T-Pain Is On A Boat: RE: [Electric Boats] LiFePO4 Battery Pack

Tuesday, August 25, 2020

RE: [Electric Boats] LiFePO4 Battery Pack

Update: Thanks for all the replies to my message below. I just ordered four batteries from Battleborn. They should arrive in a week or so. The cost is 60% higher than the product I attempted to buy back in May, but I feel more comfortable buying from a well-known source. I'll report back here if there are any surprises – good or bad.

Thanks,
Pat

On Friday, August 21, 2020, 12:12:08 PM CDT, forums@greensdomain.com [electricboats] <electricboats@yahoogroups.com> wrote:
Hello Everyone,
Back near the end of April, I posted a question about my 10 year old AGM batteries that were showing signs of their age. (The motor is a Torqeedo Cruise 4.0R and the boat is a 24' pontoon used on small inland lakes). I received many useful responses and decided to order a 16-cell LiFoPO4 pack from a supplier on Amazon. At order time, the delivery date was scheduled for mid-June. When that time approached, I received an email saying they were delayed and wouldn't ship until July 5^th.. The next email said July 22^nd. Then August 4^th. I ended up cancelling the order (even though they said they would ship August 10^th to the 14^th. I told them to let me know when they were ready to ship and I would promptly place a new order... Well, here we are on August 21^st and I haven't heard a thing. On Amazon, it says new orders would be delivered in September. At least I haven't lost any money as my credit card was never charged other than a temporary hold being placed on the card which expired a few weeks later.

I was hoping someone on this group could provide a trusted supplier where I could order what I want and actually expect to receive it before the snow flies!
Here's what (I think) I want:
-A LiFepo4 battery pack to be used with my 48 volt motor
-Approximately 100 Ah capacity
-Some way to monitor charge level (e.g., a BMS with a Bluetooth connection to a smart phone, or some sort of a "Gas Gauge" display or meter)
-A built in BMS that protects the cells from undercharge, overcharge, and unbalanced cells.

I recently looked at Torqeedo's offering.. At around $5,200 USD (plus some "required" accessories and shipping), it is the most expensive pack I have seen, but it also confused me. Most of the packs I have looked at seem to use 16 cells so the nominal voltage is around 52v, but the Torqeedo pack says its nominal voltage is 44..4v and the low voltage cutoff is 36v. Can anyone explain why they would do that? Should I be worrying that a 16-cell LiFePO4 pack will damage my Cruise 4.0R?

Thanks,
Pat