Lockdown Build - Wales

Hi.

I’m so sorry for your loss. But, it could have been much worse. Could have easily burnt your house down. :sob::crossed_fingers:

It sounds like it was the BMS to me. I have had several BMSs malfunction on me. Mine didn’t catch fire but, the PCB board looked melted and burnt a couple times. Twice on a Onewheel, one on a electric skateboard. Since then I have removed all my BMSs. I balance charge externally with a hobby charger, and monitor individual cell voltage during use.

Besides burning your house down, BMSs are just one more thing to fail. I had to walk home more then once due to a failed BMS. I don’t want to have to swim back to shore because of a BMS on an e-foil.

Thank you for sharing this experience. We all need to take this as a lesson learned. Everyone needs to think safety about how you charge and store your batteries. They need to be in a fireproof enclosure whenever they are unsupervised.

I recommend building these batteries with individual cell fusing. Fuse the battery wires, and fuse the balance wires. That’s how I built mine but I still take the fireproof box precautions.

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Samsung 30q cells do thermally runaway.

My battery is 196 of these cells. That’s a huge fire.

It’s not about coming loose. When you wrap the nickel over the edge like you have, there stands a chance than the with time it might chafe against the cell insulation. If its welded on the positive, it will mean it chafes onto the negative and then shorts.
But if another here has had a BMS fails there’s a good chance it could be that too. None of my batteries have the BMS on them. I only connect a BMS when the battery charges and then I run a “dumb” battery. Less chance of failure while doing nothing…

@Flightjunkie I’m sure you have told this already, but how do you charge your 7S14P setup (one bank/site) with an iCharger that can only do 6S Lipo / Lilo / Life max.

Ahh I see what you mean. Well that rules that out also as the nickel was only bent over around 5mm and didn’t go past the cell holder.

I think the BMS is the culprit, I never considered using one externally for charging.

The answer is here:


The X6 has a big brother: the iCharger X8 - 8s 1100W output - for 130usd. Twice as much as the iSDT Q8, 8s too but 500W output only for 60usd .

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I see. I thought that they were the X6 models. My mistake.
I still need to find an easy way to charge / balance my 12S12P build.

Get the icharger and a server power supply

:call_me_hand:

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Thank you for the info.
Till now all server PSU’s I’ve found do not go above 48 volts
As it’s for a 12P it needs more voltage…
What PSU are you using? HP? Dell? ???

Hi.

Sorry. I don’t understand your question.

The power supply just powers the charger. The charger provides the correct voltage and current to the battery.

Most chargers can run off of a range of voltage. The icharger is happy on a 12v power supply as long as you understand the relationship between voltage, amps, and watts. If you are maxing out your charger watts and want to charge your battery at more amps then you need to increase the power supply voltage. Does that make sense?

:call_me_hand:

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My error… I was thinking total pack voltage (the max voltage of all the cells together in series).
Thinking of it now, all a load balancing charger (like the icharger) needs to give the cell voltage.
(For Li ion 4.2 volts).
Amps and Watts are a totally different story :slight_smile:

Thank you for reminding me @Flightjunkie

This is scary! I also have the same BMS. Should I replace it with something else…What would be a more reliable alternative (if I still want to use a BMS)?

I can’t imagine they all self destruct but for piece of mind and for the sake of $50 that they cost, I would mate.

You can always move the BMS outside the battery case, and only use it when charging the cells.

An interesting option.

Would this be more reliable? Is 100A peak current enough for 65151?
100A seems to call for extra cooling. A water cooled aluminium plate?
https://www.energusps.com/shop/product/tiny-bms-s516-150a-750a-36?category=4

But why using a BMS for charging when a Charger Like ISDT can do that?

Cause he already has a BMS and power supply?
All that needs to be done is move the BMS outside the case and get a connector.
After this it can be “safely” charged inside a BBQ :slight_smile:

For me, I opted for BMS because of the simplicity and cleanliness. One battery with one charger with one cable to plug in that’s easy to carry around on the go, Simple’s.

I didn’t want my battery/charger to be all DIY with 2x chargers 2x balance leads a load of cables and power supplies. I had this with my E skateboard. Each to their own but that would just P me off.

Plus cost, the price of 2 balance chargers / power supplies compared to a BMS and a one 18A - 52.8v charger theres not much in it.

Despite whats happened I may still put a BMS in my next build, or have it externally. Just not that last P O S.

Does anyone know what BMS Lift and Fliteboard use, I imagine it’s something custom but would be good to know.