Another Top Balancing question?

[Solarfun4jim]

If top balancing an 8 cell x 280AH pack in parallel with a bench top power supply(10A output), setting the voltage to 3.6v and knowing it will take several weeks to charge the pack to that point(im in no hurry), what harm can be done to the cells if the pack is left for 24hours, still connected to the supply after the pack has reached 3.6v and the current has dropped very close to zero? I'm presuming the 'floating' at 3.6v for an extended 24hour period, wont cause much harm as a one off event, whilst doing the initial top balance? (i realise these should be floated between 3.35-3.4v normally.)
A lot of other methods discussed, seems to be to speed up the process. If 'time' isn't a factor, then a slow 'balanced' rise of all cells up to 3.6v over a few weeks would appear to be 'safest' for the begginer?
Reason i ask, is that i was intending to set this method up and check once/twice per day only.
Anyone care to explain the possible pitfalls in this?

 

[snoobler]

8 * 280 = 2240Ah

LFP is fully charged at 0.05C, i.e., at 112A and 3.65V, the 8P battery is fully charged.

There have been concerns that extended "float" charging can damage batteries causing bloat. I figure the risk is low in your situation.

IMHO, there is ZERO benefit to a 24 hour dwell and very small risk. Your cells are OVERcharged BEFORE they hit 3.65V @ 10A.

Given the relative ease of taking a single voltage measurement, I'd shoot for about every 12 hours.

 

[Solarfun4jim]

8 * 280 = 2240Ah

LFP is fully charged at 0.05C, i.e., at 112A and 3.65V, the 8P battery is fully charged.

There have been concerns that extended "float" charging can damage batteries causing bloat. I figure the risk is low in your situation.

IMHO, there is ZERO benefit to a 24 hour dwell and very small risk. Your cells are OVERcharged BEFORE they hit 3.65V @ 10A.

Given the relative ease of taking a single voltage measurement, I'd shoot for about every 12 hours.

Thanks snoobler, however i note your saying that the cells are overcharged before they hit 3.65v. Using this slow parallel bench top power supply charge method, just how exactly would you conduct it? Only reason i was aiming at 3.6v top balance was to give me headroom for normal charging to 3.5v/cell thereafter, thus allowing some capacity for a chargery balance function to happen up to the cut off point. If memory serves me correct, if i only charge to 3.4v, there will be very little balancing function available as it appears to take place mainly in the 'knees'. Is my thinking on this wrong?
In normal operation, i was hoping to just charge to 3.5v/cell, then immediately terminate without any further absorbtion or float period, so that at rest i might then have approx 3.325v(90% SOC).
Having zero experience with any type of battery, this is all guess work for me.
Appreciate your take on it.

 

[snoobler]

A means of charging your battery would be to apply a 112A current and then terminate it the moment the cells reached 3.65V as it is truly fully charged, and any additional input is not retained as usable charge.

You're only applying 10A at most. That means that by the time you're at 3.65V, you've been full for awhile.

Just continue on your course, checking cell voltage every 12 hours via direct measurement. Once your cell hits 3.65, terminate charge.