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Report on WalMart Maxx 29 Batteries

51K views 118 replies 22 participants last post by  Ziggythewiz 
#1 ·
Thought I would post an update on the Walmart Maxx 29's that I am using. I have 8 of them in a 2340 lb (total weight) car for 96 volts. Almost all of the mileage is about 10 miles total at any one time with a couple of times out to 20-22 miles. And yes I could go further.

Based on that type of use, I have recharged them about 40 times over the course of 2-3 months. I recharge them individually directly after each use, with a 6 amp charger.

So far they are doing just fine. In fact, they seem to have gotten stronger. That could be a result of cooler weather. They all still read within one tenth of a volt of each other.

Granted, this is not a long term test just yet, so I may wind up being disappointed as some have said about the Maxx 29's. But so far so good.
 
#3 ·
The batteries were $74 each for a total cost of $592. They weigh 65lbs each. Yes, that is the total weight of the car, batteries, all components, everything. 2,340 lbs. Fairly light for an EV conversion and still under the Max GVWR for the car so did not have to do any thing to the suspension.
 
#4 ·
I haven't finished my EV yet, but I have the MAXX29s. I am wondering if you have the Exide or Johnson Controls version of the Maxx29. While I haven't done anything more than drive up and down the driveway, I am pleased with them so far. I have individual 6 AMP chargers for each battery and they seem to charge them nicely.

What speed were those miles at? I am hoping for a 32 mile range at 40 MPH. But I am trying to get a charge at my destination and hope to take that down to 16-17 miles per charge.
 
#5 ·
Please keep us updated on your findings with these batteries. I'm considering them for my project. They're the same price as some golf cart batteries locally, but the Maxx batteries have a longer warranty. I'm very interested in how they hold up, and how the warranty goes if you should have any problems.
 
#6 ·
What speed were those miles at? I am hoping for a 32 mile range at 40 MPH. But I am trying to get a charge at my destination and hope to take that down to 16-17 miles per charge.

Most of it is around the 30-40 mph range with a couple of runs at 50-55 mph. I have twice run for better than 12 miles at 50-55 mph in 4th gear with no problem. I can readily go 25-30 miles at at 30-40 mph. I do drive easy and watch the amps closely.

You did not state what voltage or how many batteries you plan to use or how much weight your ev is. With my setup, I can easily go 16-17 miles and still have plenty left.

I was told that batteries like to be bulk charged. I personally do not believe that and these Maxx 29's respond well to individual charging as you plan to do. As I stated, they still read within one tenth of 1volt. So they are still well equalized.

Since the Maxx 29's are not true deep cycle, golf cart type batteries, I think that the best possible care for them will prevail for the long run.

Some folks have not been happy with these for EV use. All I can do is report my own experience with them and so far they are doing well.

I have the Exide version batteries but I doubt that there is little if any difference between the two versions.
 
#7 ·
I am having a 96 volt system like yours and an estimated 2500 lbs of EV. I seem to be the only person with the Johnson Controls Maxx29 version. So from your finds so far, my 32 mile range goal isn't impossible. And I do drive back roads and slowly. I also have a good 2 or 3 miles of drive that I am lucky if I get past 25 MPH due to inner city traffic.
 
#9 ·
I had to go to three Wally Worlds to get mine because none carried enough. I bought one for testing, and then went back two more times to different stores because one had two batteries and the other had the last 5 i needed. And damn, the back of our minivan was riding low.....:D
 
#10 ·
Nice post on using super Wally world's as a battery supply. Did you pay core cost too? I have been curious and wonder if you could by in quantity from Wal Mart, AutoZone, and PeP Boys? I did have a Maxx battery on my 1997 Ford Ranger and lasted about 4 1/2 years.


No, I did not pay core cost because I had 8 old batteries collected through the years. Yes, I bought all 8 at the same Wal-Mart and they still had one left.

I have to add some important info on my conversion that may be of some significance. I purchased tires that allow me to keep them at 50 psi and I use Amsoil sythetic oil in the gearbox. I do not have hills to contend with. Also, I have a small 12 volt battery for all accessories so they do not draw anything off the pack.

I am having a 96 volt system like yours and an estimated 2500 lbs of EV. I seem to be the only person with the Johnson Controls Maxx29 version. So from your finds so far, my 32 mile range goal isn't impossible. And I do drive back roads and slowly. I also have a good 2 or 3 miles of drive that I am lucky if I get past 25 MPH due to inner city traffic.

Well, with what you describe, I think you may be able to do it. Careful driving is important. Easy starts, coasting, and such.
 
#11 ·
It's not uncommon for a new pack to "get stronger" with a few cycles. These are called (by some) as the "break-in" cycles.

I can't explain it, but it takes a few cycles before they "optimize capacity"...

The true test of value for these batteries will be in the overall cycle life.

Traditionally, the cheap "marine deep cycle batteries" tend to die after just a couple hundred cycles at most... which of course means you'll end up paying 2-5 times as much to stay with that battery as you would to buy a "real deep cycle" traction battery to start with.

But, as with everything, YMMV.
 
#12 ·
Traditionally, the cheap "marine deep cycle batteries" tend to die after just a couple hundred cycles at most... which of course means you'll end up paying 2-5 times as much to stay with that battery as you would to buy a "real deep cycle" traction battery to start with.
quote]

That's what the 18 month free replacement is for. :D I plan on first babying them in their initial 20-30 cycles, and then give them some limited abuse and see how they take it. I went cheap because A) I could afford them and B) the warranty lets me beat the living crap out of them and not care. If Wally World asks, I have a really demanding boat.

If I can get 300 cycles out of them, that would give me about 2 years of battery life. I won't be hitting the highway, and I expect a 60-75 amp draw when cruising.
 
#14 ·
I jacked up my "free" replacement with the wally world "Max". Truck would not start and got a lift from a stranger who took me to AutoZone for swap
Anyway wally world, autozone, pep boys, and oreally all have or "say" limited lifetime on some of the batterys they sell. So like their top line battery will usually have a 3 to 5 year warranty period with doucumentation.!!!!!
So far in my limited search, the Maxx batteries 18month free replacement has been the longest warranty I could find for a "deep cycle" battery that was at a "standard" store. Many of the 3 - 5 year warranty batteries are standard starting batteries. I have one of the Auto-zone old top of the line starting batteries and it was a 3 year free replacement 5 year pro-rated.

I am considering the Maxx batteries based on the warranty as well. I won't be using the EV much, and the extra warranty should pay for the shorter life span. The way I see it, it's like a laptop warranty. If you're not getting the "free battery replacement" with a month or so left on the warranty, you're wasting a free battery. So, run the Maxx and replace them as the fail, and do your best to replace them all just before the warranty runs out. If they'll last 6 months without needing any replacement, that means you got a 2 year pack that was always almost new.
 
#15 ·
I have best experience with Oreally,Pep Boys, and Wal Mart. Autozone just wants to get you in and back out. The battery warranty and pro rate is nice. Pro rating the battery is a "gimmick" to make the battery sale. I am curious how good the wal mart motorcycle and jet ski batterys last?
 
#21 ·
The Maxx 29's are still doing well. As good as when I installed them and it has now been almost 7 months ago. I have them installed in a 84 X/19 Bertone/Fiat. Total weight of 2340 lbs using a LogiSystems controller. It is a 96 volt system with a Jim Husted motor. I think the verdict is still out as to real long term use on these batteries. But so far, I am satisfied. I have been getting about 20 miles range at 40-45 mph and have had the car to 65 mph.

After reading about failures on the LogiSystems controllers, I contacted LogiSystems and they said to send mine back for updates. However, I have not done that yet but probably will before the warranty runs out even though mine is working fine.
 
#22 ·
Hey all, just thought I'd drop my .02 worth in. After reading that the batteries are made by both exide and johnson controls I decided to ask my brother (who worked in automotive in walmart for some years) about them. He told me that our local walmart used to carry only johnson controls batteries and they were great. in more recent years our walmart has shifted to carrying exide batteries, which apparently are not so great. He told me that within six months he'd had more returns of faulty exide batteries than in the previous two years when only johnson controls batteries had been sold.

hope this helps
 
#24 ·
Yes. I can say that they did not fare well in cold weather. Range was cut to almost half in temps of the 40's or lower. Even temps in the 50's affected them considerably. However; once warmer weather appeared, the batteries seem to perform as they did previously. Quite well.

I finally sent the controller back to LogiSystems for the upgrade so have not been able to use the car lately. The controller was working fine but they requested I send it back for rework anyway. I must say that LogiSystems is easy to work with and they back their product. I believe they really do want satisfied customers.
 
#25 ·
So what is your official Range on your setup? Have you ever run them dead or is there still power left?

I haven't run mine into the ground yet and the furthest I have driven has been 10 miles in sub 40F weather. I have been using a PakTrakr, but didn't have it setup right until a few weeks ago, and the EV was already off the road for a motor upgrade. (Still waiting on it...)

I see you haven't made a garage entry yet, maybe you should because I am curious on your setup.
 
#26 ·
So what is your official Range on your setup? Have you ever run them dead or is there still power left?

I haven't run mine into the ground yet and the furthest I have driven has been 10 miles in sub 40F weather. I have been using a PakTrakr, but didn't have it setup right until a few weeks ago, and the EV was already off the road for a motor upgrade. (Still waiting on it...)

I see you haven't made a garage entry yet, maybe you should because I am curious on your setup.

The maximum range I have gone is 26 miles. That is mostly in the 35-40 mph range with a couple of miles at 50-55. The ambient air temperature was 80 degrees F. and the total resting voltage of the battery pack read a little better than 96 volts after the run. The chart I have equates that to about 50-55 percent SOC. Also, that was last summer when the batteries were fairly new.

A couple of weeks ago, with the ambient air right at 40 degrees F., I ran the car 16 miles and the batteries were at 86 volts which equates to something around 30 percent SOC. That is the first and last time I will take them that low. I simply made a mistake and took the car too far not realizing how much the colder temperature was depleting the batteries. So........I limped home and doubt that I could have gone another mile. However; I put a charge back on them and the batteries seem to be fine.

I do not have the PakTrakr. I have a digital gauge across the battery pack mounted in the dash and use that as a guide for SOC. I use a multimeter and keep tabs of each battery (not while driving) to make sure one is not misbehaving.

Sorry about not getting the car on the Garage entry board. I am not that computer savvy but will work on putting it in there.
 
#27 · (Edited)
I am using the Johnson Controls 12V marine batteries from Costco. Probably the same batteries. Got a pair for my Auranthetic at end of season for $49 each

A couple of things to watch out for are acid stratification and cell balance.

The stratification can lead to undercharging because it causes the voltage to read high so you and your charger are fooled. You can check this yourself with an electrolyte tester. Take some cell readings and a voltage reading and note them down. Then put the caps back on and tip the battery over a few times, tipping toward the terminals, to mix up the electrolyte, then take another reading. Voltage may drop and specific gravity may rise. If so, you had some stratification. Too much will cause undercharging and sulfation.

Cell balance. Check your electrolyte readings regularly both before and after discharging to check for low cells. I had one cell in a battery that went down to 50% while the others were still at 80% so my range was cut in half and I almost killed the battery. Now I'm trying to equalize it... still not there. I may kill it trying to save it.

None of my chargers have been fully charging my batteries so now I have been applying a soak charge manually. What a PITA. This makes buying a good charger worth it.

Good luck with your EV.
 
#28 ·
Just my update: I have over 500 miles on the MAXX29s in my Civic, and I had two go bad. Actually, they weren't getting fully charged and after many miles of driving the would get to 10.5 volts and 7.5 volts while the other were still at 11.2 under 150 AMP load, and 12.00v when letting off the pedal.

I have them replaced and now breaking them in. Used the smart charger and it gave them an equalization charge then normal charge for about 4 hours each at 2 AMPs before becoming "full".

It was not a fault of the batteries, but more fault of my K&W charger. The charging voltage was too low and would not charge them up all the way and that led to sulfation. I just never noticed until I pushed my EV to 16.5 miles, instead of the usual 14 miles. The PakTrakr started to flip out with a 12 volt battery now being 7.5 volts and I had to slow down from 40 MPH to 25 to keep the two in question about 10.5 volts under load.

The charger uses a small POT to change charging voltage and it gets moved around I guess. I have since fixed the problem, but just replaced the batteries instead of trying to work with them. 18 month free replacement came in handy.
 
#29 ·
I have better than a years worth of use on the WalMart Maxx 29's. None have failed and they have been recharged about 150 times. They are still performing o.k., although they do not seem to be as robust as they were but this may have nothing to do with the batteries. I have never had to add water to them and fully charged resting voltage on them are all within a couple tenths of a volt of each other.

They are usually charged at about 60-70% SOC and have once been taken to 30%. Most driving is less than 12 miles.

It may be a true statement to say that these batteries have been babied. The utilization of these batteries may not be representative of the average user. This is simply the way I have used them. All in all I am still satisfied with them but it still remains to be seem how well they will last into the out years. If I get 3-4 years on them, I will consider them a good value. However; I think I will replace them with the new lithium batteries once these quit.
 
#30 ·
What is your AMP draw when accelerating and cruising? I can now do 18.5 miles with little effort, but I try to limit cruising AMPs to 80 or less, and accelerate with less than 250 AMPs, usually 150 if possible. My performance isn't great, and I think it's all to do with my weeny controller just eating AMPs. The batteries usually read 95-96+ after letting off the pedal after the 18 miles.
 
#34 ·
I wonder how the wally world maxx29 compare to the AutoZone Duralast 24MD-DL. I currently have 4 of those in my golf cart that I just started using with the new batteries. I got them since they are only like a mile from my house I believe around $70 a battery. I however will be doing the extreme end and doing full throttle 400amp starts and really be punishing these things since its more of a toy then transportation. They are maintained well though so it will be interesting to see how they last.
 
#35 ·
Well the Duralast are made by Johnson Controls, who makes my MAXX29s and also 84betone's, so they should be similar in build quality, though the MAXX29 have more capacity and are a larger battery.

400 AMPs from floodies is pure murder on them. I am surprised they haven't popped on you.

I keep mine under 1600 at all possible, and never past 300 amps, and when I do I let off the pedal. I can't wait until I get my Synkro, then I will be able to limit the battery current to keep the abuse down to 250 AMPs or maybe even 225 AMPs depending on how it goes.
 
#37 ·
Just a quick update: The 60F and below temperature has really taken a toll on my range. So i whipped up a quick insulated box from 1" insulation foam board and duck tape. It did wonders for my drive today. My batteries have been at 63F and 58F for the past two morning drives, but today it was 81F and drove great. I probably could make it hotter if I timed my charging just right as the batteries were 92F last night with 10 AMPs going into them.

I also watered them, which took about an hour because the tops are easily accessible.

On another note, I have changed my controller order from a Synkro to a Zilla, so I should have that in the next month or so.
 
G
#38 ·
Wow, Jump directly to the Zilla. Might be what Synkro needs to be upgraded to. If the synkro were a 1k amp controller and sold as a beginning controller before upgrading to the zilla it would be good for the Synkro. I have been looking at all the different versions of the Zilla and what a mad house of decisions to make. This or that or this with that and maybe I should buy that just incase I decide I want more later.

Well, a good choice any way and you will be happy with the Zilla too. What version did you get? At least you will be in the 1k amp range now. Wooooo Hooooo. Glad to see Zilla back but not so glad because I spent money on the Synkro. I do like my Synkro but now the zilla is back................... I will talk with them.

Pete :)

PS. Have not been able to pull 700 amps yet from my controller. It is a nice controller and I give Synkro a full hardy thumbs up for an excellent controller.
 
#39 ·
I got the Zilla 1K-LV, and it's going to be a big jump from my 400 AMP Kelly, which really only puts out 180 AMPs when I need the power. I just have to make sure I don't abuse these MAXX29s too much.:D

I never thought I would ever get a Zilla due to the price, it was just a dream. However, an opportunity arouse and I took it last night to be on the list of the new batch from EV Components. Putting a Zilla in a 96 volt commuter EV that I only take to 35 MPH seems overkill at the moment, but then again I like overkill.
 
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