So, if he decides to go higher than 5000mah, he will need to go with a lipo.

Yea, I have raced RC since 1982. In the old days, the nicads or nimh batteries would spit and pop when over charged, but they would not catch on fire. I ran Lipos for the last 10 years and never saw a fire. Then the last 3 months of racing I saw 3 batteries catch on fire. In all the cases they were probably 20 feet away from me and I still felt the heat. Catching fire is probably a misnomer, more like exploding. So after that I bought a Bat-Safe battery box and I always charge in it. Watch some videos and these Bat-Safe boxes work. All three fires I witnessed were in Lipo bags and they really didn't do anything at all.

https://www.bat-safe.com/product-page/bat-safe

I believe, from what i have personally experienced, Lipos store better than NiMh batteries, but you have to keep them at the right storage charge. I have some cheap lipos that are 3 years old and still work fine. I also have some that started to puff because I didn't regularly check the charge on them, and they puffed after the first charge after being stored for over a year. NiMh batteries, they never lasted more than a year in storage. I would pull them out, charge them, then get a couple minutes of run time, at most.

In the racing scene, those lipos get abused like non-other. Of course there are going to be some fires.

beautiful graph. Towerhobbies had during their clearance sale, a Dynamite 6 cell NiMH 4500 mah pack on sale for $12.77 from $39.99. Its technically still orderable, but it says shipment date unknown. I bought one to use in my Tamiya cars with molded battery tubs and so my son could safely charge it himself with a MRC 959 charger that I have left over from the old days. So far it runs great and has enough punch to get his clodbuster front wheels in the air with stock motors! I regret not buying a second pack.

Towerhobbies Dynamite 4500 mAh stick pack

So I checked some of my batteries today after being Stored for awhile. I had a couple that were reading 23% total and the cells were ready around 3.75.

Had my newest 4s Were ready around 50% total with cells ready around 3.80.
One of the cells on one was reading like 3.76 and others were 3.80-3.82

3.8 is great for storage mode. And about the cells being not the same that’s normal when a lipo sits. A quick balance charge will even them up.

What about those in the 3.7s and is 23% charge Not bad since they been sitting in Cold for awhile?

Most consider 3.6-3.8v per cell storage mode. You can also just put them on the charger and use storage mode. That will even the cells for you.

3.7 is fine. The only thing I'd be slightly concerned over is that one cell is a bit lower than the others, but a balance charge should sort that out.

Ok thanks I never charge without doing a balance charge. I balance every single time. I just hate having to store them in my shop in the cold. But I will not bring them in our house.

Storing them in the cold is fine, some people store them in a fridge. Just try to let them get back to room temp before charging them if they get too cold.

I just can't figure out why those dropped to 23% cause I'm pretty sure I charged them all to 50% When I stored them

We only race in the winter. My batteries stay in our fridge from April through September.

That's normal. It's why you shouldn't store them while discharged.

Anyone know of a 2s shorty with over 5000 mah that weights less than 190 grams in stock? Exalt has a 5200 that weighs 176 grams and Team Powers made a similar pack but I can’t find either in stock. Are there others like this? Also, why do batteries with the same capacity vary in weight so much? An example is the reedy 4800 shorties - they make two of them - one weighs ~205 grams and one weighs 165. The C rating is different but I’ve read that rating is kinda bogus. Do they really have the same capacity? Is the lighter one likely to fade quicker?