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[Doctorbass]

This morning i am a little worried about the  heat that the 1.3kW transfer to the battery pack.

I toutched the top of the ZF13 and it was warm.. after 6 hours of 1.3kW cahrge. there is still 6 other hours to go. The ambient is 23 degree C in the garage btw.

but when i toutched to teh bottom of the ZF13, near the acces close to teh motor, it was very warm! I measured 47 degree C witch is certainly not helping the cell life!!

I would like to get your opinion about that. I work with lithium since years and it is one of the  basic rule that lithium cells dont like heat!

I worrie for two things: cell balance and life  over the entire life of the battery  as heat is not spread with perfect uniformity over the  bottom of the battery so some cells get more heat than others,

The fact that i have a powertank  on teh top that dont receive that heat so this one will not have the same conditions and the internal resisatcne of it will be different.

The previous DELTA Q charger had fins witch transfered heat to the air and less to the battery .. now with these new poted chargers that are directly transfering heat to the battery taht is making me to worrie a bit....

our weather is less warm than in California.. so i can imagine a battery being left at ambient of 30 or 35Celsius would have a derating of  10 more degree!! 57 celsius on teh bottom of the battery is not what i call GOOD for the cell life!...

The battery itself is perfectly engineered but the decision to have the charger to transfer heat to it is questionable.

What are your opinion?

Doc

[Cama]

I guess we should find a way to cool the battery while charging. But in order to take the uprising heat from the onboadcharger just dont use it? Maybe only for the toploading for balancing?

Since fast charging is very nice and I saw the temperature rising from 23-25 °C to 35 °C while charging from 40 to 89 % SoC with 8 kW (max 8500 Watt), how can we cool the battery while charging?

I asked Farasis about the ideal batttemp for calendar-life.

They answered:

The best way to achieve the longest calendar life is to store the battery at 30C or lower, preferably lower, (15-25C).  Also having the battery stored at ~80% SOC is best.   Just make sure the battery does not over discharge if stored for a long time (months).

[Richard230]

Would it be possible to hook up a fan and duct to blow some of the heat out of the chassis when the bike is being charged?  It seems to work for my Sears 19.2 volt tool lithium battery charger. 

[Doctorbass]

You are right Cama and the information from Farfle of Farasis is very usefull and is about what i expected.

However this raise also a very good question: If we forget about the heat effect, Is fast caharging really more dammagable to a lithium battery compare to slow charging.

I started a thread about that question here: http://electricmotorcycleforum.com/boards/index.php?topic=7090.0

[Doctorbass]

Would it be possible to hook up a fan and duct to blow some of the heat out of the chassis when the bike is being charged?  It seems to work for my Sears 19.2 volt tool lithium battery charger. 

That is exactly what i tought this morning.. i was looking at the battery "pan" inder the bike and looking for some area to pua a blower that woudl not be too much affected by the road debri/dust. etc...

Doc

[hubert]

DrBass, regarding your worries about temperature gradient throughout the pack, there is a way to assess it more precisely.

If you connect to the OBD2 connector with a serial link (RS232 with TTL level) and a terminal (PC plus teraterm or putty or so), you will be able to access in realtime all the temperature sensors. As far as I remember, there are 8 battery sensors, 2 per block. In your case there should be 10 sensors.

This way you can see during charging how far the temperatures increase, and if there is a noticeable difference between the blocks, due to the charger's dissipation.

[Doctorbass]

DrBass, regarding your worries about temperature gradient throughout the pack, there is a way to assess it more precisely.

If you connect to the OBD2 connector with a serial link (RS232 with TTL level) and a terminal (PC plus teraterm or putty or so), you will be able to access in realtime all the temperature sensors. As far as I remember, there are 8 battery sensors, 2 per block. In your case there should be 10 sensors.

This way you can see during charging how far the temperatures increase, and if there is a noticeable difference between the blocks, due to the charger's dissipation.

You are right Hubert. I am familar with the  Zero diagnostic comm. I own the Zero diagnostic tool already.. i'll check for that tomorrow it,s a great idea.

Doc

[KrazyEd]

   I have noticed similar heat concerns on my 2016 SR and on board charger. Very hot to the touch at both ends. I have a J1772 Adapter that has three one foot or so C13 ends. When Plugged into Level 2 J1772 the voltage
is 220v. ( 208 where I tested ). The cables and ends are no more than warm to the touch not much more than ambient temperature. Are you charging at 110 or 220? I know that there is more resistance and therefore more
heat with longer cable, but, ( I think ) that going with 220~240 over 120 would cause less heat at the same  draw. I have read where people have observed ( perceived? ) marginally faster charging when using the higher voltage.
I have a fairly long ( for a Y ) Y cable with C13 ends in and out. Will try to remember to take with me and check the difference.
   As far as a fan and cooling goes, that wouldn't hurt. I purchased a couple 12" automotive radiator fans for an experiment that didn't work. Was sitting here one day trying to think of putting them to work. Just for grins, I plugged
one into a cheap harbor freight solar kit. Worked fine mild breeze with one 15 watt panel, fairly nice with 3. These produce an output of 19~21 volts with no load, probably dropping to below 12 once fan is connected. Same fan connected
to standard 12 volt battery and breeze was much stronger. Given what I imagine you have access to around your compound I have to believe that you should be able to cobble something together for both of these scenarios.
It is 110 degrees Fahrenheit  Here in Vegas right now so any heat reduction would be beneficial.