WheelchairDriver

Well, I got delayed on making my add on. Pneumonia s.ucked. But I'm back and getting ready to recharge the batteries now. They should be pretty low.

In the meantime, has anyone used something like this to charge batteries in a car?

I don't want to do the normal get adapter, take charge around, so I'm looking for a small affordable charger that I can keep my car for emergency use.

http://www.topmobility.com/mobilecharge ... -p1072.htm

2.5 Amps?

To put say 40Ah back into a 70Ah battery, will take 20 hours as you drive at CC and another 6h at CV. Its too slow to be of any use on anything but a toy. It wont add enough, fast enough so that you would notice.

I use a PL8, which does the same thing, at the correct voltage, at anything up to 30A. So 15x faster. Via XLR set to 12A and 6x faster.

Do note that you can do as Burgerman does and connect a PL8 to the car's charging system; you don't need a separate AC to DC power supply as you would need in the house. If you have an Anderson on your chair, you can, as he just said, charge at up to 30A which will top off your batteries pretty quickly.

Guess I'll get an invertrr. Is there a "good" xlr charger? I am just wanting to keep it in the van.

Explain your needs accurately.

When you say get an inverter, then there are 12v to 110 or 240V AC inverters. Thay are either sine wave or not sine wave (which wont work) that will allow you to charge with your usual powerchairs stock XLR 8A charger. But that wont work unless the engine is running as it will take more power from your vehicle battery than it actually has! And then neither the chair or the car will work...

If you intend powering it from the house you dont need an inverter.

OR

if you use the PL8 then it can be powered straight off your vehicle battery. And charge the chair perfectly. And more efficiently than using an inverter. Only now you get to choose the correct settings. Again the engine will need to be running or the vehice battery will die.

In EVERY case, the battery will need 10 to 16 hours to FULLY charge no matter what charger you use. Or it will have a very short life...

My purpose is for just quick charges. For example: tonight I am going somewhere an hour away , and my factory batteries are already low. So I would like to be able to charge while I'm on the road.

It will mainly be for spur of the moment needs. That's why I would like an inexpensive charger to charge the factory batteries.

When the pack is done, I would use the pl8 via anderson but when there isn't a pack, I want to use the factory charge port.

I was looking at this inverter.
https://smile.amazon.com/BESTEK-300W-Po ... er+for+car

You cant take 300 watts from a car cigar lighter socket... And thats 300 out, so 350 in. So it will need around 30A to power it minimum if you plug a 300 watt/8A charger into it. And it probably wont work as its not a sine wave AC output.

It will need connecting directly to a car battery.

If you are going to do that, then you may as well just use the PL8! Make up a lead, with an XLR on one end, and set it to 12A max. So you can charge the chair at a sensible speed as you drive.

Burgerman wrote:If you are going to do that, then you may as well just use the PL8! Make up a lead, with an XLR on one end, and set it to 12A max. So you can charge the chair at a sensible speed as you drive.

Ok I'll do this method.

Or you can do as Burgerman has described elsewhere and re-wire the chair with two Andersons and a removable link so that the batteries can be put in parallel and charged directly from the cars alternator - no charger at all.

Old method...
http://www.wheelchairdriver.com/charge- ... om-car.htm

Newer method is what you need, (but still a decade old) but read old one first...
http://www.wheelchairdriver.com/faster- ... arging.htm

Hi to All.
I want to create add on pack to my Permobil C500S wheelchair.
Now I have 70 Ah EverExceed 1270 AGM batteries.
I have a few questions.

1. Can I use these LiFePO4 batteries? 4 units connected 2x2, 24 Ah.



2. Where have I connect the pack to? Main batteries connectors?

3. Can I use my ProMariner ProSport 12 charger for both - main batteries and the pack? Now it in AGM 14.6V mode.

Thanks.

They are physically big for the Ah they will give you. You are swapping 2x lead,12Ah size for lithium thats only 12Ah as well. One of the advantages of ithium is it has higher energy density so you can get more Ah into the same volume. So no gain here... So physically large for its capacity.

And they contain stupid problematic BMS (4 of them!) so I wish you much luck, and you may well have reliability issues and will have a short service but at least that wont stop the chair as you try to climb a ramp or something as the lead will take over. Takes up much space for small Ah compared to something like expresso uses. You can build a better setup thats more compact, for less money too.

You just need to add an anderson or other connector to the 24V system on your chair to connect to.

Burgerman wrote:And they contain stupid problematic BMS (4 of them!)

Why BMS are bad?

viewtopic.php?f=2&t=1813

Read the first few posts, follow links. CAREFULLY.

Another BIG problem that I'm sort of surprised that BM didn't pick up on - if you look at the spec chart, it says the MAXIMUM peak discharge is only 40A.... Given that the controllers in our chairs can pull MUCH higher currents when turning or other high load situations, you are likely to either damage the batteries, or (more likely) have the BMS in them shut you down every time you try doing anything that draws a high current....

I also notice a 50mOhm internal resistance spec - that is disgustingly high even by lead brick standards.... IOW big voltage drops as the current draw goes up - potentially leading to controller problems at worst, and poor performance at best...

This is a pretty typical set of issues that we see in almost every 'one piece' lithium replacement battery.... It is WHY we consistently tell people to build their own packs - without a BMS....

ex-Gooserider

Hi, I have mk gel battery, what care should I have to prolong your life ?, the pl8 charger serves to last me longer? while I'm buying, the Addon on

Thanks

better off with this kind of Cells for an ADD ON - you can fit alot more in same space - 80ah will make a huge difference

viewtopic.php?f=2&t=8390

Hi, I have mk gel battery, what care should I have to prolong your life ?

Wrong thread, but:

MK gel, CYCLIC use:
Charge at up to 24A ideally, but limit to 12A via XLR connector IN CC STAGE (called BULK by ignorant people!).
CV stage (called Absorption by ignorant people) at 25 centigrade battery, 20C room, for healthy newish battery, 28.00 to 28.20V max until 8 hours, or current falls to 1000th of capacity , so 70mA on a 70Ah battery. Whichever occurs sooner. No float needed. Limit to 4 hours CV for a light discharge or top up.

Or terminate at .4A to .5A and 27.0V float. (Slower).

The above is the best you can do without a laboratory!
Heres the tech spec sheet.
http://www.wheelchairdriver.com/MK1.pdf

Heres what happens if voltage is just a tiny bit too high... Study carefully.

I'll read it carefully, but this is checked with the PowerLab 8 right? Thank you

You are not making any sense!

It doesent matter what charger you use, those are the charging requirements for the best service life.

Burgerman wrote:You are not making any sense!

It doesent matter what charger you use, those are the charging requirements for the best service life.

I said it because I have a liberty chair 312 and jazzy select gt, I would not know how to check that, and the pl8 charger I want to use it for the express addon.
Excuse me, I'm new to this.

Hi, I have mk gel battery, what care should I have to prolong your life ?, the pl8 charger serves to last me longer? while I'm buying, the Addon on

Thanks

I replied to this. Those are the settings you asked about. You set the PL8 to do exactly this.

Use one of the lead presets that I have posted in many places here, or ask me if you want another. What Ah are these MKs? What temperature is it where you are charging? Are you charging via XLR port?

Just charged my little pack up after its been sitting for about a year. It started of stored about 85% capacity.
Down to 27V

Cell grp 2 has a little higher self discharge than the rest, but after a year thats not bad. Although a 100mA BMS would have needed about a week to straighten that out... But a 1A balance does it reasonably quick.

guess where this is going

Sorry for not posting for a long time i'm a lot lazier these days

12,000mAh +12Ah per pack, still waiting on XT90 connectors and anderson connectors

Hoping to put pack on the chair I am currently sitting in (not the old one of the same model) behind the casters, below the seat. Bought Battery jump starters from Amazon, 12Ah, £35 for the first one, which was damaged, couldn't plug the booster lead in. Got a free replacement. Second booster was £46, Third booster was also £46, ended up with 4 boosters. I just want to make an emergency add on. This chair has already had new 55Ah AGM batteries as the previous new ones failed after 5 months, and these new ones (warranty replacement) have already started to fail @ 6miles, cold not helping. I was also intending to put bug eyed 3w LED fog lights on, using one of the boosters as the power source.

Boosters?

As in 3S Lipo fire hazards? Those wont work well. They are 25V fully charged, but drop fast. Your chair stops about 23.5 to 24v. So you will only be able to use about half the capacity or a little less. You need 7S for 24V systems. Try it. Your battery meter will tell you its dead at about 2/3rds charged. Other issue is that they only do a few hundred cycles. OK for emergency, but not regular use.

shouldn't half the capacity still be able to accomplish half a mile of gradual hill. I lose a green light on the controller at the bottom of Horsham Road Junction South Street, Dorking, then before the 1/4 of a mile of hill I have lost all the lights, Turn off, wait a little bit, go a little bit further, then repeat. At the top of the Horsham Road (Flint Hill) it's all down hill from there, and even in limp mode I can get home. But at that point the tiniest obstacle.

So would my jump starters actually blow up?
Thanks for being very quick BM

No, but they wont help much. Voltage too low. They are nominal 3.7v per cell. Thats half way between empty and full. So 3.7V x 6 is 22.2V. And your chair stops rolling before this. So you will gain about 6Ah total usble. So about 2 miles extra at a guess?

You would have done much better to build a real ADDON, with 8 LIFE cells, or say 2x or 4x hobby king 8400mah life packs, or just bought some decent lead batteries. Although they may help a tiny bit with hills.