Very conservative gom

[Pebblefeline]

Do people find that their mg 5 has more power left than indicated at low charge?

For instance charging to 100 percent from 9 percent took between 44 and 48 kWh (depending on losses). 48 delivered by Ohme so lose 10 percent ish.

My battery takes about 55 kWh once degradation is accounted for.

I should have had about 4.9 kWh remaining at 9 percent but it looks like I had around 10 kWh
Or 18 percent remaining.

Do you find the same?

Is this normal bms behaviour?

Just interested

 

[MickeySw]

Is this normal bms behaviour?

I think so, battery capacity fluctuates with seasonal temperatures changes.

 

[workwithtoby]

At low battery, I do get different readings from car dashboard vs ABRP via dongle. e.g 5% on car vs 8% on dongle.

 

[workwithtoby]

Do people find that their mg 5 has more power left than indicated at low charge?

For instance charging to 100 percent from 9 percent took between 44 and 48 kWh (depending on losses). 48 delivered by Ohme so lose 10 percent ish.

My battery takes about 55 kWh once degradation is accounted for.

I should have had about 4.9 kWh remaining at 9 percent but it looks like I had around 10 kWh
Or 18 percent remaining.

Do you find the same?

Is this normal bms behaviour?

Just interested

I guess it might depend on overall battery SOH as well?

 

[Pebblefeline]

Yeah I have factored my current soh so I have a capacity of 55kwh roughly

It just seems consistently I have more power remaining than the car indicates.

I have an anal spreadsheet showing journeys and charging so I can claim mileage, and it’s interesting that the car will often use less power than the gom indicates.

Just wondered if anyone else found the same.

ABRP would seem to bear this out as well.

 

[MickeySw]

interesting that the car will often use less power than the gom indicates.

The GOM makes a prediction of range based on past performance, it can therefore only be accurate, if the driving profile doesn’t change.

ABRP would seem to bear this out as well.

Most EVs transmit SoC on different PIDs on the OBD bus, depending on what it’s used for internally, values may vary slightly.

It could well be that the discrepancy @ low SoC is a deliberate ‘buffer’ in the unlikely event one is getting close to 0% SoC?

 

[WigglePig]

I really must sort out some sort of tool to read OBD2 codes (I already have an ELM-based bluetooth dongle so should be able to do this fairly straightforwardly.

This is of interest to me as I have noticed a huge drop in GoM range this winter and I suspected a problem, although the GoM has suddenly started to get much more reasonable in the past fortnight...probably temperature but I want to dig into it before I decide to keep the vehicle!

 

[Gomev]

I really must sort out some sort of tool to read OBD2 codes (I already have an ELM-based bluetooth dongle so should be able to do this fairly straightforwardly.

This is of interest to me as I have noticed a huge drop in GoM range this winter and I suspected a problem, although the GoM has suddenly started to get much more reasonable in the past fortnight...probably temperature but I want to dig into it before I decide to keep the vehicle!

If you have a dongle already just download 'Car Scanner' app, available on Google and Apple. Very simple to use.

We had a recent prolonged period of very cold weather, so the GoM is exactly that, don't take too much heed of it. If you really want to check without using an app and dongle charge to 100% , reset accumulated trip set mode to N and look at GoM. It won't tell you the truth but it will indicate if anything is possibly wrong as it should show WLTP for your model less any degradation.

 

[Wendwell]

For others struggling with the abrreviations above, I have today learned the following:
GOM - Guess-o-meter - a device that estimates remaining milage given the battery charge
ABRP = A Better Route Planner, a website and app designed for Electric Vehicles.
BMS = Battery Management System
Ohme - a brand of charger
SOH = State of Health
SOC = State of Charge
OBD = On Board Diagnostic of an Es. OBD2 is more advanced than OBD1.
ELM - I think refers to a company that made devcies to read On Board Diagnostics
PID = a Proportional, Integral and Derivative controller in an electric vehicle regulates speed.

Spare a thought for those still struggling to find their inner geek.

 

[MickeySw]

ELM - ELM327 microcontroller used in (low cost) OBD dongles
PID = (OBD) Parameter ID

small corrections

 

[Wendwell]

Thanks.
A little knowledge...