To Buy a PL8 - Accessories

[ICEUK]

Bm, do you have a copy of the 24v XLR MK gel preset, i have pl8 amd fusion 600 watt psu. Just need to plug laptop in.

Thx

[sin85]

thanks. it will last for next 4 weeks then i switch to lithium first in cro and upon return to aus. the charger for cro will be pl8 and i will follow your advice and do 8 cells @ 3.55v gell.

[Burgerman]

12A max allowed, wont set higher.
1.55V overvoltage per cell gives error stop.
Charge voltage 2.35Vpc (14.1V/28.2V for 20C Max batt temp. Reduce V if warmer)
Termination is 8 hours Max time limit, or 750th C (100mA) based on a GRP24 Batt (whichever occurs first).
No float/trickle needed.
Min charge voltage, 1.5V Per cell.
Complete charge timeout 16 hours.
Discharge timeout 4 days.

This is for regular cyclic (30 to 80% discharge) use.
To do a top up, from storage ever 2 weeks, or to top up a chair thats done say 10% discharge, reduce CV time limit to 2 hours and 4 hours respectively.

If battery is old or sulfated, the current may begin to climb instead of fall during the end of CV. If this is the case, then replace battery, or reduce CV voltage and allow battery to cool for a few hours. Its called thermal runaway... You dont want that.

This preset. Only via XLR, to charge with Anderson you really should increase Amps to 20 or 25 so different preset needed...

Remove.zip

[Gnomatic]

BM, on the MK XLR preset I have is set to 70mA termination or 1000th C. Also, it came set to have a 2hr trickle once 70mA current is reached. The CV timeout was set to 8hrs, but I turned that off cause lead bricks were new. I'll put it back to 8hrs. (didn't know to put the CV timeout down to 2hr-4hr during top ups when the chair isn't in use)

These lead bricks have only been used daily for about 1 - 1.5 months since I got them new for my secondary chair last spring. They were charged by a dumb charger for a few days to a week, but after that only with the PL8 XLR preset I got here.

I was in my secondary chair the other day and ran a lot of errands etc. By the time I got home the chair was sluggish and the joystick lights were in the red. I hooked it up that night and charged with the PL8 XLR preset. Next morning The CV stage had yet to reach termination, let alone trickle. At that point I unplugged the charger so I could use the chair.

The PL8 software said I returned a bit over 45Ah to the batteries. So I think my lead bricks are still in pretty decent shape.

Either way, my lithium chair is back in action after a bit of downtime for servicing and tweaks. Just in time for summer.

[Burgerman]

BM, on the MK XLR preset I have is set to 70mA termination or 1000th C.

I still have mine set to 1000th. They dont reach it very often. So the 8 hour limit stops the charge. So 750 probably better. Even 500th C is OK if they do not reach 750th. You are aiming for around a 6 to 8 hour CV stage, and the charge to end when the current doesent drop further. Previous use, depth of discharge, temperature, charge voltage all affect this. Its a balance. I am just doing a best guess. Fine tune termination current for as close to 6 to 8 hours on a deep cycle day. It will change as they age. Remember too, a warmer day means it will not drop as low... So you should ideally drop voltage to say 13.9V per battery. Today for eg, my room is 23C but the battery is about 4 or 5 degrees warmer as I have been busy!

Also, it came set to have a 2hr trickle once 70mA current is reached. The CV timeout was set to 8hrs, but I turned that off cause lead bricks were new. I'll put it back to 8hrs. (didn't know to put the CV timeout down to 2hr-4hr during top ups when the chair isn't in use)

You can keep the trickle if you want. Its not doing much if the battery has already spent 8 hours at CV. But dont turn the 8 hours off. (Actually MK say 12h CV limit!) but thats excessive. You can turn that trickle off if you want. What its trying to do is remove the last tiny bit of sulfation without current starting to climb. If batteries are healthy, and newish its not needed. If they are used, and sulfated, that cc at the end will return some lead sulfate back to the acid each charge safely. Its a slight low current overcharge. If there isnt any sulfation, it just causes gassing, recombination, heat. But its only a tiny amount. 1/8th of an Ah over 2 hours!

[Burgerman]

The reason you only want say 2 hours at CV on an almost full battery, but 8 hours CV on a deeply discharged battery is the very same peukert we get on discharge. Only in reverse. If a battery is say 20% discharged, then there will likely be very little surface charge (peukert build up.) The spongy lead paste filling the grids, will still be pretty charged up away from the plate/acid interface. So you only need charge the acid/plate interface. Theres nothing else thats delayed waitng to catch up. So if you keep charging the battery warms through recombination, and current will not fall.

If its discharged a lot, over a long days use, the spongy lead deep inside the plates, and the electrolyte a long way from the leadplate/acid interface will be discharged too. As you replace power, you charge that lead/acid contact point first. It it then takes many hours before this charge is transfered to (propagate to) the inner lead sponge, and throughout the gel further from the interface. So it takes a lot longer at CV to charge a deeply discharged battery. Whats more, 24 hours later, you may well be able to add some more power back in. Albeit not much. After the surface charge has had time to soak into the deeper electroyte/lead plate. Thats why we hold it as long as possible and a low termination current in heavy cyclic use.

So 1000thC OR 750thC are both OK as the 8 hour limit will likely be reached first. Which is fine, it means its done. On a newish regularly used battery it will reach 1000thC because mine do. Sometimes in 5 or 6 hours. So charge ends as that too is done.

[ICEUK]

Bm. I cant open the file. I have downloaded winzip? Do i have to rename file extension?

[ICEUK]

Its ok sorte itt

[ICEUK]

I camt get rid of the zip extension. I try amd rename file but it dont show me the zip part. Hate computers.

[ICEUK]

Finally sorted, stupid friggin windows was hiding file extension.

Bm, my batteries are 6 years old (-: its just my back up chair. I know they are not much good but im holding off replacing them as i would like to try and have a blast at going lithuim.

[Burgerman]

Computer set up in dummy mode?

That screws up most things. How can you work like that?

[LROBBINS]

To see that extension, find the "Folder Options" in Windows Explorer (the way to find it differs with OS version - thanks MS), open the "View" pane and unclick the item that says "Hide extensions for known file types". If you do this in the root of your drive and then "Apply to folders" this change will work throughout the disc.

[ICEUK]

Thx.

I did manage to figure it out but it just pisses you off. Its a fresh install of win10. Crappie old laptop i leave in shed, it might persuade thieves to take it instead of my tools (-: