Battery isolation switch

Recently there have been a few battery deaths due to controllers being left on. I like to use Justins controllers because they state no current draw when switched off, i have used these before and left them connected but turned off with no problems, which is all well and good but what if I forget or a fault develops, my newly built 20s 20ah pack needs some protection. I have been looking for a 50a 80v dc trip which could act as a fuse and also an isolator switch for the pack.
While looking I saw loads of 48v trips etc and was wondering if they would stretch to 84v? Well I saw this video and it brought home how important getting the correct rating is!!
I presume in higher voltage breakers the contacts have a greater physical separation distance and much greater in DC than AC.

https://www.youtube.com/watch?v=Zez2r1RPpWY

Sorry, I don't know how to embed it!!

So I still have not found a suitable breaker in the uk, the all seem to be over there in the states!!

Has anyone ever made one that could monitor voltage and trip at lvc? as a last line of defence.

I use a Blue Seas 7630 50A 65vdc breaker at 73V - works quite well - actually tripped and tested. This is a marine breaker you should be able to get - or an equivalent from another manufacturer. This has an interrupt rating of 7500A - so - no self-destruct issues. I have this 50A unit in series with two other 50A Maxifuses in the batteries, but after a few shorted controller incidents, the breaker tripped every time, but the fuses never blew...

You can also use a solar breaker, a better high voltage choice - here's a unit by Midnite Solar - 150vDC at up to 100A. This is looks like an ideal ebike solution.

I actually ended up running the bike hotter than planned and the 50A unit is too small. I need to jump to the solar breaker, but the mounting needs to be reworked. Anyhow - I selected too low - select a breaker at least 150% of your expected max - it's there for short protection so Big Current will certainly happen...

Anyhow - all in the States, but specific searches for marine and solar parts might turn up equivalent parts on your side of The Pond.

They look great. I think it would be best to buy from the USA though as there seems little available in the UK. The best I could find were these:

http://www.ecs-marine-equipment.co.uk/marine-equipment/c-series-circuit-breaker-handle-actuator-visi-rocker-item-26980.html

Only 63V max (I suspect designed for 12V...)

I'm using a 63A domestic circuit breaker as a switch. It's designed for 240 volts AC, I'm using it for 33 volts DC. I also have a 40 amp fuse in line with that.

I have a 220 ohm resistor across the switch, so that the controller can charge up slowly, instead of there being a big spark when I plug this in to the battery.

Posting just so I can find it again.

cassschr1 said:

Posting just so I can find it again.

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