Battery question for fellow Magic Mobility V6 owners

[MenCallMeGimpy]

What batteries are you running in your chair?

I'm still using the ones that came with the chair when I bought it on eBay four years ago. Needless to say, they're a bit poorly now and range is down to about a mile. The joystick display is even throwing a "2" wrench-code when I use the elevate function, which I normally only see if the batteries are very low (very unhelpful code, BTW, since it basically translates to "something is broke"). This is now happening when they're fully charged.

So I'm resigned to buying a new set, but don't want to rely on whatever my DME needs to get rid of. I'm assuming the consensus is going to be MK, but which model specifically? Any other manufacturers/models worth considering?

Thanks!

[martin007]

Any other manufacturers/models worth considering?

Sonnenschein

[Scooterman]

Sonnenschein

I can never get the spelling of that right!

[sacharlie]

https://www.exmed.net/m-54-mk-battery.aspx

OR
A local DEKA dealer for a Dominator.

[Burgerman]

Or Odyssey PC1500, but those are a little longer than the grp34 spec says they are supposed to be so be careful. About 10mm extra. Only at the top. If they fit, then those are what I would go for.

In both cases, MK, or Odyssey (best), or sonnenschein dryfit gel, if you can find them, are all good. And to get the service life they all claim you MUST charge them correctly. Which rules out mobility chargers.

You could for double the price, get 5x the usable stored energy, (Same as buying 10x MK gels) with way faster charging, and at least a decade of service like, and around 4.5x to 5x the range. With around 180Ah of LiFePO4. Which obviously works out massively cheaper long term, even ignoring the x range increase. But requires some simple user knowledge and a fancy complicated charger.

[MenCallMeGimpy]

I'd love to go LiFEPO4, John, and had even started a project a couple of years ago, but my condition worsened to the point I no longer have the strength for it. I don't know anyone with the skills in my area, so I'm stuck in old-tech world for now.

I thought about Odysseys, but remembered the size issue and, since I can't get to the battery box to measure, don't really feel comfortable ordering them on faith.

I'll definitely check out the Sonnenscheins and MKs, though.

Thanks, everyone.

[Burgerman]

BOTH of those need a 28.2V CV charger. Preferably 12A.
Both need an 8 hour CV stage or 1000thC whichever comes first.

Which is all but impossible to find! Mostly because all chargers seem to claim to be able to charge all battery types, (they can, badly!) and never seem to give any sensible specs so you cant find out.

[Gnomatic]

I thought about Odysseys, but remembered the size issue and, since I can't get to the battery box to measure, don't really feel comfortable ordering them on faith.

Odysseys will not fit in a V6. Too long. As a fellow V6 owner who's had their chair taken apart for various reasons and done lots of measuring, I say that with confidence.

As far as chargers, consider the ZXD2400 from shirley. It can be set up with the correct charging parameters for your new gel batteries.

[Burgerman]

2nd ed. Set up correctly, it can do the right voltage 28.20V @ 20C, and 12A safe for XLR, And set for .1A or .2A termination, and float at 13.6V indefinite. Only thing wrong with it as a overnight charger is that its noisy. But doesent bother me. Others may be bothered!

[Gnomatic]

If it were to ONLY charge at 12A or fewer, might it be possible to just disable the fans without issue? I would think its substantial heatsinks would be enough for it to be passively cooled, similar to a silent standard mobility charger.

[Burgerman]

Wont start. It needs to see fans. Buy silent weak ones, fit those fan resister reducing connector cable extentions on ebay. Fit a couple if needed... The front fan is the one that bugs... The thing stays cold to the touch even at 50A. Fans dont speed up either on mine, grill removed, so plenty airflow. But I agree at 12A you may only need a single slow fan. A resistor may be able to replace the fan?

[martin007]

I'll definitely check out the Sonnenscheins and MKs, though.

Luck!

[LROBBINS]

Remember, you want MK GEL and NOT their AGM.

[Burgerman]

And anyone buying them, should read this very slowly!
http://www.wheelchairdriver.com/MK0.pdf

[MenCallMeGimpy]

Thanks for all the incredibly helpful info, everyone. I can always rely on this place for Total Information Immersion (I mean that in a good way!)

Gnomatic: "As far as chargers, consider the ZXD2400 from shirley." Thanks for this tip! I've started to read the fascinating thread on this, but I'm guessing I can't use Shirley's charger through the normal three-pin socket on the joystick pod? Looks like I'll need to wire Anderson clips directly to the batteries. Might be tricky given my lack of mobility, but I'll know more when I've read more. Also, thanks for the info on the Odyssey's being too big.

It looks like these are the ones I should be considering: http://www.ezmobilitybattery.com/mk-bat ... 4sldg.html Based on your experience with the V6, do these look right? The V6 user guide says 73ah, but I figured 74ah was close enough (since MK don't make a 73ah battery).

LROBBINS: "Remember, you want MK GEL and NOT their AGM" Got it!

John: Thanks for the info and the pdf. Looks like I need to study a bit. It's all going to hinge on whether I can figure out a way to add Anderson clips to my chair. If not, I may as well buy a pair of crappy batteries, since it sounds like even good ones will get wrecked by the charger IoM provided stock with the chair.

[Gnomatic]

Gnomatic: "As far as chargers, consider the ZXD2400 from shirley." Thanks for this tip! I've started to read the fascinating thread on this, but I'm guessing I can't use Shirley's charger through the normal three-pin socket on the joystick pod? Looks like I'll need to wire Anderson clips directly to the batteries.

No, you can certainly charge through the joystick pod @12A. BM made a video of the charger doing precisely that!

http://www.wheelchairdriver.com/gopro/3stage.mp4

It makes an excellent, versatile charger.

[Gnomatic]

It looks like these are the ones I should be considering: http://www.ezmobilitybattery.com/mk-bat ... 4sldg.html Based on your experience with the V6, do these look right? The V6 user guide says 73ah, but I figured 74ah was close enough (since MK don't make a 73ah battery).

Those are the right ones, though I would go with the flat top version of that battery for the V6.

http://www.ezmobilitybattery.com/mk-bat ... ldgft.html

[Burgerman]

Correct!

[MenCallMeGimpy]

Those are the right ones, though I would go with the flat top version of that battery for the V6.

http://www.ezmobilitybattery.com/mk-bat ... ldgft.html

Thanks! I was wondering if I needed flat tops.

[MenCallMeGimpy]

No, you can certainly charge through the joystick pod @12A. BM made a video of the charger doing precisely that!

http://www.wheelchairdriver.com/gopro/3stage.mp4

It makes an excellent, versatile charger.

Ooh, OK, so maybe I don't need to go the Anderson route. This is looking better by the minute. Thanks again!

[Burgerman]

It can do that. It will properly charge the MKs. If configured correctly. But its fan is loud, warning!, and it is really a 60V 50A capable 3kw power supply.

To get the best life from the MKs, requires both the right CV voltage, and the ability to set a low termination current. Typically it wont reach that low current overnight, and will be 12 to 14 hours. So fitting andersons, allows you to charge at say 25 to 30A which means the bulk of the charge loads faster. Lotsfaster in about 10 to 30 mins typically. Instead of 4 to 6 hours. So you reach CV faster. Giving more time to complete the charge more completely. Which means a longer lifespan. So yes it will do a 3 stage 12A correct voltages, float, too. With ONE CLICK once configured correctly which is a learning experience! But better to set double that Amp level, and use andersons if you can.

Full battery.
Set to 28.2V and 12A - FLASHES when turned on for several seconds.
Then displays the FLOAT voltage, and 0A until plugged in.
This allows you to be sure that the settings are still correct. You dont want to try and put 50A through the joystick

Then when plugged into chair it shows battery volts, and charge amps. Low amps here as its fully charged already. So as it drops fast and reaches my choosen 0.2A, the voltage then drops to the choosen 27.2V float. And amps start to read lower once battery voltage stabilises at the new lower voltage. http://www.wheelchairdriver.com/gopro/3stage.mp4

[Burgerman]

I think Martin007 wants one too but keeps getting ignored.

[steves1977uk]

I thought Martin007 had a ZXD2400 PSU from Shirley BM? I seem to remember him posting pics of it and asking how to set it up etc...

Steve

[Burgerman]

Maybe I am confused! Possibly elryko1992

[Gnomatic]

Shirley has set them up as three stage chargers w/ correct parameters for gel etc. before shipping them off to at least a couple members here. So the ZXD2400 can arrive ready to use as a mobility charger.

Stock fans are loud. But if you buy the ZXD2400 already installed in the fancy brushed aluminum case(now available!), its fairly easy to replace the stock fans with low rpm and thicker 25mm fans. Still moves plenty of air, and now quiet.

[LROBBINS]

Can you post a link or part number for the fans that you've found suitable? I have one of these power supplies in fancy case and it's really great, except for the loud fans. Strangely, in charger mode as current flow drops the fan speed does drop some until it goes to float, when the fan goes once again full tilt. Not the best programming.

[Gnomatic]

Can you post a link or part number for the fans that you've found suitable? I have one of these power supplies in fancy case and it's really great, except for the loud fans. Strangely, in charger mode as current flow drops the fan speed does drop some until it goes to float, when the fan goes once again full tilt. Not the best programming.

Yeah it spins up the fans when idling or very low current. Unnecessarily as its cold to the touch... Did you replace the mesh filter that comes with the fancy case kit? That thing is very restrictive. I used a chunk of speaker grill instead. The very loud stock 15mm fans are rated to draw .27A of current. I chose these 25mm thick Rosewill fans that are rated to draw .18A worth of current. They are more than sufficient to keep the unit cool, and quieter than stock for sure, although still audible when the PSU spins up the fans.(needlessly)

So on my second PSU I'm fitting a pair of these SilenX fans. 25mm thick and rated to draw only .05A worth of current. I haven't tried them yet, but my hunch is they'll keep the PSU cool enough while being all but silent.

BM mentioned something about using a resistor to trick the PSU to think a fan is connected, even though its not. Not sure how that works, but I do believe if only if only charging at low currents, the PSU would be fine to operate passively cooled as its one massive heatsink.

[LROBBINS]

The price for that SilenX fan at newegg in the U.S. is a quite reasonable $10.99m but their price here at newegg.it is E35.71 and Amazon.it wants E74.81!

[Gnomatic]

Those SilenX fans are $8.79 each if you order two or more here in the US. But super expensive in your location, yikes! Find some cheaper alternatives in your area, and look for fans with low current draw.

[Burgerman]

Thats because businesses and individuals are all taxed to death, and everyting we buy has to comply with endless EU "rules" which means armises or solicitors, paperwork etc. Thats what pays for the NHS and all the other gov handouts and projects. Its also why we pay about 7 dollars a gallon for fuel for a car.

The average price of a litre of fuel in the UK is now around £1.20 for petrol and £1.29 for diesel.

So 1.25 pounds per litre. Theres 3.8 litres to 1 US gallon, so 1.25 x 3.8 = 4.75 uk pounds, or according to google 6.20 US dollars a gallon. Plus about 500 a year insurance, and the same amount of tax for a large vehicle like these minivans. Sa add 1k to that on top.

In other words its growing socialism, and green socialism combined. 1/3rd of our houshold gas and electricity cost is because of green subsidies, and green power stations, costly windmills and abandoning coal etc.