I bought an ISASCALE Contactor Box - Now what?
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I bought an ISASCALE Contactor Box - Now what?
from the guy who brought you:
I bought a BMW 530e hybrid battery pack - Now What?
I bought a BMW 330e hybrid battery pack - Now What?
comes this electrifying sequel, asking more questions than providing answers, in hopes of advancing EV conversionability
ISASCALE Current Sensor and 3 Gigavac Contactors
gonna provide some screen shots of the original listing in case it sells out and the linky link ends up being orphaned
I bought a BMW 530e hybrid battery pack - Now What?
I bought a BMW 330e hybrid battery pack - Now What?
comes this electrifying sequel, asking more questions than providing answers, in hopes of advancing EV conversionability
ISASCALE Current Sensor and 3 Gigavac Contactors
gonna provide some screen shots of the original listing in case it sells out and the linky link ends up being orphaned
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
- Gregski
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Re: I bought an ISASCALE Contactor Box - Now what?
original pictures from the listing
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
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Re: I bought an ISASCALE Contactor Box - Now what?
contactor information
This contactor has a 12V coil. It will latch at 8V and accept up to 16V. The maximum continuous current the contactor can handle depends on the wire used. If you use 2/0 it will handle 350A, and if you use 4/0 it will handle 400A. Peak current is closer to 1000A for 30 seconds, and even higher for shorter durations. This is a common contactor with plenty of uses.
- 2 X Gigavac GV200BAB-1 $164 each
- 1 Gigavac P125BDA $87
This contactor has a 12V coil. It will latch at 8V and accept up to 16V. The maximum continuous current the contactor can handle depends on the wire used. If you use 2/0 it will handle 350A, and if you use 4/0 it will handle 400A. Peak current is closer to 1000A for 30 seconds, and even higher for shorter durations. This is a common contactor with plenty of uses.
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
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Re: I bought an ISASCALE Contactor Box - Now what?
Isabellenhuette IVT-S-1K-U3-I-CAN2-12/24 $372
One of the fanciest current sensors we have ever seen. This sensor does more than just measure current up to 1000A, it also has 3 voltage sensors built in. You can measure overall pack voltage or voltage drop over contactors during operation for a health assessment. This current sensor communicates by CAN Bus.
One of the fanciest current sensors we have ever seen. This sensor does more than just measure current up to 1000A, it also has 3 voltage sensors built in. You can measure overall pack voltage or voltage drop over contactors during operation for a health assessment. This current sensor communicates by CAN Bus.
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
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Re: I bought an ISASCALE Contactor Box - Now what?
Gigavac P125BDA, Ohmite AZ101KE 100 OHMS, and 3A Fuse
This unit is by far the handiest. This professionally designed and soldered board includes a precharge contactor, fuse, and resistor. If you want your contactors to last a long time, you need to precharge the capacitors in your equipment. Apply 12V to the low voltage side and the contactor closes with the resistor in circuit. The fuse rating is 3A on the high voltage side.
This unit is by far the handiest. This professionally designed and soldered board includes a precharge contactor, fuse, and resistor. If you want your contactors to last a long time, you need to precharge the capacitors in your equipment. Apply 12V to the low voltage side and the contactor closes with the resistor in circuit. The fuse rating is 3A on the high voltage side.
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
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Re: I bought an ISASCALE Contactor Box - Now what?
QUESTIONS SECTION:
So what is it, and why do I need it?
How did I find out about it, and why should you care?
What is an ISA and do I really need one?
Are these economizer contactors?
Has this red circuit board been reversed engineered already?
So what is it, and why do I need it?
How did I find out about it, and why should you care?
What is an ISA and do I really need one?
Are these economizer contactors?
Has this red circuit board been reversed engineered already?
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
Re: I bought an ISASCALE Contactor Box - Now what?
Interesting & handy detail on the two big Gigavac GV200BAB-1 contactors:
They are the dual coil version. This means that while they do not have an economizer, they automatically will — after initial closing (aka “pick-up”) current (3.9A for 0.75 sec) — release one of the two coils to make the continuous 12v current draw on them drop to around 0.23A only.
Spec sheet attached.
They are the dual coil version. This means that while they do not have an economizer, they automatically will — after initial closing (aka “pick-up”) current (3.9A for 0.75 sec) — release one of the two coils to make the continuous 12v current draw on them drop to around 0.23A only.
Spec sheet attached.
- Attachments
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sensata_gigavac_gv200_series_open_contactors_datas-3074934.pdf
- (821.9 KiB) Downloaded 356 times
Plan to build someday soon<TM>:
VW T3 Bus
Leaf Motor Stack incl Transaxle
Brat Industries VW Driveshaft Adapters
Model 3 55kwh Battery / MEB 58kwh Battery
Foccci CCS
Zombieverter VCU
VW T3 Bus
Leaf Motor Stack incl Transaxle
Brat Industries VW Driveshaft Adapters
Model 3 55kwh Battery / MEB 58kwh Battery
Foccci CCS
Zombieverter VCU
Re: I bought an ISASCALE Contactor Box - Now what?
is that board its own thing though? i assumed it had some control smarts that would need to be reverse engineered, if it's a complete all in one precharge contactor package with no reverse engineering needed thats extremely niceGregski wrote: ↑Tue Nov 26, 2024 6:21 pm Gigavac P125BDA, Ohmite AZ101KE 100 OHMS, and 3A Fuse
This unit is by far the handiest. This professionally designed and soldered board includes a precharge contactor, fuse, and resistor. If you want your contactors to last a long time, you need to precharge the capacitors in your equipment. Apply 12V to the low voltage side and the contactor closes with the resistor in circuit. The fuse rating is 3A on the high voltage side.
8S7A7157-scaled.jpg
DSC_2259-scaled.jpg
Re: I bought an ISASCALE Contactor Box - Now what?
also dont forget the box has two of these amphenol powerlok connectors you can just unscrew from the front
Re: I bought an ISASCALE Contactor Box - Now what?
Well, since the layout and components used seem great no matter what, I intend to re-use the box (or just the layout and bits) even without the control board - with a fair bit of re-wiring…
But I also would like to take a closer look at the board, just out of curiosity. Do I know what I’m doing there? Definitely not!

Plan to build someday soon<TM>:
VW T3 Bus
Leaf Motor Stack incl Transaxle
Brat Industries VW Driveshaft Adapters
Model 3 55kwh Battery / MEB 58kwh Battery
Foccci CCS
Zombieverter VCU
VW T3 Bus
Leaf Motor Stack incl Transaxle
Brat Industries VW Driveshaft Adapters
Model 3 55kwh Battery / MEB 58kwh Battery
Foccci CCS
Zombieverter VCU
- Gregski
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Re: I bought an ISASCALE Contactor Box - Now what?
putting your money where your mouth is...
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
Re: I bought an ISASCALE Contactor Box - Now what?
Very intertesting offer.
I contacted the shop about delivery to germany but sadly didn't get any response...
I'd love to order the kit as most of it can be used without any problems i guess. The custom PCB is interesting but is it needed when using a VCU anyways? I don't think so.
I contacted the shop about delivery to germany but sadly didn't get any response...
I'd love to order the kit as most of it can be used without any problems i guess. The custom PCB is interesting but is it needed when using a VCU anyways? I don't think so.
Re: I bought an ISASCALE Contactor Box - Now what?
I am in Austria and used a forwarding service to get them to send it here … forward2me
I ..err.. cheated slightly, as i put in the us shipping address i got from the service also as billing address on greentec auto (required a us address).
Went down without an issue. Price went up, of course, with shipping & customs -> still worth it IMO for the components alone, and in such a neat package & layout
I ..err.. cheated slightly, as i put in the us shipping address i got from the service also as billing address on greentec auto (required a us address).
Went down without an issue. Price went up, of course, with shipping & customs -> still worth it IMO for the components alone, and in such a neat package & layout

Plan to build someday soon<TM>:
VW T3 Bus
Leaf Motor Stack incl Transaxle
Brat Industries VW Driveshaft Adapters
Model 3 55kwh Battery / MEB 58kwh Battery
Foccci CCS
Zombieverter VCU
VW T3 Bus
Leaf Motor Stack incl Transaxle
Brat Industries VW Driveshaft Adapters
Model 3 55kwh Battery / MEB 58kwh Battery
Foccci CCS
Zombieverter VCU
Re: I bought an ISASCALE Contactor Box - Now what?
That is a very good idea!Landsi wrote: ↑Sat Dec 21, 2024 6:47 pm I am in Austria and used a forwarding service to get them to send it here … forward2me
I ..err.. cheated slightly, as i put in the us shipping address i got from the service also as billing address on greentec auto (required a us address).
Went down without an issue. Price went up, of course, with shipping & customs -> still worth it IMO for the components alone, and in such a neat package & layout![]()
Did not think about that before ... maybe I'll give it a try.
Or even better: is anyone from this forum interested in "intercontinental" help for similar minded tinkerers from abroad?

Would anyone else from the DACHI region be interested?
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Re: I bought an ISASCALE Contactor Box - Now what?
Did the box came with a lid cover? I am intrigued by the vertical HV connections.
- Gregski
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Re: I bought an ISASCALE Contactor Box - Now what?
no word on the street is that it was bolted up to the battery pack directly so that lid of the battery pack was it's lid cover, someone please correct me if I'm wrongChurchMcTruck wrote: ↑Wed Feb 05, 2025 9:06 pm Did the box came with a lid cover? I am intrigued by the vertical HV connections.
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg