Can I mix rechargeable batteries of different mAh ratings?

Question

I have three types of rechargeble batteries - four 2700 mAh, four 2500 mAh and four 1300 mAh. My radio controlled car's controller requires eight batteries. Is it safe to use 2 types of battery?

Answer 1

Safe?  Yes.

Recommended?  No.  Here's why:

The 2700 and 2500 mAh batteries are so close, you'll never notice any difference unless you apply scientific testing methods to measure it.  But the 1300 mAh batteries will wear out in roughly half the time.  Once they're down, the others won't matter.  Think of it like a team of horses pulling a load.  It's not going much of anyplace if two of the horses are tired out and lying down.

Also, older batteries tend to wear down faster than newer ones, so you want to avoid mixing those, either.  Still, there is nothing unsafe about doing so.  Most importantly, try to keep your mAh ratings within 10% - 15% of each other to get the longest usage before having to recharge.