Originally Posted by
HappyGene
Hey, Rc_Dude, that's what I need to know about!
IR was always a big deal with NiCd's & NiMh's; so, although the performance is much greater, it looks like the same rules mostly apply.
No matter what it is, if you increase the resistance and maintain the same current, it will produce more heat in total. Then volume, mass, surface area, and airflow around it all play into how much and how quickly it will heat up temperature wise.
Originally Posted by
HappyGene
About your chargers, are they both advertised as "intelligent?" I've read about fast charge curves being in some chargers' chips with an ending 15-20% descent into voltage dominance vs. current. Sounds like the bike charger has a faster descent, if any.
Do you use a manual loading/reading and hand calculate IR or do your chargers have it built in?
They are both advertised as intelligent. The iCharger 1010 has the IR function built in and is the one that once one cell hits 4.2 volts it adjusts the current to hold it there. The less voltage sag/rise the battery has, the quicker current drops off. My Hitec Ultima x2 does the same but it's based off the batteries total voltage and has a function built in so the the voltage it reads the batteries voltage plus the charge current times some constant (Vc=Vb+C*A). So when the battery is at 4.05-4.1v/c it thinks the battery is at 4.2v/c and starts slowing down. This is a cheap safety factor to help ensure the cells don't exceed 4.2v but it still allows it to if one cell is far off balance.
This is why I like the iCharger brand chargers a lot better than HiTec, problem is iCharger doesn't make a duo 10A charger and sometimes has problems with surge current running off a car battery or LiPo...
Another thing is my HiTec charger's LCD display misspells works/characters all the time. Turn it on and it reads chargerer or dischchar or storge instead of charge, discharge, and storage. Change the mode and come back and they will usually fix themselves. The thing just doesn't feel sturdy at all.
And lastly, this is my second Ultima x2 after the first was returned due to an OBSESSIVE C term (slowing down at 3.8v/c and only charging to 4.05 or so) in that equation above.