On. I was going to install them but my father said I should research the batteries before making the change. So, 1. Will using Li-On batteries cause problems to the radio? and 2. Will the batteries safely and properly charge through the radio via the 12 volt plug. I'm not an engineer, my extent of batteries is Ni-Mh you want to drain before charging and Li-On you want a constant charge.

Info about the batteries:
1.Model: TR 14500
2.Capacity: 1200mAh
3.Voltage: 3.7V
4.Li-ion Lithium Battery
5.No memory effect and a longer storage life than NiMH Batteries. Lighter weight and higher energy density than any other rechargeable battery. It is perfect for building battery packs for RC aircraft, RC cars, and RC robots. Can use special PCB ( protection IC) to build 14500 battery pack·
6.Warning: The voltage of full charge and cut-off discharge is 4.2V and 2.75V. Don’t heat, incinerate or reverse polarity.

 

[ST-Bob]

The basic cell voltage is too different between Nickel Metal-hydride and Lithium-Ion batteries. A single-cell NiMH battery cell is similar to other AA size rechargeable batteries at 1.2 volts per cell while the Lithium-Ion batteries are around 3.6 volts per cell. As you stated, a fully charged Lithium-Ion cell is about 4.2 volts which is below what the radio needs to operate. 2 cells would be 7.2 volts rated and 8.4 volts fully charged. So a 2-cell Lithium battery is too high a voltage for the radio.

There's no good way to run a radio designed for 4.8 to 6.0 battery volts on a Lithium-Ion or LiPo battery pack. The voltages are just too different.

As for charging - no way. The Lithium chemistry requires accurate constant-current, switching over to constant-voltage charging to prevent heat, puffing and possible fire or explosion of the lithium battery(s). You cannot charge a multicell lithium battery pack in a series configuration without per-cell battery management (which the Home-Patrol, of course, lacks).

If I were you I'd stay with quality, low self-discharge NiMH batteries and charge them externally only. Set the charge time on the Home-Patrol to either 0 hours and charge them in an external smart-charger or set for only a low charge time of 1-2 hours to keep them topped up in the car. If you use the scanner on batteries, reset the charge time to an appropriate value for the amount you've discharged the batteries, then reset to 1-2 hours afterwards (or go the external smart-charger route).

As has been discussed here many times before, the HomePatrol and other similar devices designed to charge NiMH batteries internally do not have the proper circuitry to perform 'smart' per-cell charging. You will always risk overheating and scanner damage if you set the charge time wrong (too long) for the estimated amount you need to recharge NiMH batteries in a series configuration.

Unlike older NiCad batteries, NiMH doesn't have a linear voltage charge/discharge curve. Also unlike NiCads, NiMH has an exothermic charge response which generates a lot of excess heat. Without per-cell voltage and temperature monitoring, even NiMH cells are at risk for overcharging and radio damage. You can forget about Lithium batteries altogether - they're just too different and require even more specialized charging.

 

[RF23]

What strategies do you guys use to keep track of your batteries, do you use age or recharge cycles?

I have five handheld radios and the two that are transceivers will drain a supposedly fully charged battery pack in a few minutes of transmitting, in fact my cell phone has done that come to think of it.

 

[ST-Bob]

Info about the batteries:
1.Model: TR 14500
2.Capacity: 1200mAh
3.Voltage: 3.7V
4.Li-ion Lithium Battery

Let me be clear on those AA Lithium batteries - DON'T USE THEM!!!!!!!!!

4 X 1.2 volts is 4.8 volts for regular NiMH

4 X 3.7 volts is 14.8 volts - WAY TOO HIGH for the Home Patrol!!!!!!!!

And, of course, the Home Patrol won't charge them either. Forget it. I AM an Engineer so you can take this recommendation to the bank.

 

[nickyb11091]

Thank you very much Bob! Glad I didn't put them in there. I figured it would be an easy fix to my problem. I'll also check how long the charge time is set to on my radio. Thank you for the info!

Nick

 

[Jakeportland]

Thank you how long do I charge the batteries

 

[ST-Bob]

Jake, it depends on how much is remaining in the batteries. If they're completely dead, 2300 mah cells will require about 14 hours to charge in most scanners. However, as we've discussed many times, NIMH cells are impossible to charge in-series and be sure they're matched to each other. You should really use an external charger which measures the voltage of each cell and monitors its temperature. These smart-chargers will either turn off or light a certain color LED when they're fully charged. It's pretty idiot-proof.

Since this thread is about the HomePatrol and not the BC436HP, I can't tell you what (if anything) Uniden has done to the charging system on that scanner. On a HomePatrol, it's somewhat of a problem because you need to tell the scanner how many hours or how many mah to put back into the batteries. I still don't recommend doing a full charge in the scanner - I use the external charger and a spare set of batteries for 'instant' charging of the scanner.

 

[Dafe1er]

Jake, it depends on how much is remaining in the batteries. If they're completely dead, 2300 mah cells will require about 14 hours to charge in most scanners. However, as we've discussed many times, NIMH cells are impossible to charge in-series and be sure they're matched to each other. You should really use an external charger which measures the voltage of each cell and monitors its temperature. These smart-chargers will either turn off or light a certain color LED when they're fully charged. It's pretty idiot-proof.

Since this thread is about the HomePatrol and not the BC436HP, I can't tell you what (if anything) Uniden has done to the charging system on that scanner. On a HomePatrol, it's somewhat of a problem because you need to tell the scanner how many hours or how many mah to put back into the batteries. I still don't recommend doing a full charge in the scanner - I use the external charger and a spare set of batteries for 'instant' charging of the scanner.

He made a mistake of charging the BCD436HP batteries in the Homepatrol unit. this is why he was asking. Thank you for helping him. I will copy and paste this in his thread.

 

[ST-Bob]

Well, if that's the only charger he has (I don't know why he doesn't just charge them in the BC436HP then) he can set the charge capacity to the same as is written on his batteries (usually 2300 mah). This will set the HomePatrol to 14 hours and will fully charge "DEAD" batteries in about that time, then the charger turns off till the next time it asks you whether to charge or not.

I wouldn't doubt there's some sort of charger built into the BC436HP though. Probably a series charger so I still would not recommend using the scanner to charge the batteries if you can avoid it. Wally-World has Energizer batteries and chargers for a pretty low price. I'd suggest this would be better than possibly having a meltdown in the $500 scanner from doing it wrong...

 

[Dafe1er]

Just what happened ST-Bob:
http://forums.radioreference.com/uniden-scanners/285105-uniden-batteries.html