Phantom cell failure or Economy 7 Syndrome?

[Grumpy-b]

We run two Electriques 56 weeks a year. Each does about 40 miles a working day. In the summer we can do this without a charge at the mid point (Work).
I have seen a few occasions when checking the Battery Pack voltages , you would assume that a faulty cell is there. Sometimes they are. Yesterday I took out the lower front pack convinced I was going to be changing at least one cell. Charge sat at 45%. Checking each battery cell under load, all seemed good .But there were some small differences in cell voltages.
What I think may be happening is that since we normally charge on economy 7 and a full charge is going to take atleast 4+ hours, this means that even if the controller thinks it needs a Balance charge, its never going to get it. So the pack never gets its full balance charge. Leading to a greater degree of out of balance. Solution is for the vehicles to get a periodic no eco 7 charge or an actual Balance charge.

The journey continues.
Grumpy-b

[ChrisB]

Interesting, so are you saying the supply is stopped at times before the vans finshed its charge then.

I've found in the past if the vans charge is interupted before its finished more than about 3times then it forces a EQ charge IF that charge is subsequently intrupted it then adds the time it should have EQ'd to the next charge and so on.

I've known a EQ charge to last as long 12hrs before now due to me intrupting the charge, I think the the charger does keeps adding the EQ time to the main charge until it gets back to its normal state.

ChrisB

[Grumpy-b]

Yes my eco 7 is switched on about midnight and off about 7am. So with a full charge its never going to get the Balance charge, which as you say can itself take 12 hrs.

Grumpy-b

[ChrisB]

Ah so that might be the problem then, while I charge on eco7 I'm not governed by the switch off time as my socket is live all the time and thus is timed on at midnight but the off time is midday, thus the van pretty much always gets a full charge and I rely on van switching off.
When it does its regular EQ charge of a few extra hours it doesnt matter although it can be done on peak rate but its only pulsing around 6amps then so I recon its better to let it do a few hours on 6amp pulsing peak rate than not allow it to and the EQ charge time ends up building up on the controller.

ChrisB

[Grumpy-b]

My sockets for the vans are switched by the eco 7 circuit which has its own consumer unit. We also have a permanemt live from the main consumer unit
We are now going to adopt a once a week plug into power before we go to bed, then most of the charge will be off peak, but it will charge beyond. That way hopefully they will get a full and extra charge as needed.
This is a danger as Im sure it may be the cause of some of the weaker cells being finally seen off. SO its going to be worth the slightly extra cost to get the cells working more effectively.

Grumpy-b

[ChrisB]

I dont think the extra charging will damage the weaker cells if anything I'd think running them undercharged is likely to cause more issues, unless of course the weaker ones are using more water and thus you could end up drying them out ?

But I'd think as long as your watering is regular then they should be OK.

One reason I opted for a always live but timed on socket was to avoid the chance the van wouldnt be able to complete its cycle as I had slight issues with the 7hr switched option and it not being able to complete a EQ charge correctly.

ChrisB