Trickle Charging vs Quick Charging vs Cold Wheather

I have listened a bit on evtv.me and watched their tests.

At least for one cell, I am not sure if that is the famous, made in USA but imported from China and produced in Korea ...

They found what counts is the temperature of the electrodes, not cell temperature, not ambient temperature.

Charging below 0C = 32F is bad. It blocks parts of the electrodes and deteriorates current and capacity permanently. So charging slowly is bad, better get the batteries warm as fast as you can and keep them warm until fully charged. Disconnect before trickle charging begins.

Quick charging is good for the batteries. They charged with 3C. That means fully charging in 3 hours time if I got it correctly. Stop charging when you think it is 80%. It turns out later that the batteries are charged more than 90% at that moment.

Trickle charging and all kinds of slow charging is bad. You are going to overcharge without even noticing. That is what kills the batteries.

We have got some -7C = 19F right now. A rather unexpected winter and rather early for us. I plug in as soon as we come home and get it the full 230V/16 (14A actually) but I unplug as soon as I see charging gets slower. So I give away the final bar mostly. I hear the cooling system working time and again so I am sure it is warm enough for the batteries.

I have not found the Stone of the Wise. Maybe Jack Rickards has but even he says the results were not what they would have expected.

I've read if you charge as soon as you pull in, you'll be fine as the batteries are warm from the drive. We also have a battery warming system when temps reach below -15c, I'm sure the Mitsubishi engineers understand the chemistry otherwise they'll be paying for a lot of warranty claims.

On quick charging, our owners manual warms about doing it too much as it will degrade the batteries.

The cooling noise (girgling sound) you are hearing is coming from the electronics not the batteries, the on-board charger gets quite hot. The fan part is just blowing air through the battery pack if it gets too warm. I usually only hear that shortly after I plug in and then the fan turns off. The girgling liquid sound is the charger cooling.

I'm sure Don will be around to correct me if I'm wrong. :lol:

peterdambier said:

Quick charging is good for the batteries

Trickle charging and all kinds of slow charging is bad. You are going to overcharge without even noticing. That is what kills the batteries.

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You and Jack can do anything you like - I'll continue to recharge at the slowest practical rate. The car only comes with a 120 volt 8 amp 'trickle' charger over here and it doesn't overcharge the batteries, plus our owners manual warns us that quick charging the batteries is NOT good for them and we should employ that mode only when absolutely necessary

I admire Jack and all the great EV research and design he's done over the years, but when it comes down to what's best for MY EV and it's battery pack, I'll be taking my advice directly from Mitsubishi . . . . they are the ones I'll be dealing with when and if I ever have a battery problem

Don

Don, I tend to agree with you. In addition to the heat created just by charging - even level I and II charging - there is the battery warmer. According to this article,

a battery warming system keeps battery temperature above minus 25oC

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http://www.caaquebec.com/DocumentLi...estAttachment/mitsubishi-i-miev-2012-en_0.pdf

So Mitsu apparently has identified that temp as the bottom limit for charging. I'm comfortable that Mitsu has given us the info we need to properly care for the car's battery. While there may be ways to obtain some increase in battery life and its ability to hold its charge, I don't think we're doing anything harmful by following the manual.