Fortress Power

dfm379

I really like the Fortress E-Volt MAX battery but I am worried that it's just a cheap battery made overseas that won’t last very long. The reason I say this is that there are a lot of red flags in the Fortress Power Limited Warranty. Red Flag #1 - They are warranted for 10 years inside of the US and 5 years outside the US. I asked customer service why but was never provided with an explanation - they just ignored my question. Red Flag #2 - Their marketing brochure lists specifications of Warranty - 10 years and Life Cycles - 8,000 @ 80%DOD, but the battery is actually only warranted for 6,000 cycles @ 80%DOD. The brochure is misleading. Red Flag #3 - the warranty does not list a performance metric for the warranty period, i.e. retain 75% of original stated capacity after 6,000 cycles. I don’t see how this warranty covers anything but a dead cell since it does not specify how much of its original capacity will be retained during the warranty period.

Has anyone on this forum had their batteries for 5 years or more? If so can you tell me how much capacity loss you have encountered.

Has anyone on this forum had their batteries replaced under warranty by Fortress?

Graham Parkinson

Good Point - Why would anyone in Canada consider getting a battery from Fortress with only half the warranty???  I was thinking of getting a Fortress Battery versus a Discover battery, but this silly warranty policy and unclear warranty language isn't going to lead to me getting a Fortress Battery unless clarified.

Graham Parkinson

Well, I found the Fortress battery warranty policy buried on their webpages, under the warranty claim page ... 10 year warranty in both USA/Canada.  Only 5 years for marine installations or installations outside of USA/Canada. They indeed do not specify any user meaningful performance metric.   It's a pro-rated warranty.  Note that they don't state how it's prorated years or cycles - based on whatever is more favourable to them in each case?

The Fortress Power Lithium Ferrite Phosphate Batteries LFP-5/10, eFlex, and eVault (“Product(s)”) as supplied and distributed by Fortress Power, LLC, (“Fortress Power”) a Pennsylvania corporation, are warranted (the “Limited Warranty”) by Fortress Power, LLC against manufacturing defects in materials and workmanship. Within the United States and Canada coverage is on a prorated basis for a period of ten (10) years (“10 Year Limited Warranty Period”); or for 6,000 cycles, 80% DOD; or for 2000 cycles, 100% DOD; whichever comes first. Outside the United States and Canada coverage is for a period of (5) years (“5 Year Limited Warranty Period”); or 3,000 cycles, 80% DOD: or for 1000 cycles, 100% DOD; whichever comes first. All installations of Fortress Products worldwide on marine vessels or mobile vehicle applications are covered by the 5 Year Limited Warranty Period. To be eligible, all Fortress Products must be installed by a licensed professional using the Fortress Power Installation Manual and the Fortress Power Integration Guide (both available at www.fortresspower.com/resources) 

This warranty policy is open to mis-interpretation or dispute as they guarantee lifetime energy throughput at various cycle drawdowns (Depth of discharge DOD) levels of 80%, 90% and 100% - with dramatic drop in capacity at 100%DOD).  But they don't state how the cycle history is determined or how these projected capacities are related to the warranty. 

So if you draw the battery down once to DOD of 100% (i.e. in a capacity test) you automatically only get the lower level of guaranteed lifetime energy throughput??   Also, they don't specify how the warranty claim is evaluated - by internal logging?  There is no mention of guaranteed cycle capacity through the warranty period, only number of cycles vs DOD.   Also, must be installed by "licensed" professional, whatever that means (guy with a driver's license?).

Graham Parkinson

Lots of discussion about Fortress warranty on the DIY Solar Forum.  Summary is that Fortress has a warranty based on total lifetime power throughput as logged by their BMS and that they have been pretty good with tech support and battery replacement. 

Fortress plans to issue a clearer warranty statement soon.

Any Fortress users that can provide some insight into what the Fortress BMS logs? - Is all the logged information on DOD by cycle and total delivered power and other statistics available to the user?

Marc Kurth

I have always felt that battery warranty should be based on measured power provided. That just makes sense because that is the whole point.

Dave Angelini

A guy with a drivers license is not going to cut it if you want a warranty out 10 years. This is a high end battery and like a Tesla Powerwall the installation needs to be done correctly. Ask the store here what they think. I know it is evolving on this battery.

 In reality for offgrid this means you need to be up to speed on the install and have done your do diligence by taking installer webinars, learning the manuals, and making sure the system does not ever go down to the level where the power goes out.

The BMS logs Dod and Soc in and out and time stamped. Fortress can tell what one has done to the battery.

 If you really want the best out of this battery system, you should design for closed loop operation.

Closed loop is essential, in my opinion, in the cloudy PNW.  Also essential for long battery life. Closed loop also protects the battery from a user that may not understand, or has forgotten max charge and max discharge amps.