Engine fans running when charging.... normal?

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goi
Posts: 82
Joined: Thu Aug 27, 2020 1:49 pm

Post by goi »

lfpcorreia wrote: Wed Sep 30, 2020 11:33 pm As such there's a question I'd like to ask: Should we charge our batteries every day? or should we let them get low/depleted before charging again?

For example, let's say I make 10km every day. Given the 40km estimated range with a full battery charge, should I charge everyday or continue to drive until the battery capacity drops below a certain percentage?

What's better for the battery on the long run?
First the easy answer: It doesn't matter, because modern Lithium-Cobalt-Cells don't have any memory effect. If you deplete the battery each day by 25% and load it immediately (not fast loading, but normal loading), it counts every 4 rounds as a full cycle.

Next the complex answer: It depends on the SOC you left the car with - As the last 15-20% takes significant longer to load and it wears off the battery more than a SOC 20 to 80 charge, there are some precautions about that:
- Don't let the battery deplete to low (SOC <10)
- Try to avoid loading the battery over SOC >90

1. Volvo itself has build in some limits by not using the full technical SOC of the battery pack.
2. Volvo/LG chem/CATL has build in some protection for low states
3. Volvo has programed the charger that it will only load to a certain amount but never to SOC 100! Nevertheless to the driver it will be shown as 100% and not as SOC 90.

Having these constraints the above easy answer should match for most of the people.

BUT:
- When your battery is nearby fully depleted you shouldn't park with a low SOC for a long time (weeks/months). In this case, try to load the battery to at least 40%.
- When your battery was nearby fully depleted and you put it on a charger, let it load at least to 40% or higher
- If your daily electric range is well within limits, try not to load over 90% - but the internal SOC might be anyhow internally limited as I cannot say if that measure would help prolonging the lifetime of the battery.

BATTERY LIFETIME:
- given a cycle from SOC 10-90, the battery life is usually calculated within 5000 cycles+ - which gives you, if you do full cycle every day of the year, over 13 years.
- Due to chemical processes a battery cell might age over the time even without doing too much cycles. As an idea, it is said in several literatures, that the battery will degrade recognisable within 10 years. The best battery guarantee you can find are 1.000.000 km/800.000 miles and 10 years for the battery.
- Though by normal use (ie. 2 cyles per business day 1 cycle on weekends), you'll find yourself at 9 years+
- If you do only SOC 20-80 it goes up to 8000+ and more cycles, but than the ageing by the years will kick in.

My expectations are, that I am going to exchange the battery (which I expect to be <<5000 €) no more than every 10-12 years.
since 2023: XC40 Pure Electric Twin Motor Ultimate MY24
since 2020: Mirai II Fuel Cell, MY21
2020-2023 XC40 Recharge Inscription (Pro) T5 (132+60 kW), MY21 late

lfpcorreia
Posts: 99
Joined: Thu Aug 01, 2019 11:53 am

Post by lfpcorreia »

Thank you so much goi.

Best clear explanation I’ve found in the whole internet.


I’m a developer, PM me if I can help you anytime!
T5 Twin-engine Momentum Plus
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