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Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 12:50 am
by cwerdna
metricus wrote:The Leaf already has a TMS for the stator and the onboard charger. Beats me why they did not add the battery pack to the circuit. But that's another topic.
They probably have different ideal operating temps.

And, AFAIK, the liquid cooling system for the Leaf motor and OBC isn't connected at all with the AC system and its refrigerant. So, it won't be able to get those bits cooler than outside air temp, which is probably ok.

FWIW, as I posted in the Bolt thread (with video), they have 3 separate "coolant" loops: the loop for the OBC, motor, DC to DC converter and maybe one more thing also isn't cooled by the AC compressor and is just sent to a radiator. The coolant loop for the battery does have its heat removed by the AC compressor system and apparently also has a 2 kW coolant heater. The 3rd loop is for the crap "water" heater and that's not connected to anything else.

And, there can be considerable extra complexity to cool each of the modules properly.

Maybe I'll get to watching the entire 1.5 hour video for the Bolt battery at https://www.youtube.com/watch?v=ssU2mjiNi_Q someday.

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 6:20 am
by SageBrush
cwerdna wrote: And, there can be considerable extra complexity to cool each of the modules properly.
People would appreciate even a half-baked attempt for the LEAF

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 6:31 am
by DaveinOlyWA
cwerdna wrote:
metricus wrote:The Leaf already has a TMS for the stator and the onboard charger. Beats me why they did not add the battery pack to the circuit. But that's another topic.
They probably have different ideal operating temps.
Way different and not very effective. The charger gets quite warm even with L2 charging (it does not heat up during DCFC sessions) so well above "pack prime" temps.

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 6:44 am
by metricus
DaveinOlyWA wrote:
Way different and not very effective. The charger gets quite warm even with L2 charging (it does not heat up during DCFC sessions) so well above "pack prime" temps.
In other words we need a heat pump not just a radiator. Makes sense because at some ambient temps (hi 30C) we already have throttling.

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 8:14 am
by lorenfb
cwerdna wrote: And, there can be considerable extra complexity to cool each of the modules properly.
Thanks for the post. It provides very detailed insight into the overall complexity, e.g. all those hose connections.
Anyone remember having water leaks around coolant hose connections on the old ICEVs or having to replace
a bad hose? Love to hear the labor cost from a GM dealer to replace a bad hose/clamp in the Bolt battery system.

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 8:15 am
by danrjones
At 6 am my battery temps were 92 and 89.4 max and min. That's with no charging. Plan to repeat tonight but with 2 hrs of lvl 2 from 3 to 5am.

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 8:48 am
by metricus
lorenfb wrote:Thanks for the post. It provides very detailed insight into the overall complexity, e.g. all those hose connections.
Anyone remember having water leaks around coolant hose connections on the old ICEVs or having to replace
a bad hose?
LOL, yes I know.... I have a 1988 Ford Ranger which I keep just because I can fix everything on it myself. Rare bird!.

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 9:07 am
by lorenfb
metricus wrote:
lorenfb wrote:Thanks for the post. It provides very detailed insight into the overall complexity, e.g. all those hose connections.
Anyone remember having water leaks around coolant hose connections on the old ICEVs or having to replace
a bad hose?
LOL, yes I know.... I have a 1988 Ford Ranger which I keep just because I can fix everything on it myself. Rare bird!.
Yes, being able to be a DIY type for many ICEV problems can be a repair cost saver. But not so much for a BEV, especially for future
potential cooling problems as depicted in the video. Adding a cooling system does increase the probability of a long term BEV
system failure. Many can remember when Tesla considered swapping batteries to reduce the vehicle's downtime versus charging,
consider that effect on reliability, totally laughable.

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 10:01 am
by smkettner
danrjones wrote:At 6 am my battery temps were 92 and 89.4 max and min. That's with no charging. Plan to repeat tonight but with 2 hrs of lvl 2 from 3 to 5am.
Anyone know the optimum temperature?
Or the normal range for longest life?

Re: 2019 Leaf battery overheating

Posted: Wed Jun 12, 2019 10:51 am
by LeftieBiker
smkettner wrote:
danrjones wrote:At 6 am my battery temps were 92 and 89.4 max and min. That's with no charging. Plan to repeat tonight but with 2 hrs of lvl 2 from 3 to 5am.
Anyone know the optimum temperature?
Or the normal range for longest life?
It probably isn't possible to get the best battery temps for both life and output in normal Summer weather. As low as is possible would have to do. IIRC lithium batteries like temps around 50-70F.