Batteries for the Quickie Q700

[Ironside]

Can somebody point me direction where I can get some spare batteries for my Quickie power wheelchair. I'm looking for best price but without compromising quality. Thanks in advance

[Burgerman]

Ah. Well thats the problem.

best price but without compromising quality.

[Ironside]

Problem???

[rover220]

Mkgrp 24, or mk grp34 if you have Dahl fitted.

[Burgerman]

best price but without compromising quality.

The PROBLEM is that a powerchair, esp a heavy one like yours, absolutely murders any lead battery .Even the best ones. And the best ones are not "quality" enough. Anything cheaper will not perform as well, and not last as long. The problem is that theres very few good lead batteries. Basically you need MK Gel of the largest size that you can fit. And as Rover says, thats the 60Ah GRP34 MK Gel if you have the dahl locking system. And the much better GRP24 73.6Ah MK Gel battery if you dont.

There are cheaper options. Such as the 80Ah (no they wont give more range!) cheapies, like these GRP24s https://mobiquip.co.uk/strident-75ah-12v-battery/

They are half the price of a set of MK Gel batteries. And not as good. The problem with lead batteries is that you do get what you pay for generally.

[Burgerman]

For e.g. The batteries linked above.

They have:
Internal Resistance: Fully Charged battery 77o F (25o C) 5.7mOhms which means huge voltage drop under a load like curb climbing or trying to steer or zero turn. So this shows up as a lack of torque (inadequate power). And your chair needs that. Some cheap batteries are 8 to 10mOhm!

In comparison, the Odyssey smaller 68Ah battery by way of example, as I used to use these is only 2.5mOhms. So can deliver almost two and a half times more current at the same voltage drop when under a load. And the MK gel is 3.5 to 4mOhm. So also much better than the cheap battery.

The Odyssey can deliver 1500A for 5 seconds. Compared to 700 for the cheap battery. Because odyssey has half the resistance. This means the cheaper strident charges much slower too. The odyssey takes a full charge in around 10 to 12 hours. The cheap Strident battery takes 20 hours plus.

And importantly the MK gel offers 500 to 550 cycles if discharged down to the last 20%. (An 80% DOD). The strident cheaper battery can do 300 cycles at 80% discharge. So half as good as the MK in cycle life.

As I say. You tend to get exactly what you pay for with lead.

[Ironside]

Oh, I didn't realise that the Dahl wheelchair restraint use the wheelchair batteries.

I don't use my wheelchair for long distances. If I go into town, then I will drive and park somewhere. The longest distance I would travel in my wheelchair would be a matter of 500 yards when I go fishing. I don't really do any heavy duty trundling any more. Okay, there may be occasions when I will travel into town and the road leading back up to where I live is fairly steep. But I'm certainly not going to be doing that journey on a regular basis. This

[Burgerman]

The dahl system takes up space in the battery compartment. Meaning lower GRP34 batts are all that fit.

[Ironside]

The dahl system takes up space in the battery compartment. Meaning lower GRP34 batts are all that fit.

Blimey, I didn't realise that. That means I must have had the smaller batteries in the wheelchair when I first bought it? I will have to see if I can find the specifications for what I ordered, because I'm sure I went for the higher spec batteries.

[Ironside]

Is this the Dahl that you are referring to?

This is what I have in my van.

[rover220]

Is this the Dahl that you are referring to?

This is what I have in my van.

yes thats dahl.

[rover220]

i could be wrong with the smaller battery requirment mind, looking at the order form is does not say you can't have the bigger batteries with dahl but i do have a recollection of it.

[Ironside]

I can't find the order form. It must be somewhere in an email, but I just can't find it.

I'm finding that even though the battery indicator is showing a full charge for most of the day. When I get to early evening. The indicator suddenly starts dropping away. I did wonder whether it was a problem with the battery charger. So I've been charging the chair using a different charger, but it doesn't seem to have made any difference. What's annoying is the chair is barely 2 years old. So really, the batteries should still be good since I've not use the wheelchair extensively outside. I'm wondering whether maybe one of the batteries is faulty. Is there are easy way to check the batteries for faults?

What is really annoying is recently the backrest actuator failed and the backrest collapsed on me. I can only thank God that I wasn't driving at the time. Anyway, Sunrise medical Replaced the actuator under warranty. I mentioned the batteries but they won't replace them. As far as I'm concerned they shouldn't have Gone wrong so quickly.

[Burgerman]

I can't find the order form. It must be somewhere in an email, but I just can't find it.

I'm finding that even though the battery indicator is showing a full charge for most of the day. When I get to early evening. The indicator suddenly starts dropping away. I did wonder whether it was a problem with the battery charger. So I've been charging the chair using a different charger, but it doesn't seem to have made any difference. What's annoying is the chair is barely 2 years old. So really, the batteries should still be good since I've not use the wheelchair extensively outside. I'm wondering whether maybe one of the batteries is faulty. Is there are easy way to check the batteries for faults?

You seem to underestimate the loads that you put on batteries and their actual capability. If the batteries lasted 2 years used indoors which takes just as much out of them with the turning etc as a long run outdoors then they did very well.

A GOOD high quality set of MK batteries in your 185KG ?? chair will do extremely well to survive 18 months. I suspect that if you were to test those batteries with the PL8 chargers many of us here use, they will be down to around 2/3rds of the original capacity. So if 60Ah to begin with, will now measure only 40...

Remember its even worse if you have the smaller 60Ah batteries because of the lockdown systems brackets. Those batteries will be punished much more as you will be discharging them deeper every single day. Which degrades them way faster. And the faster they deteriorate the greater you discharge them per day... A perfect storm.

A lead battery, even the best, cant cope with heavy traction deep cycle use which is what we do. The very best like MK gel (and sunrise no longer fit those because of £££) will give you 500 cycles or 'days' if discharged to 80 percent depth. But only around 150 to 200 (8 months) if cycled deeper. If you only discharge them to say 50% max, you would get maybe 1000 cycles. Thats around 3 years. This is only if you charge them PROPERLY which mobility chargers do not do!

I think 2 years from a set of relatively cheap AGM deep cycle batteries is then pretty much better than I would have expected.




Of course the only way to know if its all in your mind, or if they really are down by 5% or 50% is to measure actual capacity at the 10 or 20 hour rate. Like this:

These are the 75Ah batteries that they fitted to my new Q700 chair. They are new. And the actual MEASURED ah capacity is almost exactly 74Ah or 74,023mAh. With no PL8 its impossible to know without guessing. Remember battery capacity doesent just suddenly "go", batteries dont fail suddenly in normal use, it diminishes slightly day on day from the month after you got the chair. Until you notice.

I would say budget for new batteries every 9 to 12 months if you buy cheap ones.
And budget for 14 to 18 months if you use good batteries. All depends on usage, battery size, charger capability etc.

This pain in the ass battery thing, with heavy modern chairs is EXACTLY why many here went lithium. Costs double. Or less. Gives 5x the range. And gives at least a decade if not longer of "range no problem"... Even if range HALVED, you could still go 2.5 times as far as a new set of lead bricks! And it charges faster and weighs less.