PL8 101 Dumb chargin chair through XLR

[Dan]

I wanna be sure of the basic setting for the PL8 just charging a chair with two gel batteries. Without computer control/monitor. Fist time using the charger I'm not 100% on the settings.

Lead 12V SLA
Parallel packs? Set to 2P for two 12V batteries?
Charge rate 5A 2P = 10A
Set Dsch rate, comes up as 3A 2P = 6A
Start Charge Only?
Must use bananas and same S count?

[Burgerman]

Dont use parallel packs. It does funny things...

To charge gel via the XLR you need this REMOVE.ZIP:

[Burgerman]

>>I wanna be sure of the basic setting for the PL8 just charging a chair with two gel batteries. Without computer control/monitor. Fist time using the charger I'm not 100% on the settings.

*You need that preset above loading with a PC first. You do mean Gel, not AGM?

>>Lead 12V SLA
*No its all wrong. And has some voltage limits that will perodically give you wrong cell count errors etc.
Use the preset above. MANY things carefully set including around half a dozen invisible ones...

>>Parallel packs? Set to 2P for two 12V batteries?
*Nope, your batteries are in series... 12S. You have a 73Ah 24V 12S battery. And Parallel charge does odd things to termination point so best to never use it alongside a manually chosen termination point.

>>Charge rate 5A 2P = 10A
*You are charging in SERIES. So no. You need 12A max as thats what the XLR connector is safe with. 10 to 12A is fine. As already set up in the preset above. You can use it AS IS.

>>Set Dsch rate, comes up as 3A 2P = 6A
*Nope. But all set correctly, voltages, type, discharge rate, cell count, limits, time limits, CV time limit, trickle, etc. and a bunch of hidden stuff in that preset.

>Start Charge Only?
>Must use bananas and same S count?

*Not with that preset! Its all wrong in so many ways. Use the one attached above.
Then yes, charge, use bananas, NO PARALLEL, and 12S...

[woodygb]

This may help with the cell count confusion .

A 12V WET CELL , AGM or GEL battery is made up of 6 cells of around 2 VOLTS connected in series ( 6S ).... 6 X 2v = 12 v.

So two off 12v batteries will have a cell count of 12 in series or 12S.

[Gnomatic]

Good stuff.

So what is it about lead acid chemistry that allows it to "self balance" itself compared to lithium cells?

[Burgerman]

Once a cell is full it cant get any more full. So a controlled level of OVERCHARGE on the complete battery drags all the low cells up to the full level. While overcharging the already full ones... You dont need to read further!

A full lead sealed AGM/gel battery is around 13.2V. We charge them at 14.1 gel, 14.4 AGM, 14.7 Pure lead like Odyssey/Optima. Because its the highest voltage the cells can safely be at.

So thats a higher charge Voltage level than a full battery. On a lead based battery all that happens is that it starts to makes a little gas. It splits the water in the electrolyte into oxygen and hydrogen. This is recombined back into water again inside the battery, and the energy used just gets wasted as heat. And as long as we do this at a very controlled rate (voltage/current), no damage occurs.

The voltages above are choosen carefully, they are just before gassing of the electrolyte becomes too high on each battery type - gel is particularly sensitive here. Once the voltage exceeds a certain point gassing, bubbles in the acid, begins. These batts are sealed. The rate that they can recombine is very limited. And allowing voltage too high or current too high at the end of charge exceeds this. And on gel causes electrolyte bubbles and shrinkage permanently. On AGM types it caused electrolyte loss long term via a pressure release valve, and other damage.

With lithium you cannot do that controlled overcharge at all. As any tiny overcharge of a full cell causes damage very very rapidly. So we need to control the charge so that each cell never exceeds a specific safe voltage. The balance charger does this well. On a LiFePO4 cell thats around 3.6 to 3.65V. On a lithium ion cell thats 4.15 to 4.2V per cell.

[Gnomatic]

Thanks that was an interesting read.

[Burgerman]

HERES A FEW MORE OF MY LEAD PRESETS.

One for XLR connected and MKs limited to 12A max and safe on any chair. (Change volts to 28.80 for AGM or 29.4 for Odyssey/Optima.)
One for charging MK at high amps in series.
One for charging MK at high amps in parallel.
One for charging MK at high amps ONE MK battery.
One for charging Odyssey at high amps ONE battery (and if you reduce volts to 14.4 any AGM deep cycle sealed battery)
One for charging Odyssey at high amps in series 24V
One for charging Odyssey at high amps in parallel at 12V

This IS a zip!

[Burgerman]

Those are for batteries that are cycled fairly deeply.

[expresso]

thanks - i saved those also - just in case i ever need them for lead -

[Burgerman]

May be best to lower the CC trickle from 65mA to 50mA. Because on 2 of my PL8 chargers it keeps going up to 75mA... On that one I lowered it to 50. The difference is the type of power supply. Some are more stable than others.

So let me see your first charge graph if you use them.

[expresso]

sure - if i ever get to use them at all - when i get around to it - maybe i make a charge cable xlr - and one cable with the clamps also -

i am not stressing the lead much since i dont use it really anymore -- indoor chair has lead only - and i just use the dumb charger for it - chair never leaves the house -

the other chair has the lithium ADD ON with lead - so i only charge with the PL8 combined - and the newer chair is full lithium -

if i am lucky i get the bounder with lithium also - i have a few lead loose sitting around - two Gel MK i keep if i need to replace my lithium if the chair ever needs to be serviced - and two PC1500 which i used one summer - and then just sitting around - in case of black out etc, - for lights at least

i have a 12v charger for those - every month i give it a charge - the loose batteries hardly loose alot of charge - they go green after a few mins at most - i leave it for 6 hours each battery anyway -

[Gnomatic]

HERES A FEW MORE OF MY LEAD PRESETS.

One for XLR connected and MKs limited to 12A max and safe on any chair. (Change volts to 28.80 for AGM or 29.4 for Odyssey/Optima.)
One for charging MK at high amps in series.
One for charging MK at high amps in parallel.
One for charging MK at high amps ONE MK battery.
One for charging Odyssey at high amps ONE battery (and if you reduce volts to 14.4 any AGM deep cycle sealed battery)
One for charging Odyssey at high amps in series 24V
One for charging Odyssey at high amps in parallel at 12V

This IS a zip!

Thanks! I had a couple of these from you and expresso I've collected, but its good to have the whole BM PL8 lead brick greatest hits collection in one package.

You said these are for deeply discharged batteries. If just topping off lead bricks, would just lowering the amps be sufficient?

[Burgerman]

No you should lower the mA on the trickle fast finishing part. By 10 or 15mA. In fact you should do that anyway unless heavily cycled. You are aiming to make the finishing (CC trickle) initially drop the voltage a little, then climb back up. Or limit it to 1hour.

[shirley_hkg]

Dont use parallel packs. It does funny things...

To charge gel via the XLR you need this REMOVE.ZIP:

Why need 15mins" verify cell time" ?

[Burgerman]

You may have a cell thats low, below what it considers "safe" and choosing a lower figure on a big pack that is discharged a long way does not allow it time to climb to a high enough level. So you get a stop, and a cell count or cell low, or cell gap error...

[Dan]

Wheelchair services have given me two cheap AGM batteries for my Sunrise Salsa chair. I think in the past the batteries were gel?

Is there a PL8 preset for a single 55Ah AGM battery?
And for two AGM batteries through the XLR port on the chair.
And for a single Gel battery while I'm at it.
Does the supplied 8AMP charger even do AGM?

The batteries are Haze hzb ev12 55ex

[Burgerman]

Wheelchair services have given me two cheap AGM batteries for my Sunrise Salsa chair. I think in the past the batteries were gel?

Correct. The haze ones are not as good. Although they are actually 65Ah at the 20h rate. Rather than 55. But still not as good as gel.

Is there a PL8 preset for a single 55Ah AGM battery?
And for two AGM batteries through the XLR port on the chair.
And for a single Gel battery while I'm at it.

Attached

Does the supplied 8AMP charger even do AGM?

If its the orange and silver one now supplied with the salsa, then it does the following:
8A CC then, 14.40V for 8 hours. Then float at 13.6. Its TIME based, it doesent sense current, so even an alreaady full battery gets an 8 hour charge! And whilst its supplied with the salsa and gel batteries, its voltage is too high for gel. And a little low but OK for AGM.


So you want a stand along charge profile for
1 x 12V battery GEL, say 30A?
1 X 12V battery AGM, say 20A?
And 2x AGM 24V but limited to a 12A max to be safe on XLR charge connections on stock chairs.

If correct I will upload later.

[Dan]

So you want a stand along charge profile for
1 x 12V battery GEL, say 30A?
1 X 12V battery AGM, say 20A?
And 2x AGM 24V but limited to a 12A max to be safe on XLR charge connections on stock chairs.

If correct I will upload later.

Yes, yes and yes. I would like to charge the batteries up indivisibly before fitting and then an XLR setting for when they are in the chair.
Also one for a 12V Gel battery for future use.

Thanks again!

[Burgerman]

I did four.

2 for charging GEL or AGM stand alone, top up or part charge, with 4 hour CV and 10mA termination. Set termination time to 2 hours if topping up an already pretty full battery. Set to 20A for gel, 30A for AGM. Set lower if you want. Want to charge your van battery? Use this agm charge..

2 for charging GEL or AGM 24V via XLR that are hard limited to 12A. You can set less but not more. And 8 hour 1000c termination for 70Ah ish batts. (yours are 65Ah.)