Burgerman wrote:Isnt that a GRP24 chair? Then if so you need the Gel MK 74aAh ones.
Before instalation, connect them together 24 hours in parallel. Pos to pos. Neg to neg. To be sure both are equally balanced. They will last longer. And charge often, and EVERY time you use the chair. For as long as you have. Long after the green light comes on if time allows.
Burgerman wrote:According to the manual it is.
Burgerman wrote:If unused, charge 16 to 24 hours MINIMUM, preferably longer every 2 weeks. Because even when turned OFF the control system takes 10 to 20mA all of the time. And that allows the battery to sulfate. Which isnt good.
If you want to leave it a long time unused, disconnect a battery lead. After a full 24 hour charge. That should stay good for 3 to 6 months without charging.
Burgerman wrote:Generally If your charger is a modern one it does 2 things. It charges until after around 6 to 8 hours it says DONE and you get a green light.
At this point your battery is around 95 to 98% charged.
If you leave it connected after the green, it continues at a lower safe long term voltage. It SHOULD drop the charge voltage to around 27.2V indefinitely. Ignore the green.
The reason this matters is because the 2 percent remaing takes a very long time to charge. If the battery is healthy, 16 hours. If its old and never been charged properly can take weeks and may never be recoverable.
So an overnight charge does not complete it. The green light makes you think its done so you can go about your day. That last 2% is lead sulfate still on and inside battery the plates.
Whan you discharge a battery it takes the sulfuric acid and turns it into lead sulfate and lead dioxide. When you charge, the reverse happens. If you do not charge long enough then some lead sulfate remains, and over time it turns into a hard crystaline coating that does not conduct electricity. So you get permanant sulfation, and this builds over time untill the battery is toast. RIP battery.
So even if you only move the chair a few feet, it needs a complete charge. That means typically 20 hours. If you want to leave the charger connected for a week thats OK too. You should periodically if you get the chance.
Burgerman wrote:THat charger above is total overkil for lead alone. We mostly use those for measuring capacity and charging and balancing lithium battery packs.
One of the better chargers for lead is the https://www.victronenergy.com/chargers/ ... 65-charger
This will charge your gel batteries correctly provided you go to the ADVANCED settings and enter the correct parameters.
Ask what those are here if and when you get one.
You will need to solder your own XLR plug onto the cable obviously. Or better still, and for many reasons, add an ANDERSON connector to the chairs battery and the charger instead. Then you can charge at max power. And without the problematic XLR connectors.
Read the manual.
Burgerman wrote:24V, 5/8/13A
Burgerman wrote:5A or 8A via XLR. 13A via Anderson connector preferred.
Burgerman wrote:Then in advanced, and user settings.
For gel, like MK, you would set to any Amps that your connection allows, up to 12 via XLR is permitted, and I think that means 8 in this case. But more = BETTER as faster gives longer time at CV overnight for a fuller charge. So 13A via a better anderson connection.
For cyclic use, and long service life Set CV stage at 28.20 volts max, not higher!
Until it has been sat at 28.2V for 8 hours, or until 1000th of capacity in Amps, (so say 75mA to 150mA) point is reached. Whichever occurs first.
Then FLOAT at 27.6V and STORE at 26.8V indefinitely.
It will take 18 to 24 hours to recharge a deeply discharged battery. And around 12 to 16 minimum if partly discharged.
No soft start, no extra stages, no recovery or overvoltage stages, no desulfate, and def no recondition, or de-stratification. Just CC/CV/Float.
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