Consequence(s) of using lower ah battery than recommended?

[Windmaker]

I have been the very fortunate recipient of a gift of a free electric wheelchair. Unfortunately the previous owner let it sit too long without recharging and some permanent damage occurred to the otherwise relatively new (2) batteries. They will no longer hold a very strong charge. The wheelchair is a Quickee G-424 (about 10 years old and manufactured by Sunrise Medical) and it's manual recommends that replacement batteries be of the following type: SLA, deep cycle, size 22NF or Grp 24, 12v, (minimum) 40 ah battery.

In researching the purchase costs of replacement batteries I've noticed that I can get a substantial cost savings from a 12v, 35ah SLA battery as compared to a 40-55ah battery. What specifically drew my attention is that the 35ah batteries are quite often advertised as replacements for 40ah+ batteries). In fact. the total cost difference can approach the $300 level. I'm not sure why that is, except that the 35ah types tend to be smaller in size, but my basic question is whether or not installing them would cause any harm to my wheelchair's motors or electrical system in general. I am aware that the wattage produced is equal to the voltage times the amperage, so there's no doubt that the 35ah batteries would probably result in some "underpowering"....but the real concern is whether or not this would have any harmful effects.

I am going to contact the manufacturer for their opinion on this matter, but I would also appreciate some disinterested opinions as well. With my being on a very small income the cost savings would be quite substantial for me if I could manage with the 35ah batteries.

Thanks for your consideration....

 

[amberwolf]

Given the cost difference and the size (and probable weight difference) the ones you want to use are probably not designed for the heavy usage typical of powerchairs, and probably won't last as long. (some have thicker plates and are heavier because of that, and they work at higher currents for longer).

Cost difference could also be if the source of the more expensive one is from a powerchair-specific supplier--from what I've seen they tend to overcharge for such things becuase insurance often pays for that sort of thing, and especially medical insurance seems to be geared towards wasting money like that and keeping prices high. Dunno if that's the case but it sure seems like it.


But if the only difference is capacity, according to the spec sheets (if you can get any for them), then the only worry about using smaller ones is you'll have less total range, and more voltage sag (less get up and go) under load, and the lower weight means less ballast to hold down the chair in turns or on slopes and when you're leaning over, so a little more care in those situations might be needed.

 

[teklektik]

No sure if it applies to you, but it may be possible to get replacement batteries under Medicare's Wheelchair and Scooter Benefit.

 

[dnmun]

if they are charging so much that just a few Ah is worth $300 then you should consider using a lithium ion rechargeable battery pack. i doubt if the weight is gonna be useful in any case and the lithium battery will provide longer service if you intend to use the battery for a long time.

 

[999zip999]

It also depends on your weight and how you use the chair. Flat or hills. You would need less performance for your battery pack.

 

[dnmun]

I have been the very fortunate recipient of a gift of a free electric wheelchair. Unfortunately the previous owner let it sit too long without recharging and some permanent damage occurred to the otherwise relatively new (2) batteries. They will no longer hold a very strong charge. The wheelchair is a Quickee G-424 (about 10 years old and manufactured by Sunrise Medical) and it's manual recommends that replacement batteries be of the following type: SLA, deep cycle, size 22NF or Grp 24, 12v, (minimum) 40 ah battery.

In researching the purchase costs of replacement batteries I've noticed that I can get a substantial cost savings from a 12v, 35ah SLA battery as compared to a 40-55ah battery. What specifically drew my attention is that the 35ah batteries are quite often advertised as replacements for 40ah+ batteries). In fact. the total cost difference can approach the $300 level. I'm not sure why that is, except that the 35ah types tend to be smaller in size, but my basic question is whether or not installing them would cause any harm to my wheelchair's motors or electrical system in general. I am aware that the wattage produced is equal to the voltage times the amperage, so there's no doubt that the 35ah batteries would probably result in some "underpowering"....but the real concern is whether or not this would have any harmful effects.

I am going to contact the manufacturer for their opinion on this matter, but I would also appreciate some disinterested opinions as well. With my being on a very small income the cost savings would be quite substantial for me if I could manage with the 35ah batteries.

Thanks for your consideration....

why did you ask? were you interested in our opinions or advice? do you know if the batteries you buy will be the capacity that they tell you that they are or do you think people who spend their time working with batteries might know more than the people who are desperate to sell you a battery that has been sitting on their shelf for 2 years?

 

[dogman dan]

The 35 ah cannot harm your motor or any other part of the chair. But an inadequate lead battery can fail quickly if the chair is used a lot.

The main things with lead are freshness, and the type and thickness of the plates inside. A car battery is much cheaper, because the lead is thin, but it just cannot power an Electric Vehicle for long.

So first and foremost, make sure whatever size you buy will be rated for wheelchair use. Even within that type, there will be cheaper ones with thinner plates. Thinner plates easy to spot, the battery will simply weigh less.

Then make sure cells you actually buy are not old ones sitting on a shelf a year or more.

For you, a much less expensive 35 ah battery might work fine. If you can charge more often, it will last fine. In home use of a power chair, you can charge twice a day fairly easy. But if you leave the home, and need it to work for a long time, then you will need the best lead you can find. Or lithium, but that's likely too expensive for your budget.

Definitely look into Medicare or Medicaid if you need that chair that bad. Even if you can't get help right away, chances are you do qualify. Get on it when you can.

 

[Windmaker]

To: amberwolf, teklektik, dnmun, 999zip999, dogman dan. & eTrike

I want to thank each of you who have taken the time to reply so far.....it is truly appreciated. Let me make a few points before I list some battery candidates I'm considering...

1. I think the costs outweigh the benefits for my personal case with respect to lithium batteries, but they are definitely worth consideration in all cases.

2. I'm pleased to to hear that apparently the lower amperage batteries will not harm the motor and/or system (even if I do weigh 300lbs), but I will apparently sacrifice power and longevity.
I am not yet what I would consider a "heavy user" of this wheel, just a "light user" for occasional trips within the community. At age 71 my leg condition deterioration is a progressive one,
however, so my needs and qualifications will continue to change also. Also, my pension income is just barely over the minimum needed to qualify for medicaid.

3. All of the 35ah batteries I'm considering are supposedly designed for electric wheelchairs.

4. My doctor is a VA physician and I don't know yet whether he's enrolled with Medicare or not (one of the Medicare requirements). I will certainly pursue that matter further...thank you.


Delivered prices from some candidate sources for (2) 12v 35ah batteries for wheelchairs

$86 (current bid) - ebay seller (no transaction history) note: @ battery weighs 23.15 lbs..(thin plates)
http://www.ebay.com/itm/2-QTY-12-Volt-35-Ah-UB12350-Wheelchair-Scooter-Batteries-/221823638462?pt=LH_DefaultDomain_0&hash=item33a5b81bbe#

$113 - ebay seller
http://www.ebay.com/itm/1-12V35-AH-SLA-BATTERY-FOR-WHEELCHAIR-MEDICAL-USES-SERVING-U-S-SINCE-1961-/331567185511?pt=LH_DefaultDomain_0&hash=item4d32f1be67#

$123 - ebay seller
http://www.ebay.com/itm/New-12V-35AH-U1-SLA-AGM-Battery-Scooter-Wheelchair-Replaces-UB12350-AGM1234T-/371373130253?pt=LH_DefaultDomain_0&hash=item567790420d

$127- Battery Sharks
http://www.batterysharks.com/Electric-Mobility-Lil-Viva-410-PC-p/410PC_B12-35_x1.htm?gclid=Cj0KEQjwoIitBRDTgeiZq93F2LQBEiQAMfXL0aK7YZgpPFh8BCUPp4NzuHfVlfMxKgIl0V2CySu79jwaAjOj8P8HAQ

$128 - ebay seller
http://www.ebay.com/itm/UPG-UB12350-12V-35Ah-Wheelchair-Medical-Mobility-Battery-/221400493473?pt=LH_DefaultDomain_0&hash=item338c7f6da1

 

[dnmun]

call around where you live and see if you can find a local source so shipping would be less.

if you install the battery yourself then you should mount the battery so that it is standing on end. you want the plates inside the battery to be stocked horizontally like pancakes. that will give you much longer cycle life.

these are sealed so they do not spill when standing on end as does the flooded lead acid battery but the stacking of the plates vertically keeps the plates from separating as the gasses are formed at the electrode to electrolyte interface and pushing them apart so they last longer.

the same rule holds for lithium prismatic pouches. i still think that long term the cheapest solution is to use a lifepo4 24V 25Ah battery pack.

i bet you can get one for about $300 from the sun-thing28 guy. or build it yourself from used ping packs like i do. that would be cheapest except the people here now only use HK lipo anymore so no more used ping packs show up for sale.

 

[Windmaker]

call around where you live and see if you can find a local source so shipping would be less.

if you install the battery yourself then you should mount the battery so that it is standing on end. you want the plates inside the battery to be stocked horizontally like pancakes. that will give you much longer cycle life.

these are sealed so they do not spill when standing on end as does the flooded lead acid battery but the stacking of the plates vertically keeps the plates from separating as the gasses are formed at the electrode to electrolyte interface and pushing them apart so they last longer.

the same rule holds for lithium prismatic pouches. i still think that long term the cheapest solution is to use a lifepo4 24V 25Ah battery pack.

i bet you can get one for about $300 from the sun-thing28 guy. or build it yourself from used ping packs like i do. that would be cheapest except the people here now only use HK lipo anymore so no more used ping packs show up for sale.

-Thanks for the tip on standing the battery on its end....never heard that.
-Sun-thing28 ebay seller does not have a battery posted with your specs (LifePO4 24v 25ah)
-Is the battery posted below like the one you describe above? If so, would my current 24v, 5ah charger work with it, or would it need a new type charger?

$250 dlvd - LIFEPO4 LFX Cell Technology Lithium Battery (24AH 12V EQ L3)

http://www.cruisercustomizing.com/exclusive-xtreme-rate-lifepo4-lfx-cell-technology-lithium-battery-24ah-12v-eq-l3/part/SHORAI-LFX24L3-BS12?utm_source=adwordsfroogle&utm_medium=cse&utm_campaign=adwordsfroogle&utm_content=87378&kpid=87378&gclid=Cj0KEQjwoIitBRDTgeiZq93F2LQBEiQAMfXL0ZTZHE8YhivE-jVRN-rzW5-qdyfvgMlZBz-4tVv3BjYaAtsZ8P8HAQ#Fitment

 

[999zip999]

As I said you battery needs will change on how you use the chair. Around the house or taking it to the store up a hill. 300lb does add to the battery you need. Where do you live ? This could make a difference.

 

[Windmaker]

As I said you battery needs will change on how you use the chair. Around the house or taking it to the store up a hill. 300lb does add to the battery you need. Where do you live ? This could make a difference.

As I stated in a previous post, I'm currently a relatively light user making occasional outdoor trips around the community, and I may ride to a nearby store once in a while. I live in a beach town (Lewes, Delaware) with mostly level terrain so the inclines are very minor around here. As my leg condition continues to deteriorate I'll be using the chair inside more. Thanks for your interest.

 

[999zip999]

When I buy sla I buy from AAA as they have real fresh batteries. Don't know if they have wheelchair use batteries, but there 2yr guarantee and they come to you. I have two wheelchairs to take batteries and motors out of. I will understand them better tomorrow night. He has a recycling yard. So it can be a candy store. 40 kids bikes, 35 adult bikes. So toasted.

 

[Windmaker]

I want to thank everyone for their replies and suggestions. I've decided to spend considerably more and purchase a 12v, 55ah, deep cycle, SLA gel battery (22NF size) for my powered wheelchair. I think they will serve me well for quite some time to come. Unless someone has further comments or questions for me I'll consider this my last post for this thread. Thanks again.

 

[Windmaker]

If you have the ability to get LiFePO4 batteries instead of SLA, you will be much better off. Many of us have experience with lead, but as the saying goes, lead is dead.
I wish you well in your future endeavors.

Actually I did contact a couple LifePO4 battery sellers and they told me their batteries were not suitable for power wheelchairs....just their batteries perhaps? Can you direct me to a LifePO4 that
is suited for wheelchair use?

 

[teklektik]

I am not yet what I would consider a "heavy user" of this wheel, just a "light user" for occasional trips within the community. At age 71 my leg condition deterioration is a progressive one,
however, so my needs and qualifications will continue to change also. Also, my pension income is just barely over the minimum needed to qualify for medicaid.

I referred to a Medicare, not Medicaid, benefit. You are entitled to Medicare benefits because you contributed. It does not sound as if you are sufficiently disabled to qualify for the 'Medicare Wheelchair & Scooter Benefit' but you may wish to investigate this regarding future developments. Here's a gov document.

 

[Windmaker]

I am not yet what I would consider a "heavy user" of this wheel, just a "light user" for occasional trips within the community. At age 71 my leg condition deterioration is a progressive one,
however, so my needs and qualifications will continue to change also. Also, my pension income is just barely over the minimum needed to qualify for medicaid.

I referred to a Medicare, not Medicaid, benefit. You are entitled to Medicare benefits because you contributed. It does not sound as if you are sufficiently disabled to qualify for the 'Medicare Wheelchair & Scooter Benefit' but you may wish to investigate this regarding future developments. Here's a gov document.

Sorry, my mistake. I am familiar with the Medicare benefit and you are correct about my not being currently eligible, but I am on the cusp and will get there in the near future. Thanks for your input.

 

[dnmun]

I want to thank everyone for their replies and suggestions. I've decided to spend considerably more and purchase a 12v, 55ah, deep cycle, SLA gel battery (22NF size) for my powered wheelchair. I think they will serve me well for quite some time to come. Unless someone has further comments or questions for me I'll consider this my last post for this thread. Thanks again.

stand them on their end when you install them. they will last a lot longer.

 

[Windmaker]

I want to thank everyone for their replies and suggestions. I've decided to spend considerably more and purchase a 12v, 55ah, deep cycle, SLA gel battery (22NF size) for my powered wheelchair. I think they will serve me well for quite some time to come. Unless someone has further comments or questions for me I'll consider this my last post for this thread. Thanks again.

stand them on their end when you install them. they will last a lot longer.

Yes, I was thoroughly impressed with that little piece of advice......never heard that one before........thanks again [I hope there's room to do that]

 

[Windmaker]

I want to thank everyone for their replies and suggestions. I've decided to spend considerably more and purchase a 12v, 55ah, deep cycle, SLA gel battery (22NF size) for my powered wheelchair. I think they will serve me well for quite some time to come. Unless someone has further comments or questions for me I'll consider this my last post for this thread. Thanks again.

stand them on their end when you install them. they will last a lot longer.

Yes, I was thoroughly impressed with that little piece of advice......never heard that one before........thanks again [I hope there's room to do that]