Will new Video over current protection

[PeSCaLo]

Hi Guys

Let’s talk about Will’s new Video over current protection. Video

that bench test it’s great.
Where can we find those resistors?

@Will Prowse

 

[Will Prowse]

1000 Watt Dump Load Resistor | Blemished

1000 Watt dump load resistor available in 12 volts. Heavy duty vented standoffs for air flow. Perfect divert dump load for wind turbines and solar panels.

windandsolar.com

Really fun test. Nice to hook up any battery in seconds and see what it's actually capable of.

I need to add some smaller resistors to fine tune the consumption to 100A increments

 

[Partimewages]

That's 3410 btu's! Nice supplementary heat. If you have winter time extra. If not mount it outside

 

[Luk88]

Kudos for actually doing it(although the focus was overcurrent protection not DC IR). I think no battery testing is complete without trying to pull serious current (1C or whatever the max rating is) and comparing actual voltage drop to the spec.

Doing that is a pretty reliable method to determine battery state of health. I hope this resistor array will be used in future videos too.

 

[robbob2112]

Ya know, my general feeling on the subject is that all batteries that don't already include built in fuses or breakers should have a fuse added. If paralleling 2 then a MRBF on the post and preferably a class T to the inverter.

If paralleling 3 or more a class T is better - the more in parallel the more it becomes required.

And if 3 batteries in parallel and they do not have a fuse/inverter built in and the cable is more than about a foot long it ought to have a class T at the bus bar end to prevent excess current in the cable.

Just my 2 cents.

 

[SomethingAppropriate]

winter time extra

Never heard of such things.

 

[robbob2112]

So, here is a thought @Will Prowse - when you redo it add some additional switches and wiring do you can do series as well as parallel. With that you could control exact amount of amps verse doing only in steps. Configure for common maxes - 100amps, 200amps, etc.

Just a thought and a way for me to spend your time and money

 

[mikefitz]

I would be interested to see a short across the battery, the resulting peak current and BMS response time. This is a more realistic test of a system fault rather than a gradual increase of load on the battery. The test setup may need more than safety glasses!

 

[robbob2112]

I have it - contactors to engage the different resistors and a 10 position switch - so you can dial-a-resistance and to spend more of your money - buy 20 more of them - so 3 layers tall - contactors so you can turn on whatever sequence it takes to hit a particular resistance/amps Shouldn't damage them if you set things while the test battery is being disconnected - The $15 contactors should work for it

TE Connectivity EV200AAANA 500a 0-900vdc Tyco 12/24v

These were recovered from EV battery modules. These are VERY EXPENSIVE online. If you have any project that needs a high current relay this is your chance to save some money. Make a cheap 30a BMS into a 500a BMS. This will work for batteries in the 9-36v range so perfect for Lifepo4 and Lithium...

batteryhookup.com

OK, I am a little out there are carried away, I admit it.

 

[HRTKD]

Sweet video. The NOCO batteries caught my eye. I need a small battery to start my on-board RV generator, but I don't want a flooded lead acid battery because of the weight and maintenance. However, the FLA battery works even at low temperatures for both charge and discharge.

Even if I went with the biggest NOCO battery, it's still only 5 pounds! I've been looking for a way to lose some weight off of the tongue.

Here's the DataSheet if you're interested. Note that NOCO says the battery can be charged down to 14°F. I'm tempted to install one without any warming pads, just to see what happens.

I would like to see one of the new JK Inverter BMS go through the same test.

 

[HRTKD]

I would be interested to see a short across the battery, the resulting peak current and BMS response time. This is a more realistic test of a system fault rather than a gradual increase of load on the battery. The test setup may need more than safety glasses!

As I recall, there's a guy on the forum that has already done something like that, but for fuses. It wouldn't be much of a change in his test equipment to do it for BMS.

 

[robbob2112]

Will did overcurrent tests in his latest videos. There is another guy shilling battle born batteries that did dead short tests.. most BMS clicked right off with no damage... his testing methodology for comparing batteries left a LOT to be desired... but he did short batteries.

 

[HRTKD]

Will did overcurrent tests in his latest videos. There is another guy shilling battle born batteries that did dead short tests.. most BMS clicked right off with no damage... his testing methodology for comparing batteries left a LOT to be desired... but he did short batteries.

Pretty sure we're thinking of different people. The guy that was testing fuses was using Victron LiFePO4 batteries (as I recall) without the BMS, so there was no shutdown on the part of the battery.