ORIGINAL: apalsson
ORIGINAL: TimBle
I'd opt for a LiFePO4 through a diode or BEC to drop the voltage under 6V. They're not as unreliable as NiMH cells under load.
Sorry Tim but with the utmost respect, that is nonsense. Where does this keep coming from?
1. An Rcexl ignition places very little load on the battery (200 - 400mAh) where the rated discharge current of NiMh (Eneloop) cells is in excess of 10C
2. It has been established more times than I care to remember, a 4-cell NiMh (Eneloop) battery is probably an optimum power source for these ignitions. They typically have a capacity of 2,000 - 2,300mAh which easily gives you 4 - 5 hours run time at wide open throttle
3. Running at 6V only increases the power consumption of the ignition (therefore heat dissipation) but doesn't give any better spark (these are digital devices)
4. I fail to see how it can be of an advantage to use a battery with nominal cell voltage above the safe operating voltage of the ignition and then use a semiconductor to drop the same voltage down to a save (yet marginal) level
If I had a dollar for every time I have seen this have to be explained, I'd be better off than I'm now
The nonsense comes from this->
The dis-advantages to Nimh are as such...
1) Nimh is dated technology
2) Nimh requires maintenance, i.e. discharging for maximum output
3) Nimh are prone to false peaking
4) Nimh need to be slow charged
5) Nimh are used by old farts
6) Nimh heat up when charged
7) Nimh can explode when charged
8) Nimh are prone to dead cells
9) Nimh need a fancy charger
10) Nimh need different delta v settings for temperature variations
11) Nimh self discharge, although this is less prevalent with eneloop technology
The advantages to Nimh are as such...
1) Nimh have the perfect voltage for spark
2) Nimh do not require a regulator
You did ask...