Daly BMS - a potential cause of battery fires?

[guerney]

Years ago, when we used to use Ping LiFePO4 batteries, they had LEDs on the bleed resistors, which lit up when the transistor switched on so you could see which ones were active until all the lights would be on at the end of the charge.

If I found a BMS which had bleed resistor LEDs, I'd certainly cut an oblong window into my battery case to inset a little window, so I could watch the pretty lights.

They vary in size but most are quite large so must be at least 1/2 watt rating.

If they're high efficiency and there's something like about 10 or more of those, that seems like a lot of heat trapped in the small volume of air in a battery case - I did wonder at one stage if I should drill holes into/Swiss cheese my battery case, then line the inside of the case with heat conductive silicone, then cut some discs out of that material to stuff into the 1/2 inch holes from the outside, then cover the lot with a big moulted sheet of aluminium, using that as a heatsink... but I don't think my bleed resitors get hot enough, or get my battery pack hot enough, to justify my doing so.

 

[saneagle]

If I found a BMS which had bleed resistor LEDs, I'd certainly cut an oblong window into my battery case to inset a little window, so I could watch the pretty lights.




If they're high efficiency and there's something like about 10 or more of those, that seems like a lot of heat trapped in the small volume of air in a battery case - I did wonder at one stage if I should drill holes into/Swiss cheese my battery case, then line the inside of the case with heat conductive silicone, then cut some discs out of that material to stuff into the 1/2 inch holes from the outside, then cover the lot with a big moulted sheet of aluminium, using that as a heatsink... but I don't think my bleed resitors get hot enough, or get my battery pack hot enough, to justify my doing so.

Water is far more harmful than a bit of heat. You're panicking about nothing. When the resistors are bleeding, they become warm. You can put your finger on them to feel it. Nothing will burn. If they got hot enough, they'd melt the solder and fall off before anything burned, so self-regulating.

 

[guerney]

After the DALY failed I looked into other BMS and saw the BeMuchSafer ones with no balance but have protection for charge/discharge, I bought in case it was needed an active balancer to wire in but have not yet needed to.

Their 30A BMS with switch and balancing looks very interesting, as I would have access to the full continuous 25A capability of my LG MH1 called battery pack. I could then increase the controller limit to 19A, and have up to 6A available for bike lights, guitar amp, PA system, stage lights, lasers and beer fridge. I can't find any reviews about BeMuchSafer BMSs, there might be user experiences posted somewhere if I search enough.

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