Brian,
The EV guys have been doing a lot of work with Li batteries, their weight, available DoD and resistance to Peukert losses at high amp loads have convinced a number of them to convert.
Two of the promising vendors for LiFePO4 batteries are Evolve Electrics http://www.evolveelectrics.com/ in Colorado and Current EV Tech http://www.currentevtech.com/ in Washington. I've bought a charger and instrumentation from Evolve, but have no other interest in either company. These guys seem to have good prices for their product. Be sure to get quotes that include import duties (if any) and shipping charges to your door, that can sometimes be a surprise.
Current EV Tech has a number of BMS solutions, their owner developed the Mini-BMS and they sell the EV Power BMS from Australia. My Thundersky pack is protected by EV Power modules that I bought directly from Australia before they had a US distributor. Both the Mini-BMS and the EV Power modules are a cost effective way to add basic under-current and over-current protection to your Li battery investment.
The charger that I bought is an Elcon PFC2000+ because if its efficiency, thoughput and price. At their facility in Sacramento, Elcon will load a charging profile that is specifically tailored to your battery pack configuration. Manzanita makes chargers that are just as efficient and are user programmable, but are 3-4 times more expensive. I'll live with the factory firmware of the Elcon.
I doubt that $4k of Li batteries (around 10kWh) will provide an 80 mile range (125Wh/mile) at anything above 2kts. Can you provide some load estimates (in amps) from your boat at various speeds like 3, 4 and/or 5 kts? Given your observed amp load, I can run the Peukert calculations to predict ranges for various size battery banks. Given that 80 miles at 4kts would take 20 hours, you're looking directly at most battery ratings and Peukert tolerance of advanced battery types will not be a factor. On the other hand, weight and battery volume probably will be.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@yahoogroups.com, "drmsudo" <drmsudo@...> wrote:
>
> I changed over my Ericson 27 Atomic 4 to electric propulsion three seasons ago. I have been running it on 4 group 27 92ah deka batteries. This has worked well for day sailing. But, we would like to start cruising and I would like to have a range that could take us across Lake Michigan (about 80 miles). Most of the time we are sailing, but I want the confidence that we could go the distance if needed. I am thinking of using a Lifepo4 batteries from a company called HiPower (http://www.evequipmentsupply.com). The cost of the batteries alone would run about 4k, then I would need a BMS and charger to complete the system. The main reasons for the Lithium batteries would be weight savings, ability to deeply discharge without damage to batteries, and the number of cycles (2k) that can be charged. Anyone have suggestions or experience with the LiFePo4 systems? Other sources for batteries and how to build? I did the conversion myself, but I have no other experience with DC systems. Any input would be helpful. Thanks.
> Brian
>
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