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[flynnstig82r]

My 2017 SR is still under battery warranty until next April so I want to avoid charging above 1C, but I would like to get as close as possible to minimize charging stop time. My bike has the 1.3 kW OBC and 2.5 kW charge tank installed, and I am also looking to add 2 x 3.3 kW TC HK-J chargers via the accessory port.

I believe the pack capacity is 104 aH, so 1C would be 104A. I recall that each HK-J provides 32A, so it should stay under the limit as long as the OBC and CT together do not exceed 40A, which I don’t believe they do. Is this calculation correct, or would I exceed 1C charging with this setup? My pack is currently sitting very close to 20% degradation and may be eligible for a replacement before the warranty expires if I don’t do anything to disqualify it, so I definitely don’t want to go over 1C.

If it might exceed the 1C value, I’ll buy a CAN-enabled HK-J so the power can be limited, unless there is a better method?

[DerKrawallkeks]

Hey,
you don't even have to look at the current, just look at the total power in kW. If you have a 13kWh size battery, 13kW is exactly 1C.
1.3+2.5+3.3+3.3kW = 10.4kW. So you're definitly safely below 1C:)

About the arrangement with OBC, charte tank and external charger others may be able to comment.

If you want to control the power, you need the CAN enabled version, there's no other way. It's pretty simple though, I can give you the code and instructions so you can use an ESP32 to set the power that you want.

[shayan]

My 2017 SR is still under battery warranty until next April so I want to avoid charging above 1C, but I would like to get as close as possible to minimize charging stop time. My bike has the 1.3 kW OBC and 2.5 kW charge tank installed, and I am also looking to add 2 x 3.3 kW TC HK-J chargers via the accessory port.

I believe the pack capacity is 104 aH, so 1C would be 104A. I recall that each HK-J provides 32A, so it should stay under the limit as long as the OBC and CT together do not exceed 40A, which I don’t believe they do. Is this calculation correct, or would I exceed 1C charging with this setup? My pack is currently sitting very close to 20% degradation and may be eligible for a replacement before the warranty expires if I don’t do anything to disqualify it, so I definitely don’t want to go over 1C.

If it might exceed the 1C value, I’ll buy a CAN-enabled HK-J so the power can be limited, unless there is a better method?

Yes you have to look at the total output current from the chargers and that should be below 104A for ZF13.0. 57A (CT) + 13A (OBC)n+ 32A (HKJ) = 102A and that's just below 1C. You should make sure that the HKJ does not go more than 32A

[DerKrawallkeks]

Why is the current relevant? All these chargers provide a constant current, equivalent to their claimed power divided by 116V (nearly full battery).

Also flynnstig82r mentioned that he has a 2.5kW charge tank, which is the old version that was used until 2017.

So I'll stick with my point;) you're way below 1C, no worries. The HK-J can only provide max 32A and not more, not even by mistake, so don't worry there.

[flynnstig82r]

I was asking about 2 x HK-J's + 1 OBC + 1 2.5 kW CT. That seems to be very close to the limit, if not over it.

Also, while we're on the subject, I keep hearing that Zero's don't charge over 1C unless you override some kind of limiter, but I haven't been able to find specifics on how that works. Does it just completely shut down all charging like a circuit breaker?

[MVetter]

Hey,
you don't even have to look at the current, just look at the total power in kW. If you have a 13kWh size battery, 13kW is exactly 1C.

It most certainly is not, because the battery is not 13kWh. OP is right, 104 Amps is the most he can deliver which is, incidentally, well under 13kWh. And that figure will vary based on SoC. 104 amps at empty-ish (95vdc) is 9.8kW, but at 80% (110vdc) is 11.4kW.

kW fluctuates. Amps do not.

I was asking about 2 x HK-J's + 1 OBC + 1 2.5 kW CT. That seems to be very close to the limit, if not over it.

Also, while we're on the subject, I keep hearing that Zero's don't charge over 1C unless you override some kind of limiter, but I haven't been able to find specifics on how that works. Does it just completely shut down all charging like a circuit breaker?

The BMS will open the contactor and the MBB will get mad and make the screen flash.

[DerKrawallkeks]

Well true, I meant 13kW worth of claimed charger power is the same as current, simply cause they are almost all constant current chargers

[MVetter]

Yes but if you try to dump 13kW of power into the battery it will disengage.

[DerKrawallkeks]

Yes but with 10.4kW worth of charger power he's fine.
10.4kW/116V=90A. 104A allowed:)

[flynnstig82r]

Thanks for confirming and letting me know the effects of exceeding the limit. Since I’ll be so close to the limit, I think I’ll make sure to get the CAN-enabled charger. That will also allow me to bring one charger and dial it back to take full use of a single J-station when combined with the CT and OBC.

[victor6.7y]

Hey all,

Is it not important to look at the current? Since you do not want to go over 40 Amps trough the accessory port? (not sure if it is 40, I was guessing 40 cuz that is about 4 Delta Q chargers.)

[flynnstig82r]

Only the 2 x Elcon chargers use the accessory port, so that's 32A.

[MVetter]

Only the 2 x Elcon chargers use the accessory port, so that's 32A.

Everything that goes through the wiring charging harness goes to the same charge fuse. Only way to avoid that is to go directly into the controller via the lugs. Having never used a Charge Tank I don't know how it attaches to the bike but I assume it does the controller.

Each TC unit does 32 amps, so that's 64 + ~13ish from the onboard? = 77ish amps. Still probably within the realm of safety but keep in mind the 100 amp charge fuse is thermal based and somewhat heavily insulated.

[flynnstig82r]

OK good to know, thanks Morgan!