RodHam
Posts: 26
Joined: Wed Dec 16, 2015 7:50 am
Location: Montreal Quebec

Re: Battery Temperature, isn't 20c the sweet spot?

Tue Jan 05, 2016 1:01 pm

I was just on the OpenEVSE forum and it looks like the temp gauge on the app is showing the evse temps which coincidently match the battery's temp the few time I've compared it. So I will only use the service menu battery temp in the future.

Edit: Next Day (Jan 06, 7:29AM)
This morning outdoor temperatures were -9.5c and battery temp +11c and App showed the Evse at +4c
Rodney
2015 i3 BEV Lodge with winter tire kit. Juicebox Pro 40a EVSE
2005 Honda S2000
1976 GMC Palm Beach motorhome

janner
Posts: 235
Joined: Sun Jan 25, 2015 5:24 am
Location: Bath, UK

Re: Battery Temperature, isn't 20c the sweet spot?

Thu Jan 07, 2016 8:59 am

Rodham - another very interesting post, thank you for the graphs.

It may help increase battery temperature if you timed the charge to finish just before preconditioning started - you would then have the residual warmth from the battery charge as a start point for the pre-con. Precon heater is only 1kW and the battery pack can't absorb too much heat in one go - as your graphs show it takes energy then lets it dissipate through the pack before taking more energy.

Do you know what the battery temperature was at the end of charging?
2015 i3 ReX Solar Orange, Loft interior world. BMW professional, 19" turbine-spoke 429 wheels, DC rapid charging, driving assistant plus.

janner
Posts: 235
Joined: Sun Jan 25, 2015 5:24 am
Location: Bath, UK

Re: Battery Temperature, isn't 20c the sweet spot?

Thu Jan 07, 2016 9:04 am

Does anyone know what the three blips in Rodham;'s charging graph are? There's one at the end, one about 45 minutes before the end and one about 90 minutes before end.
2015 i3 ReX Solar Orange, Loft interior world. BMW professional, 19" turbine-spoke 429 wheels, DC rapid charging, driving assistant plus.

RodHam
Posts: 26
Joined: Wed Dec 16, 2015 7:50 am
Location: Montreal Quebec

Re: Battery Temperature, isn't 20c the sweet spot?

Fri Jan 08, 2016 2:33 am

I'm going to guess that those blips are the battery thermal management systems kicking in. The curve is usually smooth but this one is from an evening of -22c.
Rodney
2015 i3 BEV Lodge with winter tire kit. Juicebox Pro 40a EVSE
2005 Honda S2000
1976 GMC Palm Beach motorhome

janner
Posts: 235
Joined: Sun Jan 25, 2015 5:24 am
Location: Bath, UK

Re: Battery Temperature, isn't 20c the sweet spot?

Fri Jan 08, 2016 7:56 am

Makes sense. Thanks.
2015 i3 ReX Solar Orange, Loft interior world. BMW professional, 19" turbine-spoke 429 wheels, DC rapid charging, driving assistant plus.

janner
Posts: 235
Joined: Sun Jan 25, 2015 5:24 am
Location: Bath, UK

Re: Battery Temperature, isn't 20c the sweet spot?

Sun Jan 10, 2016 9:50 am

Rodham. Was this precon with the latest November update software?
2015 i3 ReX Solar Orange, Loft interior world. BMW professional, 19" turbine-spoke 429 wheels, DC rapid charging, driving assistant plus.

RodHam
Posts: 26
Joined: Wed Dec 16, 2015 7:50 am
Location: Montreal Quebec

Re: Battery Temperature, isn't 20c the sweet spot?

Mon Jan 11, 2016 11:48 am

janner wrote:Rodham. Was this precon with the latest November update software?
Thought I had the latest, took delivery Dec 6th but it has the march update I001-15-03-502.
Rodney
2015 i3 BEV Lodge with winter tire kit. Juicebox Pro 40a EVSE
2005 Honda S2000
1976 GMC Palm Beach motorhome

i3atl
Posts: 437
Joined: Wed Mar 05, 2014 10:47 pm
Location: Atlanta, GA

Re: Battery Temperature, isn't 20c the sweet spot?

Wed Jan 13, 2016 7:02 am

My November update cars seem to target 10C as well for battery preconditioning.

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