APX4000XH, which battery?

[N4KVE]

Just picked up an APX4000XH. The orange Canadian oil fields version. 800 & 900 MHz. I’m looking to get an extra battery. The radio has a decal saying use NNTN8750 battery, which I have. But I see NNTN4321 batteries which say they’re also for the same radio. Anyone know what the difference is? And these are different from the regular APX4000/XPR7550 battery.

 

[RadioDave95125]

I have an APX4000XH and can attest to the lack of information on its batteries. Short answer first, both the NNTN8750A and NNTN4321A work on the radio.
The battery originally specified for the radio was the NNTN8750A. They are very expensive if bought new and risky to buy used. The internal impres circuit places a small drain on the battery and if not periodically charged, they will kill them selves over time. Many of the used NNTN8750 batteries available on eBay may be no good if not stored a maintained properly.
The NNTN4321A is compatible with the APX4000XH, I have several and they work well. I’ve looked all over on line to find any information that says the NNTN4321A is a replacement for the NNTN8750, but never found anything. I only found one document that listed the NNTN4321A as an approved accessory for the APX4000XH.
The APX4000/XPR Mototrbo batteries are a totally different form factor and will not fit or work on an APX4000XH

 

[N4KVE]

Thanks man. The new battery that came with my XH is fine, but the 2 year old spare that came with the radio [both 8750’s] has no battery data when hitting batt in the menu. So looking for a spare, I realized there were 2 different ones. These batteries new from Moto dealers are $200+. But I have to wonder, since these were sold in Canada for the oil fields, how did so many get to the US?

 

[RadioDave95125]

You for sure need to have a few batteries on hand. The 2050mAh capacity rating that I rarely see charge higher than around 1850mAh isn’t much for the physical size of the battery, you need two to make it through a full day of active radio use.
Aside from the high cost and maintenance battery, the 4000XH is a really great radio…. solid built like its big brother 6000 and 8000 models, has excellent RF and audio performance.

 

[AJ1L]

I just picked up one of these radios myself. I’m taking a risk and trying one of these on eBay… We’ll see what happens.

Battery Pack NNTN8750-A Impres 2050mAh Li-Ion Motorola | eBay

You are looking at a Genuine Motorola ZEBRA Battery 82-111636-01 for MC9500 9590 Series Scanners. If such is the case, we will try all we can to replace the item with an identical item in working condition.

www.ebay.com

 

[N4KVE]

Hopefully it won’t have hundreds of charge cycles on it. But for that $, as long as it works it’s good as an extra.

 

[MTS2000des]

2018 date code. There were a lot of these on Fraudbay before from that time frame, and most arrived DOA and refused to charge in IMPRES chargers as their voltage got too low.

 

[AJ1L]

Yeah I’m not expecting a miracle, but the price has me willing to take the risk. I’ll report back once it arrives.

 

[RadioDave95125]

At least the seller has 30 day return policy - so if it's DOA, just return it!

I have studied numerous impres batteries. The batteries are dual cell Li-Ion, two cells connected in series to create a 7.4V battery. One critical flaw is the impres circuit appears to be powered off the center tap of the batteries as it is a low voltage circuit. This places a small leakage current on the lower battery cell and if not periodically charged, it will kill the battery over time. I did read a motorola document somewhere along the line that did state you must periodically charge NNTN8750 batteries at least every 6 months when being stored.
Sometimes you can trickle charge up a dead battery with a current limiting power supply set to 7.4V and bring it up enough to power the impres circuit so when you put it in the charger you don't get the dreaded red flashing light. I've managed to recover a few NNTN8750 batteries from the dead, but they never perform that well as the lower cell of the two cell pack is always compromised.

 

[chrismol1]

Theres some newer NNTN4321A on there with better dates codes but slightly higher price. I'd go with the better date code or something sold with verified usage data, some of the sellers include this. These things don't store well if they aren't used. I have a 4000XH, the battery 'leakage' is very noticeable if it isn't used semi frequently

 

[williewhyte]

NNTN8750 batteries for the APX4000XH should only be required if radio required to be CSA compliant in hazardous area for Canada.
The batteries issues are mentioned earlier apply, does not hold charge for a 12 hour period with minimal use. The radio build is not as robust as aAPX6000. We have found lots of issues with the casing and accessory ports. Limited options in the way of alternative antennas or batteries.

 

[N4KVE]

Ended up finding a NNTN4321 dated 2123 for $45, still in the box. The charging contacts look untouched, so hopefully it’s NOS. I’ll know in a few days.

 

[N4KVE]

Ended up finding a NNTN4321 dated 2123 for $45, still in the box. The charging contacts look untouched, so hopefully it’s NOS. I’ll know in a few days.

Looks NIB. Only shows 3 charging cycles, & dated mid 2021. Shows at 1900 ma.

 

[N4KVE]

I have an APX4000XH and can attest to the lack of information on its batteries. Short answer first, both the NNTN8750A and NNTN4321A work on the radio.
The battery originally specified for the radio was the NNTN8750A. They are very expensive if bought new and risky to buy used. The internal impres circuit places a small drain on the battery and if not periodically charged, they will kill them selves over time. Many of the used NNTN8750 batteries available on eBay may be no good if not stored a maintained properly.
The NNTN4321A is compatible with the APX4000XH, I have several and they work well. I’ve looked all over on line to find any information that says the NNTN4321A is a replacement for the NNTN8750, but never found anything. I only found one document that listed the NNTN4321A as an approved accessory for the APX4000XH.
The APX4000/XPR Mototrbo batteries are a totally different form factor and will not fit or work on an APX4000XH

I found this. It seems the NNTN8750 which is the battery that came with the radio discharges quicker vs the NNTN4321 battery. The two 4321 batteries both came fully charged with only 3 charge cycles on them. So it seems the 4321 battery is the way to go. The seller [Surplus Technology] has some NIB for anyone interested.

ACTIVE CIRCUITRY BATTERIES WITHOUT SLEEP MODE
The batteries listed below have a higher self discharge rate due to additional active circuitry required to meet specific regulatory requirements. For best performance these batteries should be charged and put into use within one (1) month of receipt. However, if storage is required, the batteries should be charged to a 100% charge state every 6 months.
ACTIVE CIRCUITRY BATTERY KIT NUMBERS
NNTN8570A NNTN8840 NNTN8750A NNTN8287 NNTN8386A NNTN8359A NNTN5510 NNTN7383
IMPRES Li-Ion 1250 mAh IECEx/ATEX IMPRES Li-Ion 2000 mAh IECEx/ATEX/M1 IMPRES Li-Ion 2050 mAh CSA
IMPRES Li-Ion 2300 mAh CSA
IMPRES Li-Ion 1800 mAh CSA IMPRES Li-ion 2075 mAh IECEx/ATEX Li-Ion 1420 mAh IECEx/ATEX
Li-Ion 750 mAh IECEx/ATEX
ACTIVE CIRCUITRY BATTERY STORAGE RECOMMENDATIONS
1. New batteries that will be stored should be charged to 100% state of charge within 1 month of receipt. Every 6 months, batteries must be recharged to 100% state of charge.
2. Batteries removed from service for storage should be charged to 100% state of charge. Every 6 months, batteries must be recharged to 100% state of charge.
3. Do not store batteries attached to radios or host devices. This will minimize current drain on the battery.
Note: Batteries removed from storage may take several charge / discharge cycles to achieve their optimal capacity. One or two reconditioning cycles will accelerate capacity recovery.

 

[RadioDave95125]

Another interesting aspect of the APX4000XH is the quiescent or leakage current the radio draws when switched off will also drain the battery. I don't know if this is just my radio or if all 4000XH models do this. The radio I have draws 2.314mA (at 7.5V) when switched off. This is a very high amount of off state leakage current. Most all motorola hand held radios (XTS, XPR, APX etc.) will draw a few microamps from the battery to power/keep charged the RTC backup battery and possibly a few other things. This leakage current is in the range of microamps and that would take a very long time to deplete a battery left on the radio and unused for a period of time. A 2.3mA leakage current on the other hand would deplete a 2050mAh battery in about 29 days by my rough calculation.
I found this out the hard way as I left a charged NNTN8750 battery on the radio and forgot about it for a while, next time I tried to turn on the radio the battery was dead, so dead I had to force trickle charge it with a power supply to recover it before the impres charger would charge it.
This lead me to measure the 4000XH input current when the radio is switched off using a Keithley 2430 source meter and found the unusually high off current. I would be interested to know if others see the same leakage current and it's not just my radio.
Moral of the story for me, not only will an NNTN8750 battery kill itself over time from impres circuit current consumption but the radio will also kill the battery even faster if stored for a period of time with the battery attached.

 

[N4KVE]

Trust me, if a radio will be sitting for a week, I remove the battery. And I only charge my batteries off the radio.

 

[chrismol1]

Same here I've had my APX4000XH with 8750 taken off charger with full charge, left on the desk and it's dead or around 2 weeks with no usage. There's also that problem with used 8750 ebay batteries. People were buying them a few yrs old and not used in long time and sometimes unable to resuscitate them

 

[RadioDave95125]

Like I said before, most motorola handheld's will draw some very light current from the battery when switched off. The APX4000XH just appears to be higher than others. My sample size is one, my radio. Would be interesting to know what others get on their radios. I did manage to get a copy of the detailed service manual to study the input power control circuit. However, there are no detailed schematics in the detailed service manual, it is not much more than a copy of the basic service manual so that was a dead end.
Just for fun, I measured the off current for a few other 900MHz radios I have and here are the results:
APX4000XH = 2.314mA (almost 24 times more current than other radios)
APX4000 (900) = 98uA
XPR7580 = 112uA

 

[AJ1L]

Follow up on the 2018 battery from eBay… As I expected, it would not charge when I got it, it was just flashing red. I know it can damage the battery, but I applied voltage to it for about 30 seconds and got it to start charging. It now works fine, showing 85% capacity when fully charged.

 

[kc1ho]

So I bought a couple NNTN8750's with 2017 date codes from theoutletdeal off eBay. My first problem was they were completely dead and needed to be jump-started to even take a charge. Once I got the batteries charged, they worked fine in my radio and it could read gas gauge data. Later I upgraded my charger to a PMPN4576A charger from a reputable dealer, and after I charged these NNTN8750's in this charger, now my radio says "Unknwn battery" when powering up. After a few more charge cycles in the new charger, now one of these batteries will no longer take a charge! Anybody ever see this before? Have any advice how to recover these batteries?

Note I have another NNTN8750 battery with 2021 date code that has always worked fine in both chargers, so I don't think there's anything wrong with the new charger.

So today I just purchased an NNTN4321 from Surplus Technology on eBay, hopefully I have more luck with this battery.