Permobil F5 – Battery Size and Alternative Controls

[fordragon88]

Hello everyone,

My name is Andrei, I am from Moldova. I use a Permobil F5 power wheelchair (2022 model), which I bought second-hand in Europe.

I have two questions:

Does anyone know the maximum internal size of the battery compartment on the Permobil F5? I want to install Battery CS HDC-12-75 VRLA Lead Carbon with dimensions 260 × 169 × 215 mm, and I need to know if they will fit.
https://solars.md/ro/produs/battery-cs-hdc-12-75-vrla-lead-carbon/

I have very weak hands and cannot use the standard joystick well. I am thinking about either a mini joystick or head control, since my movements are very limited. Could you please share your advice or experiences about alternative control options for the Permobil F5?

[Burgerman]

They might fit, but are too high impedance, judging y that 22A inrush current limit.

[fordragon88]

They might fit, but are too high impedance, judging y that 22A inrush current limit.

It's a pity they don't fit, because MK batteries used to be available in Moldova, but they're no longer sold. I'm now looking for other options. I'm also considering using LiFePO4.

[Burgerman]

Well if you look at those they must be able to do 200A current as thats what the 120A X2 controller on the chair can pull from a batery. Max. Depending on programming. And lithim do not like anything in extremes. And so they like to be not full, not empty, no heavy

Ideally you wn to look at double the Ah of lead to achieve that. But you cant do that with drop in lead brick replacements.

When looking at lead batteries look for cycle life (500 @ 80% DoD) and IMPEDANCE of 5 or less. Dont worry about Ah so much.

It's a pity they don't fit, because MK batteries used to be available in Moldova, but they're no longer sold. I'm now looking for other options. I'm also considering using LiFePO4.

What about eBay and the pretty good 80Ah gel Haze batts?

https://www.ebay.co.uk/itm/130633616407

[fordragon88]

Well if you look at those they must be able to do 200A current as thats what the 120A X2 controller on the chair can pull from a batery. Max. Depending on programming. And lithim do not like anything in extremes. And so they like to be not full, not empty, no heavy

Ideally you wn to look at double the Ah of lead to achieve that. But you cant do that with drop in lead brick replacements.

When looking at lead batteries look for cycle life (500 @ 80% DoD) and IMPEDANCE of 5 or less. Dont worry about Ah so much.

It's a pity they don't fit, because MK batteries used to be available in Moldova, but they're no longer sold. I'm now looking for other options. I'm also considering using LiFePO4.

What about eBay and the pretty good 80Ah gel Haze batts?

https://www.ebay.co.uk/itm/130633616407

They don't ship to Moldova. I can order from eBay through a cargo company, but the shipping would be too expensive, as they charge about $16 per kilo. I also forgot that Cargo Company does not deliver batteries.

[Burgerman]

I might be tempted to move elsewhere before putin decides that he wants to continue his obsession. He wants to get the band back together, and you are likely next.

Is there a proper spec sheet for those batteries you linked to?
They could be OK. But no way to really know.

[shirley_hkg]

I'm also considering using LiFePO4.

That's too easy to decide. Forget VRLA.

LiFePO4 is cheaper than lead-acid now. At half of its price, you will get a set of lithium that outlasts your chair, or your life, plus 5X of range … too much to mention.

[rover220]

For special controls an omni would be best but you can use rnet connected versions of the movis micro or multi joysticks.I can supply if required.

[slomobile]

rover, are you aware of any tank style 2 input controls? Either for hands or feet or knees or elbows or any other body part we have 2 of that can operate independently with gross motor in single axis.
Something that might look like https://www.mo-vis.com/products/special ... ot-control but actually uses both handgrips actively. Left hand for left wheel, right hand for right wheel.

I'll be at permobil tomorrow with my United Spinal chapter and want to know which stuff to ask about. I'll try to drag along the carcass of my prone chair to see if they have any ideas.

[fordragon88]

I might be tempted to move elsewhere before putin decides that he wants to continue his obsession. He wants to get the band back together, and you are likely next.

Is there a proper spec sheet for those batteries you linked to?
They could be OK. But no way to really know.

I would gladly leave here, but I just have nowhere to go. I have a house here, it is equipped so that I can easily leave in a wheelchair.

I could only find a link to their manufacturer's website, but the specifications listed there mean nothing to me.
https://csbattery.cn/products/hdc12-75- ... n-battery/

[fordragon88]

For special controls an omni would be best but you can use rnet connected versions of the movis micro or multi joysticks.I can supply if required.

Can you tell me what model of joystick this is, if you have a photo, and how much it costs? I have an SMA, and the progression has reached my hands. Basically, only my wrist works now. I place my hands on a computer mouse, it glides quite easily, and I control it using my wrist and one finger.

[fordragon88]

I'm also considering using LiFePO4.

That's too easy to decide. Forget VRLA.

LiFePO4 is cheaper than lead-acid now. At half of its price, you will get a set of lithium that outlasts your chair, or your life, plus 5X of range … too much to mention.

I completely agree with you, but someone needs to assemble them. I contacted a local assembler, but he only offered me a 60-amp BMS. I told him that wasn't enough. But he doesn't want to install any more, and he's asking 850 euros for 100 Ah.

[martin007]

Welcome fordragon88!

And has the grape harvest started in Moldova?

[fordragon88]

Welcome fordragon88!

And has the grape harvest started in Moldova?

Oh yes, my mother was just picking it today, we don't have much of it. Since it still needs to be looked after, the only one left is the one growing in our yard. My grandfather was a winemaker.

[martin007]

Are you closer to Chisinau or to Transnistria?

[fordragon88]

Are you closer to Chisinau or to Transnistria?

I live on the other side of the country, in the very north. Near the border between Ukraine and Romania, in fact, from my house to the border it’s about 3 kilometers. https://maps.app.goo.gl/aJGYZgcKm3SNYBZV6

[fordragon88]

I might be tempted to move elsewhere before putin decides that he wants to continue his obsession. He wants to get the band back together, and you are likely next.

Is there a proper spec sheet for those batteries you linked to?
They could be OK. But no way to really know.

I would gladly leave here, but I just have nowhere to go. I have a house here, it is equipped so that I can easily leave in a wheelchair.

I could only find a link to their manufacturer's website, but the specifications listed there mean nothing to me.
https://csbattery.cn/products/hdc12-75- ... n-battery/

lead-carbon battery with a 12V rating and a capacity of 75Ah.
Key Specifications

Type: VRLA (Valve Regulated Lead Acid), AGM lead-carbon plates

Capacity: 75Ah (C20)

Voltage: 12V

Dimensions: Length 260 ±1 mm, Width 169 ±1 mm, Height 211 ±1 mm, Total Height 215 ±1 mm

Weight: 26.1 kg ±3%

Design Floating Service Life: ≥ 12 years (at 25°C)

Optimal Depth of Discharge: Up to 50%

Operating Temperature Range: -40°C to +60°C (charge and discharge)

Internal Resistance: ≤7 mΩ (fully charged at 25°C)

Maximum Discharge Current: 450A (5 seconds at 25°C)

Self-discharge Rate: Up to 3% per month at 25°C
Charging Modes

Standby Use: Initial charging current less than 22.5A, voltage range 13.6–13.8V

Cycle Use: Initial charging current less than 22.5A, voltage range 14.4–14.7V

[fordragon88]

Are you closer to Chisinau or to Transnistria?

Or did I misunderstand your question and it was more about politics? Chisinau then

[martin007]

No politics.
The question was about physical and social proximity.
Language, etc.

"Politics for politicians"

[fordragon88]

No politics.
The question was about physical and social proximity.
Language, etc.

"Politics for politicians"

Honestly, I've probably only spoken to people from Transnistria twice in my life. They're completely cut off from us. As for language, we speak Romanian at home. It's a local dialect, so to speak. I also speak Russian and Ukrainian.

[fordragon88]

I was considering switching to lithium (LifePO4). I found a local battery assembler, but he doesn't know how to properly connect the battery to my wheelchair. Could someone explain to me, for example, the Permobil F5, how to do this correctly?

[Burgerman]

If this battery assembler has any clue at all about what he is doing then how to fit a 24V battery to anything is OBVIOUS and simple. The fact that he says he doesent know how tells you all you need to know about him. Run away.

Theres 2 batteries connected in series. Like every 24V system in existence.
The only thing different to the drawing is that theres a simple breaker or fuse in that link between the two batts.


I suggest that you find someone else that is competant. Or DIY.

[shirley_hkg]

https://www.wheelchairdriver.com/board/ ... =2&t=12287

[fordragon88]

https://www.wheelchairdriver.com/board/viewtopic.php?f=2&t=12287

God bless you, there is so much useful information here, I've been reading all evening and it has all the answers I need.

[fordragon88]

If this battery assembler has any clue at all about what he is doing then how to fit a 24V battery to anything is OBVIOUS and simple. The fact that he says he doesent know how tells you all you need to know about him. Run away.

Theres 2 batteries connected in series. Like every 24V system in existence.
The only thing different to the drawing is that theres a simple breaker or fuse in that link between the two batts.


I suggest that you find someone else that is competant. Or DIY.

Fortunately, he refused himself.

[fordragon88]

https://www.wheelchairdriver.com/board/viewtopic.php?f=2&t=12287

I read the entire thread at the link. Now I have even more questions. How will it work without a BMS? And how do I charge it? I don't have a PL8 (I don't even know what this is ).

I thought that if I put together 8 3.2-volt cells and installed a 300-amp BMS with them, that would be enough.

[Burgerman]

As a bad way to do it then it is.
The difference is that a BMS does many things you dont want in a chair, like chopping off power completely every time it decides to... Which is dangerous to the control system, and you.
And they do a crap job of charging too...

But one of the bigget reasons is that in my own chair by way of example, I can fit those 230Ah super high quality cells that are really 244Ah. If I try and fit a huge BMS in there too then because that battery takes up all of the space, then I need to fit one that is 1 inch "shorter" in height. Now we are doen to 160Ah...

So the cells get a harder life which they dont like, charged more frequently so using up the now reduced cycle life, and if you leave a nice sensible reserve in use we get half the range.

Because those things are big.

A hobby charger, which the PL8 is, is discontinued. But others like icharger are also available. I use the PL8 because I like to configure it and watch the graphs, and fine tune it from my laptop while in bed...

Also remember that a battery with 6x the range, will need 6x the power level while recharging if you dont charge daily. And with lithium you shouldnt.
To return say 35Ah back to a lead battery meand 8A is fine and you get an almost complete charge in 5 hours.

If you want to put say 200Ah back that needs 40A from a hobby charger, for 5 hours! The PL8 is a 40A charger. Or whatever you decide it is. It also balances cells and charges at the correct voltages and terminates charge at the right point. A thing that a dumb BMS cant.

[Burgerman]

PL8...

Heres a couple...

With a charge/balance cable

https://www.wheelchairdriver.com/BM3-co ... DCABLE.jpg

Below, 3 on my bench...
With many many charge cables for all sorts of batteries from cameras, model plane stuff, AAs, you name it! They charge anything and everything...

Heres a charge graph... Showing all cells perfectly balanced as they charged.

It discharges too. So that you can set the correct parameters to test a battery. Here I am discharge testing a 75Ah lead AGM battery. Down to the specified voltage at the 20h rate. Its ending at 74.xAh so as new. In all its a useful tool. No more guesswork.

[Burgerman]

That PL8 charger is a 1340 watt charger. Or a 3 watt charger, from 1 cell, a watch battery or a AAA cell, to a 230Ah 24V chair pack, 5 different chemistries and a discharge capacity tester all at once!

It needs a 10 to 28V power supply. It can step UP voltage so that you can charge a 24V chair in a car... From 12V system. Or one chair from another at 40A if you need to. Or in my case my RC helis, from my chair at the flying site... So LiFe chair to LiPo 6S 25.6V for the helis. Flexibility is the key.

To power in in my home I use either a 30A 24V bench power supply, like in the previous pics, or a ZXD from shirley....

A picture of that is below... I have 2.

YOU dont have to do things the same way...

That can do 0 - 70V. 0-50A, 2 or 3 stage PROPER charging for lead, OR lithium with a BMS or just function as a power supply for testing or powering things like the PL8.

Its 3000 watt capable... So can charge a chair with large lithium as fast as your house can provide. Does your head hurt yet?

[fordragon88]

That PL8 charger is a 1340 watt charger. Or a 3 watt charger, from 1 cell, a watch battery or a AAA cell, to a 230Ah 24V chair pack, 5 different chemistries and a discharge capacity tester all at once!

It needs a 10 to 28V power supply. It can step UP voltage so that you can charge a 24V chair in a car... From 12V system. Or one chair from another at 40A if you need to. Or in my case my RC helis, from my chair at the flying site... So LiFe chair to LiPo 6S 25.6V for the helis. Flexibility is the key.

To power in in my home I use either a 30A 24V bench power supply, like in the previous pics, or a ZXD from shirley....

A picture of that is below... I have 2.

YOU dont have to do things the same way...

That can do 0 - 70V. 0-50A, 2 or 3 stage PROPER charging for lead, OR lithium with a BMS or just function as a power supply for testing or powering things like the PL8.

Its 3000 watt capable... So can charge a chair with large lithium as fast as your house can provide. Does your head hurt yet?

Honestly, my head is spinning a little. There's so much information out there. As someone who's very far from anything electrical, I thought it would all be a little simpler.