That battery expert provided you with a pile of dung!
Undeniably battery life will be shortened with fast charging rates, that is a know fact from
Basic to Advanced Battery Information from Battery University that shortened life expectency is minute, if any.
That being said it is always better to charge low and slow. Unfortunately it may not always be feasible.
Once again that being said a good charger like a Pila or an XTar, will pulse the battery in the beginning to sort of wake it up for the lack of a better word. Depending on the charged state of the battery the charger will then charge the battery at a rate to support the "proper charging" of the battery. This rate will vary during the charge cycle. These chargers are also know as smart chargers. For example:
- The Xtar WP6II has 6 bays, divided in 3 bays of 2 channels each. e.g 1,2 3,4 5,6
- each odd number starting from left to right is the main charging bay in dual cell charging scenarios.
- placing a cell in each of the channel 1 and 2, will cause the majority of the power to go to cell one while a pulsing charge is going to cell 2. This will alternate between the two cells so they come up evenly. The latter is important for folks who still to this day stack batteries
- If you want a more rapid charging of two individual cells, use them in two different bays e.g channel 1 and 3
Wrt ICR and IMR batteries, all Lithium batteries are dangerous period, one is in no way safer than the other, by any stretch regardless what has been said here or elsewhere. I'll get back to this...
In the day, before IMRs hit the market, there were protected and non protected Li Ion batteries. The use of unprotected battery is/was a no brainer, you didn't.
The delta between Li Ion (ICR) and Li Mn (lithium manganese) or IMR is Ln Mn is a safer chemistry, but still a wolf in sheep's clothing, they have gone ballistic. The will both burst if subject to over current but the later will vent without FLAMES.
The safest battery to use is indeed a protected battery, if used for its intended purposes. It has a protection circuit. That being said, I would never purchase batteries of flea bay. Always purchase your batteries from a reputable dealer. If you stumble upon AW batteries or any other brand name batteries at a fraction of the cost BEWARE, good chances they are not the genuine article.
I don't have a dog in this fight. However it gets to be tiresome arguing with customers on safe practices were they respond well I read it on the Forum or FB or whatever. Your cheapest investment is a good charger and batteries followed by a multi meter. The latter is a necessity for those using rebuildables, yet I see folks using their provaris or any other device as an Ohm checker
In closing, right from Provape. The Provari is to be used with AW batteries only, and most definitely not Protected ICRs where the protection circuit of the battery doesn't play well with the protection circuit of the Provari
