Battery isolation

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FFMan
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Battery isolation

Post by FFMan »

Can anyone recommend a manual HV battery isolator, kind of like a service switch ?

I like to be able to isolate the battery, and currently this is done using a modified BMW contactor box, but this consumes 800ma to hold the contactors closed. No economisers here, and that 800ma can run the 12v battery down over time.

thanks
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Bigpie
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Re: Battery isolation

Post by Bigpie »

Don't you have your main contactors open when not driving or charging?
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Ev8
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Re: Battery isolation

Post by Ev8 »

https://citini.com/product/manual-servi ... t-unfused/

I use one of these,

How are you using the bmw contactor box in a way where contacts closed is isolated???
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Re: Battery isolation

Post by FFMan »

Bigpie wrote: Sat Aug 05, 2023 4:35 pm Don't you have your main contactors open when not driving or charging?
Not really as the second stage contactors are open, but the primary ones need to be closed when waiting to charge.

So when i park up at home and plug in the charger with a timed charged to start at say 2am i need to leave the primary contactors closed. This is taking 800ma until it charges and then afterwards. Which is fine if I use it next day, but friday i didn't use the car and the 12v battery ran down. In my install the HV is only connected to the charger when the primary contactors are closed. The secondary contactors connect the inverter but are controlled by the ignition switch.

My primary contactors are in effect manual, there are 3 (-ve, precharge, +ve) small switches controlling the contactors.

I'd like a manual service disconnect.
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Re: Battery isolation

Post by FFMan »

Ev8 wrote: Sat Aug 05, 2023 4:38 pm https://citini.com/product/manual-servi ... t-unfused/

I use one of these,

How are you using the bmw contactor box in a way where contacts closed is isolated???

> How are you using the bmw contactor box in a way where contacts closed is isolated???

i'm not, closed is connected, but it needs to be connected to charge.

yes that the sort of thing. I looked at the datasheet. its not abundantly clear but does this connect/disconnect +ve & -ve i.e. is it 2 pole or single pole ?
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Re: Battery isolation

Post by Ev8 »

Ok, but your using the outlander charger dc-dc like me so just enable the dc-dc whilst charging…

Edit: just read about your timed charging, you may have to come up with timed charging from the car end, so the car closes the contactors and enables charging
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Re: Battery isolation

Post by Ev8 »

Manual service disconnect is usually placed mid pack, it’s only single pole, you just fit it inline between modules
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Re: Battery isolation

Post by FFMan »

Ev8 wrote: Sat Aug 05, 2023 6:42 pm Ok, but your using the outlander charger dc-dc like me so just enable the dc-dc whilst charging…

Edit: just read about your timed charging, you may have to come up with timed charging from the car end, so the car closes the contactors and enables charging
yes i'm thinking my charge ardino could close the contactors when it needs to.
E46 touring
Phev rear motor, OEM inverter cabin heater and charger
BMW 9kwh & 12kwh packs
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