EPU

Hi Scottie...
What is an EPU compared to the APU?
I have never heard the term before.

 

From my own research, it appears that an EPU is just an electric APU that draws power from the tractor's electrical system

 

Exactly it is Electric power unit. I have one and it has 3 deep cycle batteries mounted behind sleeper between the frame rails.

 

Does that mean 4 batts for the truck plus 3 for equ? 7 in total for the alternator to charge?

 

My problem with the electric apus at least as an O/O is that they tend to chew through batterys especially in winter or summer when the charge is affected by temps and how hard the Eapu needs to work to keep you cool or warm. This results in both less charge from the batterys due to outside temp (can be mitigated by a CCed or under bunk battery setup) and using more power to do the same job resulting in more charge cycles and lower battery life or even damage on some battery types.

This is further exasperated if you have an inverter and decide to use electric products. Not unusual for an Eapu truck to only get 3 to 5 hours if someone has a lot of electronics going like say a TV, sat dish, laptop, gameing system, fridge ect. These use a lot of power and can greatly shorten your charge time.

Batterys are expensive and while you dont need an oil change every 3 months with an Eapu, the all at once cost of batterys can be a hard pill to swallow as opposed to the spread out cost of diesel maintaince. Added to this is bad batterys means no EAPU means lots of idle. A diesel APU can go quite a ways past a scheculed maintaince before damage occurs and can buy you time in a pinch....say after a major repair or a lot of down time. Though diesel APUs have more failure points.

There is also the whole lithium fire thing as a posible outcome if you go that route. So cost is a wash either because you spent a ton extra up front for better batterys or because you replace them once or twice a year which offsets any fuel savings or APU maintaince and repairs.

There is also the fact a breakdown can leave you in dangerious conditions without heating or cooling. Idealy this would never come up but anyone who owns a truck can tell you it eventually will and you could spend as much as a day waiting on a wrecker. Or if you are an O/O it can remove the option of skipping a hotel. No one is going to willingly sleep in a truck that gets up over 100 or down below 0. A diesel APU will work even if your truck borks. Electric.....not so much. Again not a common thing but something to factor in.

On the flip side Eapus do tend to work more consistantly and have less parts to go bad overall. They also are quiet and dont stink either. And once def comes into play i agree they will be a superior overall option because def=death to anything mechanical. For the moment though because of the above i would say diesel APUs are slightly better then Eapus overall.

To be clear im not saying Eapus are bad just not as good a choice as diesel from an O/O standpoint. For a fleet a lot of these considerations just dont apply as they have advantages someone like me with 1 truck does not.

 

Tri Pac for the win.

 

EPU is definitely the future.Thermo king already had the optional Dpf for the tripac and it was a disaster which is usually the case with Dpf.

 

My truck had the idle free epu on it when I bought it , it did every thing so so but nothing well .
Parts were very expensive also.
Then one night it developed a dead short and pretty much melted the unit .
Threw it in the scrap pile and replaced it with a diesel carrier ....not perfect but much happier.