LiFePo Battery upgrade selection criteria (LiTime - Buyer Beware!)

What follows describes my purchase of 2 LiTime 230AH batteries, one of which was defective.   In a nutshell, while LiTime acknowledged that it had a well-understood defect, they would they would not provide a replacement without first receiving the defective one back, shipped at my expense.   The cost of freight ($635USD) exceeded the value of the battery, and they would not make an exception to their policy.  I was left with little choice but to buy and ship a second battery, risking a repeat of the same situation.  Thankfully the second battery worked (so far) and both are installed.  I again tried to revive and then scrapped the defectivc one.  

This was definitely a case where a low price had a high cost, and I will not deal with LiTime again.  Outside of the continental US there is effectively no warranty, even for a brand new battery that is DOA.  In the USA, the customer is still responsible to return the unit prior to (maybe) receiving a replacement.     

Prior Posts

Defective LiTime Battery

As discussed in the earlier post, (below) I purchased 2ea LiTime 230AH lithium batteries, and had them shipped to my my freight forwarder in Miami, and thence to Curacao.  

One of these turned out to be defective.  LiTime acknowledged this but was unwillng to replace it without first receiving the defective unit back, meaning it had to be shipped back to the USA at my expense. Shipping would cost $631USD to airfreight from Curacao. (the only option)   The battery currently sells for $614USD.

Given the cost involved in returning the defective battery, (I sent LiTime a copy of the quote) I asked them to simply ship the replacement to Miami, and I would pay (again) to ship to Curacao.  I did not ask them to do anything more than deliver a functioning battery to the same location in the USA as they had originally.  My ask was that they make an exception to their  ‘return of defective’ requirement, given the cost.   To me, this seems reasonable.     Fully aware of the situation they responded as follows:

This leaves me  the unenviable choice of:

•  taking a chance ordering a second battery from LiTime, potentially getting another defective one and being out of pocket for TWO. (and still needing to purchase batteries)
• buy and ship one from a better supplier to replace the defective LiTime unit, and use both, mixing battery/BMS systems. 
• scrapping both of the LiTime batteries and replacing with those from a more reputable supplier.  

LiTime chose to hide behind a policy rather than of taking ownership of an acknowledged product defect in a new, unused batgtery, choosing to let the customer bear the cost.     Buyer beware!

Nature of the defect -

 liTime explained to me that  batteries cannot be shipped fully charged.  Sometimes the battery’s voltage drops below a safe threshold, triggering the BMS’s protective mode.  The BMS can be reset by applying a brief overvoltage to the battery.  Once reset, it will accept a charge.  I walked through this with liTime via email to confirm the battery (the BMS actually) was in fact defective.  Bizzarely, the supplemental documentation states that “ 85% of the time” this over voltage reset method revives the battery.  This leaves me wondering about their actual failure rate.  

Batteries 

Sakura's house bank comprised 4ea 110AH group 31 AGM batteries, plus a fifth one for the engine.  The house bank would therefore offer approximately 220AH of usable capacity when new.  These batteries were 5 years old and required replacement, providing the opportunity to upgrade to LiFePo.. 

Which form factors best fit the 435/6?

The compartment is below the cockpit, accessible from either aft cabin, and measures 22.5" X 30.25"X 9.5" deep with limited clearance above. There is  room for additional batteries elsewhere should that be necessary.  

Typical house battery sizes by convention:

-Group 31 Batteries:    13 x 6 13/16 x 9 7/16 inches (~13 x 6.8 x 9.44 inches, 330 x 173 x 240 mm), 

- 4D batteries: 20 3/4 x 8 3/4 x 9 7/8 inches (527 x 222 x 250 mm),

- 6D batteries: 20 3/4 x 10 x 10 1/4 inches (527 x 254 x 260),

- 8D batteries: 20 3/4 x 11 1/8 x 9 7/8 inches (527 x 283 x 250 mm).

"We emphasize these 'maximum dimensions' since some of the BCI group 8D batteries are closer to group 6D or group 4D, but they are still labeled as 8D battery group and similar."

The BCI group sizes are very relevant for vehicles, but less so for off-grid applications where specific mounting methods and wiring configurations are not a consideration.   Thus, many larger form factor (4D and up, 20" in length)  drop-in LiFePo batterries are being produced that vary in dimensions and terminal styles.  One of the challenges involved is getting these larger sizes in and out of the 435's battery compartment is the limited clearance above.        

This challenege was addressed by cutting down the side of the box in Maria's  very large installation.    Impressive.    She also provided me battery compartment dimensions at 56x76x23 cm.     (22X30X9")   Thanks Maria!   

After some research, I purchased 2ea of the following as a first step.   At 230AH each this doubles the existing house bank capacity.