Maxwell ULTRA31/1800 Group 31 Engine Starting Module ESM Battery 12V DC 1800 CCA

As always, time will tell the whole truth, but so far this has worked out perfectly. It is installed on an old F350 7.3L turbo-diesel and the engine now cranks over like a 6-cylinder gas engine! These older engines use mechanical fuel pumps and fuel-injector pumps, so they are extra difficult to start. This truck uses the separate ignition relay starter wiring method, so re-wiring from battery start to ESM start was quite easy. BCI Group-31 is technically too large for F550 and smaller trucks, but I always am able to force them in. Non the less, even group-31 AGM batteries don't last very long here in Phoenix.The truck now has one "Main Battery" + the ESM instead of two parralleled batteries. Now the main battery NEVER does any heavy lifting and gets charged individually so it should last much longer than the traditional parrallel wiring method. Like a LifePO battery, the ESM must be current limited charged so I do have concerns if the engine should ever have problems firing up and where to require multiple starting attempts, because the ESM does not store very much "current capacity" (Amp hours) in the capacitors. I suspect that it only stores enough energy to crank the engine 2-3 times and then will run out of power and have to be recharged either by the "main battery" over time, or by a separate shore charger over time. Jump starting CANNOT be done with the ESM wired to the starter!! Make sure that you understand this! You would have to remove the cable from terminal #3 and attach jumper cable to the starter cable. Yikes.Regarding other buyers problems with warranty claims: I called Maxwell and they confirmed that this product MUST be purchased from, Mack, Peterbuilt, Kenworth or Volvo in order to maintain product supply chain confirmation. I tried for days to reach one of those manufactuer retailers and NOT ONE would return my email or provide a retail outlet website for this product. I bought from Amazon and purchased the extended warranty hoping that I won't get screwed by that warranty if I should need a claim service.It is noteworth to point out that in theory this is a solid improvement in technology and moves older trucks into the 21st century. Over the road trucks have been using this technique for several years. Some newer small and hybrid cars are using similar ultra-capacitors too, so this is not some odd-ball or difficult to use system like Brown's Gas injection, etc.I'll try to do a followup in a year or so.

Bought this module & installed in January 2019, kept discharging randomly. I contacted Maxwell Tech Support, they sent me tests/checks to do all of which came out good. Tech guy says try warranty claim, they tell me since I bought it from Amazon they wouldn't cover it. So since it took me over 4 months to finally find out that the negative post was cracked & causing it to discharge it's too late to return it through Amazon. So now I have a $950 piece of plastic junk I can do nothing with! I don't recommend this product!!

surprised by how well it works on a 15L engine.

Works as advertised

I had the maxwell and 3 AGM deep cycle batteries set up less than a year ago in a semi. And during this time the system worked well, with never an issue starting the engine, even during cold weather. Next event is the semi sits for a week and the engine wont crank. The AGMs dropped to 5Vs and the esm isnt charged. There wasnt any elec drain that couldve caused this loss, chances are either a more complicated issue that means the setup has no business being in a semi or its a faulty/overly sensitive esm. I had better luck with the old heavy duty lead batteries which are lots less pricey. And Maxwell customer service? Try zero.

The media could not be loaded. I installed an esm in my Cascadia and after I got the wiring correct istopped having a problem with the thermal switch. Now the truck is waiting for an inframe so I installed it in my Coronado since I was having a battery drain problem. I run all my electronics cooler heater etc overnight and I don't worry about battery voltage, as seen in the video. If you don't need it, don't buy it but if you do it's the best investment.

Halfway through my 2nd winter with mine. Installed in a 2011 Peterbilt with a ISX Cummins engine. The only time it's failed to start is one time when my main batteries drained completely dead to the point where it wouldn't click the solenoid. As long as the solenoid engages, you get full cranking power from the starting module. Cranks the 15 liter diesel over faster than 4 batteries ever did. My truck is warming up as I write this. Outside temperature right now is 26 below zero. Cold does not affect the ultra capacitor the way it does batteries. The original reason I purchased the starting module was because I was always worried that my batteries would drain down too far to start my truck in the morning after a long night of running my bunk heater, fridge, etc.....Works great for that, but even if I didn't have that concern, it still outperforms traditional batteries.

Battery post broke off! Battery is barely 3 months old. No one at Maxwell has answered the phones.