ElectricMotorcycleForum.com
Tech => Tech Help => Topic started by: BertTrack on March 09, 2020, 02:11:18 AM
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My 2016 FX seems to have a problem with it's internal charges and DC/DC converter. Unfortunatly due to circumstances i wasn't able to bring the bike into the shop fast enough and now my 2 batteries have 26 volt remaining. Anyone know of an option to slowly bring them to a usable state? Besides having Zero redo them?
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The Delta Quiq charger will supposedly recover batteries down to 24v
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I have that charger and direct connector to charge the batteries outside of the bike. But no go. Won't charge it.
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If you live near another modular bike u can try swapping packs. Maybe that could do the trick. Where do you live.
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I believe I've heard through the grape vine that the BMS is programmed to kill the batteries to 24V if it gets too far out of spec as a last ditch effort. I would not try to recover them as some cells have likely completely shorted.
The Delta Quiq charger will supposedly recover batteries down to 24v
What makes you say that? I'm curious to learn more about that story.
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I was just going by what was said in the Unofficial Zero Manual ( https://zeromanual.com/wiki/Zero_Quick_Charger ), but I also found this on Delta's own site.
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Those are different chargers. It's talking about a product line and what specific variants are available. They make 24VDC and 48VDC (etc.) chargers, but the QuiQ's sold for our Zeros are not those (though they look the same).
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Look again, the deep discharge recovery voltage for the 96V model that Zeros use goes down to 24V.
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I see it, but I do not think it applies to our chemistry. Perhaps some very robust Lead Acid or NiMH constructions can withstand having a 96V system discharged that low, but that would be 0.86V/cell on our 28S packs.. chances are quite a few cells would be degraded beyond use (in an EV) if it sat that way for any appreciable amount of time. The BMS can't balance fast enough for use after that and there'd be a few weak cells.
While I don't trust this source entirely, here is my reasoning from another source:
"Do not boost lithium-based batteries back to life that have dwelled below 1.5V/cell for a week or longer."
https://batteryuniversity.com/learn/article/low_voltage_cut_off
You can purchase a Delta Quiq 96V charger set up for li- chemistries and it may work, but I don't think it has the same algorithm as the one Zero sells. I'm pretty sure there are different algorithms depending on each chemistry even of the same product line and submodel from Delta (the QuiQ 1000 96V). You can try to recover your battery at your own risk, but be prepared.
On a side note I'm surprised to read that Optima encourages customers to recover some of their AGM lead acid batteries from a deep discharge, despite the usual risks (litigation, customer ineptitude, fire). https://www.optimabatteries.com/en-us/support/charging/resuscitate-deeply-discharged-battery
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I wasn't saying it would work, or that it would even be a good idea if it did work, I was just saying that according to the specs given it might be a possibility.