http://www.radicalmobility.com/ - Gazelle 250 S (RWD)

[CPguy]

I am currently in touch with http://www.radicalmobility.com/ of South Africa as they seem to have chairs with wide tubeless tires, etc.

Of course, the (lead) battery capacity is a joke (35 Amp/h !) as are their weak controlers but aside from that they seem useable. Drive wheels (145/70-6) and casters (285/85-4) seem close to Burgermans' tires, am I right? (I plan on fitting Headway cells.)

I contacted the HQs but they are slow in replying to e-mails. Has anyone dealt with them before?

[Burgerman]

I see a great lack of detailed specs. But they seem to have fitted small batteries and fat tyres and ended up with wide ish chairs? Just over 27 inches wide. Hard to know from those pics. They have fitted small "half sized" batteries to allow this.

If you are not bothered about it being wide then you can fit those fat wheels and tyres to any powerchair.

And if you choose one with 70Ah batteries. Then you can easily fit 108Ah of headway cells or similar. I don't think you will get more than 40Ah of headway cells in place of 35Ah batteries.

Why doesn't it occur to them, or any manufacturer, to use bigger full sized group 24 batteries and turn them north/south as I have?

[Sully]

Quote "Why doesn't it occur to them, or any manufacturer, to use bigger full sized group 24 batteries and turn them north/south as I have?

This is the question for all time. Perhaps they spend their time going East/West and never heading towards their goal.

[Jamest]

The UK distributor for Radical Mobility is A4W Products, same as the Observer 4x4 chairs, they have already fitted the Observer with a 100ah lithium battery, so I'm guessing they will do the same with these one's. Nice bunch of guys, gave me a home demo for the RX. Might phone and ask for another demo for the Standing Predator 4x4, if you go on their website, you can download the brochures. Will definitely ask about lithium battery.

[Burgerman]

Just be sure it doesn't use a generic BMS... Or it WILL die.

http://www.wheelchairdriver.com/BMS.htm
http://www.wheelchairdriver.com/BMS-lithium.htm
http://www.electric-cars-are-for-girls. ... stems.html

[Jamest]

looks total gibberish to me

[Burgerman]

Then what will happen is this.

You will buy a 100Ah lithium conversion. You will gain 50 percent of the performance your lithium battery would actually have been capable of if it had been properly implemented. So instead of also going 2x as fast, you only gain range. And less than was actually possible. Ignoring this:

The BMS will cause your overpriced super expensive battery to live anything between a few weeks and a year or two. If it doesn't fail and leave you stranded for no apparent reason on a regular basis, or cause charging balance issues. Or a fire.

A BMS is a way of selling lithium batteries to the ignorant, instead of properly implementing it as part of a system. By ignorant I meant the observer designers.

[Jamest]

I contacted the distributor for observer and they said it was the lifepo4. Is that good?

[Burgerman]

It depends...

If its a BIG ENOUGH pack, and if it uses high C rate cells, and if it doesn't have some cheap Chinese generic BMS built in then YES. But likely it will not be any of the above, and will give a short life...

Details matter here.