Ezgo Express 72v Charging question.

[BadChoices03]

So i recently bought a brand new Express 72v, got it home and drove it around for a week, then out of nowhere, the charge meter would only read 78%, charged overnight, in the morning its still on 78%. Call the dealer, since its brand new, and they came and picked it up. First they called me and said the gauge was bad, would replace under warranty. Replaced gauge and still read 78% on the new one. They tested the batteries, one of them read a bit low, so they replaced it, still read 78%.

It has been in there a week now, and yesterday i was told that after speaking to EzGo, they determined that the cart is in fact fully charged, but the way the gauge works is that it has to go below 75% before it will reset back to 100%. So they said if i take the cart out, come back and the gauge reads 80%, and i plug it in, it wont go to 100% even if the cart is fully charged. Suggested I wait until the gauge goes below 75% before i plug it in.

WTF? has anyone heard of this before?

[BobBoyce]

Originally Posted by BadChoices03

So i recently bought a brand new Express 72v, got it home and drove it around for a week, then out of nowhere, the charge meter would only read 78%, charged overnight, in the morning its still on 78%. Call the dealer, since its brand new, and they came and picked it up. First they called me and said the gauge was bad, would replace under warranty. Replaced gauge and still read 78% on the new one. They tested the batteries, one of them read a bit low, so they replaced it, still read 78%.

It has been in there a week now, and yesterday i was told that after speaking to EzGo, they determined that the cart is in fact fully charged, but the way the gauge works is that it has to go below 75% before it will reset back to 100%. So they said if i take the cart out, come back and the gauge reads 80%, and i plug it in, it wont go to 100% even if the cart is fully charged. Suggested I wait until the gauge goes below 75% before i plug it in.

WTF? has anyone heard of this before?

They started this with the 72V onboard chargers, then migrated it to the external chargers in mid-2019.

Every 72V is programmed to consider the pack fully charged after it exceeds 75%. It is rediculous because sulphation starts forming when the pack is under 80% - 90%! It's like E-Z-GO is intentionally wanting new battery packs to fail prematurely!

I have been reprogramming them to fully charge the pack until it exceeds 95% SOC and that has solved the issue. A dealer cannot reprogram that setting.

[BadChoices03]

Originally Posted by BobBoyce

They started this with the 72V onboard chargers, then migrated it to the external chargers in mid-2019.

Every 72V is programmed to consider the pack fully charged after it exceeds 75%. It is rediculous because sulphation starts forming when the pack is under 80% - 90%! It's like E-Z-GO is intentionally wanting new battery packs to fail prematurely!

I have been reprogramming them to fully charge the pack until it exceeds 95% SOC and that has solved the issue. A dealer cannot reprogram that setting.

The part that is confusing me though, is for the first week the gauge would read 100% every time i unplugged it from the charger each morning, this particular morning the QuiQ charger was flashing (double red flash) which according to the owners manual is low voltage from the cart. I turn the cart on and it reads 78%. I reset the charger plugged it in, checked it in the evening, no flash from the charger, charger indicated batteries are fully charged, turn key, gauge still at 78%.

[BobBoyce]

Originally Posted by BadChoices03

The part that is confusing me though, is for the first week the gauge would read 100% every time i unplugged it from the charger each morning, this particular morning the QuiQ charger was flashing (double red flash) which according to the owners manual is low voltage from the cart. I turn the cart on and it reads 78%. I reset the charger plugged it in, checked it in the evening, no flash from the charger, charger indicated batteries are fully charged, turn key, gauge still at 78%.

The confusion is because they are two seperate systems. The charger and the SOC guage. The charger is a smart device, with its own programming. And the SOC guage is just a display unit, that is told what to display by the controller. You don't really need to understand how it is integrated, just know that it is. The controller monitors power consumed vs power replaced by the charger. It takes a while for your controller to add up that the charger power in to replace the power consumed by the cart was falling behind. I'm doing my best to try to explain this in simple terms. When I reprogram these carts for more speed and power, I also go in there and fix the mistakes made in the original programming that causes these sort of issues.

[cgtech]

I had to do the same thing on the AC "star" carts to correct the "real world" batteries & soc meter. Not sure if I should consider myself "lucky" that I could fix that, or "un lucky" that I was dealing with a "star" cart.

[BobBoyce]

Originally Posted by cgtech

I had to do the same thing on the AC "star" carts to correct the "real world" batteries & soc meter. Not sure if I should consider myself "lucky" that I could fix that, or "un lucky" that I was dealing with a "star" cart.

I feel sorry for you. I refuse to work on them. I've dealt with the lack of a real VCL in these chinese clones of the Curtis controllers that bear the Curtis name but not the real Curtis OS or VCL.