Recent content by MickeySw

As mentioned before, when READY, that voltage should be around 14V (provided by DC/DC)? Might be worth borrowing a multimeter and measure directly across the battery terminals.. Turn it on (READY) leave it in P and take the key with you, unfortunately you can’t lock it..

It used to be a lot more common after failed DC charging sessions. FW upgrades over the years seem to have helped but many drivers got their own OBD dongle/phone app for just such occasions.. Apart from clearing error codes this will allow you to monitor SoH and cell balancing.

It’s generally recommended to fully charge even a new 12V battery before you install it (it may have been on the shelf for some time). If you don’t have an external charger, leave the car in READY for a couple of hours. What you read when READY? Is there a charging schedule active?

There will be a lot of errors once you restart the car, usually turning the steering wheel to both extremes will clear most faults, if not, a short drive should do the trick..

There is a good chance that the four year old 12V aux is causing the problem, make sure you fully charge the new battery before you install it.

I’m pretty certain that (near) perfect top balancing is possible with degraded cells; SoH of my 15 year old EV is around 80%, yet top balancing is within a few milivolts?? A HV battery is usually made up of a bunch of individual cells all connected in series. The current going through each...

Balancing (at least the way I understand it) commences when charging is completed (I.e. when the first cell reaches the cut-off voltage). Passive balancing: The BMS then determines the lowest cell voltage and turns on the blalancing resistors of every cell above that level and thus ‘bleeds off’...

Afaik the flat LFP charge/discharge curves are challenging for the BMS when it comes to accurate measure SoC, however I wouldn’t have thought that this also affects top balancing?

You mean current reduction? Is the ZS using active balancing, passive methods usually doesn’t require extra energy? Out of curiosity, what was your min/max cell voltage after the failed calibration After a successful balancing session all cells should be at the same level (within a few...

Charging to 100% isn’t the issue, I’m more concerned about the resulting 136mV difference after @doubledroz ’s failed calibration? I don’t know what level of imbalance @doubledroz ‘s cells were before but it looks like they are way worse now? Looking directly at cell voltages may prove more...

Isn’t it a bit concerning that the very procedure to increase battery longevity can have the opposite effect? Any advice on how an EV ‘noob’ with no diagnostic tools is going to verify that the ‘proper equalisation charge’ has completed correctly?

Can you elaborate on the above? No doubt ‘proper equalisation’ will optimise battery performance, but the whole idea of a BMS calibration is to correct an inaccurate battery capacity, I.e. there is no permanent loss. Apologies for using the MG5 as an example but I don’t have the details for a...

The battery is always charged to 100% SoC, however the actual capacity is a bit higher than the spec but all calculations, (range, SoH) are done using the nominal (lower) value. Once the degradation has ‘used up’ the ‘overcapacity’ SoH will start dropping. There is some ‘anecdotal evidence’ as...

EV manufacturers deliberately underreport the max capacity of a HV battery by a few %, therefore SoH will remain 100% until that ‘buffer’ is ‘used up’. I agree, a SoH of 100% is somewhat ‘meaningless’, however once you drop below 100%, SoH will become accurate. Imho the only way for the BMS to...

Any chance you have the current min/max cell voltage values?