Two sets running every other day for 10 months are likely done. I usually stop running a set when I notice the drop in performance and length of discharge. If your charger measures discharge capacity, you can see what they are holding when discharged after being fully charged. Anything less than 500 mAh is likely no longer good for racing. Sounds like its time for fresh cells. I usually buy 4 sets at a time. The PN 750s and Kyosho SpeedHouse 800s are both good.

Thanks Traveler2! I figured what I have are about done, so I'm on the search for their replacements. I am planning on 4 sets, and I was looking at the PN750 or Eneloop 800 by going what Others have said, but I will put the Speedhouse cells on the list too!

Take Care and Stay Warm Everyone!
Drew

Just curious...but, when you say "I charge after each use with a SkyRC NC1500 charger at 500mah", do you mean you're setting the charger to 500mAh? If so, have you considered that that's the "cause" of the 'problem'? I might be new to Mini-Z, but I'm definitely not new to charging batteries. In setting a charger, whatever the mAh level is that you program into its settings, that is the capacity you are telling the charger to "stop charging". When charging LiPo packs, if I set the charger to...say...5000, the pack I'm charging will typically have a "fully charged" capacity of 5,000mAh, give or take a few. Likewise, if you're setting the charger to 500, chances are, you're only charging those batteries to (approx) 500mAh...not the 900mAh capacity they're capable of.

When I charged my first set of NiMH batteries for my Mini-Zs, I made a similar mistake...I just plugged the charger in, popped the AAAs in, and started charging them. After they were (supposedly) "fully charged", I wondered why the capacity was considerably lower than the stated capacity. I even went so far as to type an email to the battery's manufacturer, complaining that they were defective, and that I wanted to exchange them. Thankfully, before sending said email, I decided to do a little research...and, in doing so, I 'discovered' where/how to set the charging capacity for my new charger (the included "manual" wasn't in English...but, o/l searching found an English translation), changed the setting to match the stated capacity of the AAAs, and charged (actually, I 'cycled') the batteries. And, in the end, they finally had the capacity stated on the batteries.

Try changing that setting on your charger, from '500' to '900', and see if that doesn't resolve your "problem".

I know Drew said 500 mAh, but I think he meant 500mA. The way most of the AA/AAA chargers work is you set the charging rate, in this case 500mA, and the charger charges until full. I charge at 500mA as well, and most of my health cells charge up to 700-900mAh of capacity. I haven't used the same charger as Drew, but you usually can't set the maximum capacity on these chargers, only the rate of charge.

With some chargers, that's correct...but, with others (especially higher-end chargers), you can not only set the charging rate, but also the capacity. From past experience, for most chargers where the capacity can't be set, they are usually programmed to match the capacity of whatever batteries that manufacturer produces. As long as that manufacturer's batteries are used, or others of the same capacity, there's rarely a problem...but, if higher capacity batteries are used in the same charger, there's a good possibility they'll only charge to the capacity of the previous batteries.

There is, however, one major exception to everything I just said - "smart" chargers. These are 'intelligent' enough to determine the capacity of the batteries. This also allows the charger to charge batteries of different capacities and/or different types (AA, AAA, etc) at the same time. I almost purchased one of these...except that I decided I wanted to follow the same charging pattern I use for LiPo packs, charging at a lower rate before racing starts, then charging at a higher rate between races.

Thanks Traveler, yes I meant mA! I had been up a few days and was a bit punchy on the key board! LOL
My charger auto charges and tells me how much the amount of power the battery took, so they are getting fully charged. Unless my charger is lying or dying, it's the batteries. I've run the cycling program on them and it helped, but they are still showing their wear. New batteries are coming.
Thanks for the Help Guys!
Drew

I run with a local mini-z club but will try the Mini96 challenge. I should be up and running with a stock and maybe 2wd open class cars sometime in January.

Class- 2WD Open
Date- December 31 2022
Location- Madison, Wi
Race Time- 323.21
Fastest Lap- 3.8s
Chassis- Atomic MRT
Body- Fiat 500 Abarth
Wheelbase- 94mm
Tires- Marka
Motor- GL 3500kv
Batteries- 360mah LiPo
Gearing- stock
Notes- Car was driving pretty decent today and got a nice run in. Still gotta stay off those walls. Happy New Year!!

https://youtu.be/MBjcOzY6f_c

Class-Box Stock
Date-12/29/22
Location-Winston-Salem, NC
Race Time-262.9
Fastest Lap-3.27
Chassis-MR-03 ASF
Body-McLaren F1 LM
Wheelbase-98mm
Tires-K30LH fronts, Marka V1R10 rears
Motor-Stock
Batteries-PN 750s
Front Springs-PN Red
T-Plate-Kyosho Carbon Med
Motor Mount-Stock MM
Dampener (If applicable)-None
Dampener Fluid (If applicable)-K 15k grease on top shock
Gearing-Stock Gear Diff/7T pinion
Notes-No changes from previous month. Car feels slower than usual, but couldn't figure out why.

Class-RM Porsche Cup Class
Date-12/31/22
Location-Winston-Salem, NC
Race Time-265.0
Fastest Lap-3.23
Chassis-MR-03 ASF
Body-911 GT1
Wheelbase-90mm
Tires-K30LH fronts, Marka 10 rears
Motor-Stock
Batteries-PN 750s
Front Springs-ATM Deep Blue (Soft)
T-Plate-Kyosho Carbon Soft
Motor Mount-Stock RM
Dampener (If applicable)-None
Dampener Fluid (If applicable)-None
Gearing-Stock Gear Diff/7T pinion
Notes-No changes. Only a couple of runs today.

Class-Stock GT 70T
Date-12/24/2022
Location-Winston-Salem, NC
Race Time-239.3
Fastest Lap-3.03
Chassis-MR-03 ASF
Body-Ferrari F-430 GT
Wheelbase-94mm
Tires-K30 radial fronts, Marka V1R10 rears
Motor-PN 70T
Batteries-PN 750s
Front Springs-PN Purple
T-Plate-PN CF #4
Motor Mount-PN 94-98mm v2
Dampener (If applicable)-PN DDS
Dampener Fluid (If applicable)-None
Gearing-PN 64p 10/54 Ball diff
Notes-No changes this month. Noticed chassis cracked and the antenna came off board. Transplant in order. Tried 6 different stock cars this month, but this one was my fastest again...

Stock
Date-12/28/2022
Location- California
Race Time-236.13
Fastest Lap-2.91
Chassis-Pn 2.5
Body- NSX
Wheelbase-94mm
Tires- R Marka 10. F PN soft slick
Motor-3500KV
Batteries- Enloop

This took so so so many laps to get done under 4 mins.

Box Stock

Date-12/28/22
Location- California
Race Time-254.45
Fastest Lap-3.13
Chassis-MR-030
Body- R8 (actually used my other R8 body but don't have a picture of it)
Wheelbase-98mm
Rear PN soft radials
Front PN soft slick
Motor-Stock
Batteries- PN750
T plate white fiberglass
Front springs red

Only did a few runs with the box stock car but all the laps in stock really helped. Wanted to try for a better run but the servo is having issues so this run with probably be it.

2wd open
Date-12/18/22
Location- California
Race Time-233.71
Fastest Lap-2.90
Chassis-GLR-GT
Body- Jomurema
Wheelbase-98mm
Rear PN soft radials
Front PN soft slick
Motor-3500KV
Batteries- 2S lipo

This car is super easy to drive and had a lucky clean run after only running it a few times.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

We had 7 racers posting in 4 classes this month, with some close racing. In Box Stock 1.7 seconds separated 2nd and 3rd and in Stock 3.2 seconds separated 1st and 2nd. And PoorBoy sweeps the top spots in all classes he ran (good thing I ran Porsche Cup)!

Box Stock
1st - PoorBoy - 254.5/3.13s
2nd - TAMAK - 261.2/3.25s
3rd - Traveler - 262.9/3.27s
4th - ShawnO - 290.5/3.62s
5th - PaulSW - 301.3/3.51s
6th - ap910 - 398.5/3.97s

Porsche Cup
1st - Traveler - 265.0/3.23s

Stock Class
1st - PoorBoy - 236.1/2.91s
2nd - Traveler - 239.3/3.03s
3rd - ap910 - 351.2/3.88s

Open 2WD
1st - PoorBoy - 233.7/2.90s
2nd - TAMAK - 248.9/3.12s
3rd - TomTheGeek - 323.2/3.80s

FTM goes to PoorBoy in his Open 2WD car with a 2.90 fast lap!

If anyone was late posting because RCTech was down, please post up and I will update the results.
Please check my tabulations and let me know if I made any mistakes or missed anyone. January layout is same as December, but running counter-clockwise!

Happy New Year and Cheers,
Traveler2