I just completed a lithium ion battery upgrade to my 2010 Duffy M160, and I thought I'd share my experience for those interested. My apologies in advance for the length of this post
The seller has been in business for just under a year. He has his shop in SE Michigan, and he assembles batteries from cells and components sourced from China. I talked with him a couple of times, and while he doesn’t have a long track record, he seems to know what he’s talking about, so I decided to take a chance. I purchased the battery (now appears to be out of stock) and his better 54.6V charger (also out of stock) so that I’d have a charger I was sure would work with the battery. He ships by UPS, so I received the battery and charger within a few days of ordering. This battery is about 9.5 inches wide, so while it fits very well on my boat in the battery compartment under the seat on the port side, I don’t think this would work for the V-hull boats that have batteries in line in the keel. More on that below.
Meanwhile, I sent my spare Delta Q charger with built in DC-DC converter off to a guy in Oregon who charges $50 (and it cost about $40 for round trip shipping) to reprogram the charger and replace the Flooded Lead Acid charging profiles with 9 different lithium ion charging profiles, one of which was perfect for this NMC battery. Once I got the Delta Q charger back, I connected it to the battery in my garage, where I confirmed that it charged the battery just fine. All the indicators on the charger and the dash LED work like they should, and the charger reduces current and stops charging in stepwise fashion. I’m very happy with the charger, especially since I didn’t have to wire in a separate DC-DC converter.
Once I had all the components, I installed the battery in the port side, along with a positive bus bar. I decided that I needed a good battery monitor, since I knew the Duffy gauge on the dash would be useless. So, I purchased and installed a Victron SmartShunt in the port battery compartment, which connects to the negative side in the battery and provides a lot of battery data by Bluetooth to my iPhone. I also installed a negative bus bar in the battery compartment on the starboard side, which was very convenient and prevented me from having to move wiring around. Finally, I swapped the FLA charger with the re-programmed charger.
Several sea trials have proven that everything is working to my satisfaction. When at cruise speed of about 4.3 MPH, the boat consumes about 40A, so with a 15% reserve, I’m getting somewhere around 3 ½ hours of run time, which is more than I got with the FLA batteries, so that meets one of my key requirements. All in, between the battery and charger, reprogramming the Delta Q charger, and various bits and pieces such as the Victron battery monitor, bus bars, cables, lugs, and lug crimper, I have about $2,500 invested in this. My only concern at all is how long this battery will last. The specs say 6,000 charging cycles, which would equate to something like 20 years of life, but I’m skeptical about that. The warranty is for 5 years, but since this guy has been in business for a short time, I’m not sure what that really means.
You’ll see some sandbags in the pictures. This battery weighs only 78 pounds, but I removed 496 pounds of FLA batteries, so the net reduction is 418 pounds. This made the boat ride about 5 inches higher in the water. The prop was still submerged, but barely, and I wondered if the prop cavitation would increase. So, I placed 4 50-pound sandbags on the boat, with two on each side. However, with the M160, it doesn’t seem to make much difference with handling or anything else, so I’m going to do some testing in the next few days to see how the boat handles without the sandbags. It may work just fine with the M160, but I imagine the V-hull boats will need some ballast in the keel with a similar battery conversion.
I believe these batteries would easily fit the V-hull boats with keel battery compartments. These batteries are sold by a Chinese supplier but shipped from a warehouse in Indiana. They have been in business since 2014 and are manufacturers of many different variations of lithium ion batteries. These are LifePO4 chemistry batteries, so they weigh 44 pounds each, which would mean less ballast for the V-hull boats. You can parallel up to 8 of them, which would greatly increase capacity, if needed. I corresponded with them directly and had finally settled on a price of $3,000 for 4 units (outside of Amazon) including shipping from Indiana. In the end, I purchased the Hi-Power battery because of price and the convenience of a one-piece battery.
I'm very happy with the results so far, and time will tell for longevity. I've attached some pictures of my installation. Should you have questions, feel free to ask, and I'll try to answer them.
If you've read this far, thanks for reading my lengthy post!