JS Alternators Reviews | Customer Testimonials
What Our Customers Are Saying
Real reviews from real customers across BBB, Google, and direct submissions. JS Alternators has been building custom high output alternators since 2013 — these are the people who trust us with their builds.
4.8 / 5 stars • Lifetime Warranty on every unit • Built in Greer, SC, USA
⭐⭐⭐⭐⭐ Verified 5-Star Reviews
"Great customer service and very helpful. Had to contact them several times because I was unsure of the install procedure and they called after my email and walked me through the process. Great product and awesome customer service."
"JS alts response time with technical help only took them 3 minutes on average or less to directly assist in the setup of my new alternator — 320AMP high idle unit with a LIFETIME warranty! They even helped me identify multiple hard issues dealing with a 6-pin to 3-pin setup. Over all I highly recommend JS alternators. With big three upgrade I'm at 15.09 volts everywhere constantly with power drawing huge beefy subs and car speakers! Love this setup."
"I was looking for an upgraded alternator for my vehicle. Most alternators I was coming across were about 240 amp, which to me just wasn't big enough. Then I came across JS Alternators and they happened to have a 400 amp alternator for my vehicle. After installation I did have a battery light on, but JS Alternators was able to determine that I needed a new plug with a sensor wire. They shipped the plug out to me free of charge, with instructions on how to set it up. After installation everything is perfect. The customer service is excellent."
"I purchased my Alternator and put it in the garage without close inspection, 4 months later I went to install this on my project Jeep and found shipping damage from months ago. I contacted JS Alternators to see if they would fix it for me and they insisted on paying shipping both ways and covered all repairs — even though I offered to pay and it was at no fault of theirs. Customer service like this needs to be recognized. They have all my future business."
"Ordered a 370 Amp alternator. The alternator at idle exceeded the hot amp rating of 190 amps — measuring 198 max amps. Brought RPM up to 2500, still at 14.8 VDC and it produced a max of 393 amps — 23 more amps than it is rated for hot. This vehicle is used 5 days a week to jump start light duty diesel vehicles. I had the alt cranking out max amperage at idle for as long as 45 min, no issues. Very happy with the product."
"Great product with awesome customer service. Was having an issue with not charging — they asked for pictures and when they got them they asked for the alternator back and installed a different regulator to fix the problem. I cannot thank them enough."
"Thank you JS Alternator for everything — great customer service. Chris stuck by me on this ride making sure I got the right alternator for my vehicle, answered every question I had. Chris is awesome, great customer service rep. I will be purchasing more equipment from JS Alternator for sure, and the alternator is awesome!"
"I ordered an alternator from here and it came faster than expected being I ordered it right before the 4th of July. Quality was top notch, looks great. Price with the Big 3 upgrade and a 250 amp was the same as the AutoZone 100 amp factory alternator — and everything is American made. These guys are great, highly recommended."
"I purchased a 320 amp alternator from this company. The shipping was EXTREMELY FAST!! I followed the instructions exactly how they said through a series of well detailed emails. Customer service is extremely fast in responding and very courteous. Their products are as described and have exceeded my expectations."
"I HAVE HAD 2 OF THE JS ALTERNATORS — NOT ONLY ARE THE PEOPLE GREAT, BUT THEY ARE PUTTING OUT A WONDERFUL PRODUCT. I WILL CONTINUE TO GIVE MY BUSINESS TO THIS COMPANY. HANDS DOWN WORTH THE MONEY."
Direct Customer Reviews
"This thing works GREAT!!! I'm glad I chose to do business with your company. Your PRODUCT is top notch and the same goes for your customer service! THANK YOU for all your help from getting me the right alternator to answering a few technical questions I had. KEEP UP THE AWESOME WORK!"
"Outstanding — high quality, high amperage alternators with equally impressive warranty and customer service. I have no reason to look elsewhere. JS for the Win!"
"I have ran JS Alts for 4 years, they are very dependable strong alternators! I've broken several world records and won several world championships with them! Customer service is excellent also!"
"JS has been great!! They deliver fast build time, quick shipping, and great customer service. I will be a lifelong JS customer, that's for sure!"
"I have been using JS Alternators for 5 years now and have never had a company that stands so firm behind their product. I will also add that I never had an alternator fail on me in all 5 years of using their product. The owner stands behind his product and is a true professional when dealing with him."
"Awesome product. Keeps my voltage on point. I recommend to everyone to buy with JS. Also has great customer service!"
"JS Alternators has great customer service. Any questions I have about wiring they answer in a quick and timely fashion. I run their alternators in my daily vehicles and competition vehicles!"
"Customer Service is TOP NOTCH! Great company to deal with — if you're looking for a high power alternator, look no further!"
"Best price, best customer service, best product. It's a WIN, WIN, WIN all the way around!"
"Your best bet for high performance and top quality alternators!"
"You guys have the best alternators I have ever used! I'm pumped, I just got my second alternator in the mail today. JS Alternators are the real deal people! Fast service, too!"
"My car's lights no longer dim and over 3,000 watts in the system — it's fantastic! I'm just honestly grateful for such spectacular service and products. Thanks JS Alternators."
"Fantastic service, I must say! Awesome power at quite an affordable cost! I will be buying again!"
"I got an alternator from JS Alternators for my Nissan — since then my sound system is pumping, there is more consistency to my operation and I have you guys to thank for that. I'm blown away by their awesome service too! I recommend JS Alternators anytime, any day!"
"I normally don't bother leaving feedback on goods purchased but I have to make an exception. I ordered a 240 amp alternator sometime last year. My voltage has been steady above 14 volts since upgrading. It is one of the best improvements I have done for my car."
"I recently installed two of your 320 amp alternators on my Tahoe and a 240 amp on my Toyota. It's amazing the clear cut power difference I've observed! Thank you for your hard work and quality products! I'm sold and highly recommend your product!"
"Wouldn't go any other route in my builds. Great customer service to match a great product!"
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