fixing wheelchair

This charger cost around 150.00 for my wheelchair. It appears to me it is a basic battery charger. Are there any cheaper alternatives? I was thinking a simple multilevel car charger would work. Any suggestions? Thank you

For example something like this. I would make a quick connect harness for it. http://www.walmart.com/ip/Schumacher-SpeedCharge-6-Amp-Battery-Charger/13005743

It being called a 3 stage charger leads me to believe that it is a smart charger with battery monitoring for ideal charging rates for different levels of discharge.  If you get some cheaper charger, you will spend more money on replacing batteries.

No - a 3-stage is for AGM batteries; they do not have the higher voltage stage (see BatteryFAQ). The Schumachers that Don'tSteal suggested seem ok and are about $35 to $45 thru Amazon. BUT is it a 24V battery (2x12V?) or 12V. The charger you posted says 24V.... The voltage needs to match the battery - usually not above ~14.4V for 12V & 28.8V for 24V. Otherwise the key is not to "over current" the battery. The usual rule is about 1/10th of their C20 capacity. EG - if a buggy battery is 60AH (C20), then a 6A charger. (3-stage of AGM; 4-stage if wet cells.) Check your battery size, or if possible check its specs & recommendations. (Or post its brand & model here, and if 2 in series etc.) If it's 2 series batteries, they should be matched (same type, batch, age etc). (Same for parallel unless in constant use or charge)) $150 for a 4A charger! It sounds like here - a captive market and often better tax rates for recreational pushbikes etc than "essential" wheel chairs etc.