Minimo autofold

[duke1]

hi id guess at one or two dead cells so confusing any on board diagnostics,im no expert on lithiums though,does yours have have a bms? (battery management system) as they are very prone to faults and buggering up perfectly good cells.good luck

[woodygb]

Here is a table showing state of charge ( Lipoly ) vs pack voltage...note how the volts difference between FULL on the 6s and 20% of charge ( lowest that you should go is only 3v..

[Burgerman]

Thats a 7S pack in the scooter.

So fully charged is 4.2V per cell. So 29.40V and not even a tenth of a volt more. Or you may cause a fire.
As you take it off the charger it will fall slightly.
When the LOWEST CELL reaches 3.7V thats it. Go lower at your peril. Lithium cells dont like it. Once to 3V (LiPo) or 2.7V (Lithium Ion like laptop cells) will ruin them. Thats a LOWEST for the full pack of 25.90 advisable. That does NOT mean that the lowest cell will not drop too low first. So a BMS might stop you before this.

[GusGf]

Thats a 7S pack in the scooter.

So fully charged is 4.2V per cell. So 29.40V and not even a tenth of a volt more. Or you may cause a fire.
As you take it off the charger it will fall slightly.
When the LOWEST CELL reaches 3.7V thats it. Go lower at your peril. Lithium cells dont like it. Once to 3V (LiPo) or 2.7V (Lithium Ion like laptop cells) will ruin them. Thats a LOWEST for the full pack of 25.90 advisable. That does NOT mean that the lowest cell will not drop too low first. So a BMS might stop you before this.

That's a bit confusing, not what you said but the fact it doesn't tally with the manual which is saying the battery is 24v. But it would explain my readings.

[woodygb]

Pop the lid on the battery and look inside.

[Burgerman]

A battery voltage label is just a rough description.

Mobility devices are nominally 24V. Because they traditionally used 12V lead batteries. Which are not 12V either... A lead battery voltage when fully charged is approx 12.9 to 13.3V. x2 in series of course.

A LIFEPO4 cell is nominally a 3.2V cell. So 8 of these = 25.6. The closest you can get to a 24V lead battery.
A Lithium ion cell and LiPo cells and there are various types are generally 3.7V per cell. So now 7 of these give you your NOMINAL 25.9V. Thats not its highest voltage, or its lowest. Regardless of the 24V label.

[GusGf]

I have taken a quick look inside but hopefully tomorrow in work we can have a better luck and identify what's going on. What you said Burgerman seems to make a lot of sense as to what I'm seeing reading wise. Will update

[Burgerman]

You will find 7, 14, or other multiples of 7 cells...

And a useless BMS. If you want to keep it simple you will have to keep that. And replace the cells. Its easier to buy a new battery.

[GusGf]

You will find 7, 14, or other multiples of 7 cells...

And a useless BMS. If you want to keep it simple you will have to keep that. And replace the cells. Its easier to buy a new battery.

I think you are right I'm best replacing the full pack. I'll be looking for a 7S4P including a BMS to keep it simple as you said. Would you have any suggestions for battery pack makes that would be reliable?

[Burgerman]

Whatever it has now. Replace. Plug and play.

[scootntootn]

The TGA Minimo series are actually Heartway S19. There are at least three different models.