LiFePO4

[Island Time 1,235]

Mostly TAO BMS units. The std display does audio and visual, and there are 6 relays std, more of you wish. Despite the name, its a European company with a French electronics engineer designer/owner who is a sailor - currently in NZ, on his boat called Tao.

They currently have restricted supply though....

[Ladyhawk 37]

Yup I built our system with CALB cells and a Tao BMS. We also have HVC/LVC contactors that can be remote manually operated if needed.

TaoBMS is an awesome unit

[Adrianp 120]

I built my system using Winston Cells and the REC BMS that talks to the Victron Cerbo GX, MMPT and Inverter. 

It's been in the boat 2.5 years now, done the usual Xmas cruises, a 6 month trip to the islands and the we often run a dehumidifier off the inverter while sitting on the mooring so the batteries haven't had an easy run. They have just dropped from 99% State of Health to 98%, so it seams they have a long life ahead of them! 

Doing the design and install myself has been the scariest boat project I've ever done as there is so much info to wade through and so many ways to do the same job. 

For us in a cat, the weight saving is awesome. We replaced 400kg of AGMs and Generator with 120kg of LiFEPo4, heavy duty cables, inverter, MMPTs, B2B chargers, etc. We now have double the battery capacity and can go for days without running an engine.  

 

[DrWatson 375]

I'd really like to see the statistics for LiFePO4 vs AGM wrt to fires.
There's so much institutionalised fear in the bureaucracies that it appears to sneak often needlessly into our everyday lives. 

Our system was installed professionally by the manufacturer of the boat. There is not absolute disconnect. One has to unbolt the terminals to achieve that. An alarm sounds when the SOC goes below 30%, and the BMS turns the battery off before it hits rock bottom. I'm happy with it, EU marinas are happy with it, and our insurer is happy with it.

[Frank 157]

On 20/03/2023 at 9:06 PM, Island Time said:

Actually those anderson connectors are not that great for LifePo4. Think about this - only 2 of the 18650 cells (3,2v, look like torch batteries) that are in most of the drop ins, shorted, can produce 75a! Short out one 100a/hr LifePo4 battery can produce up to about 20,000 amps. This will blow a fuse of course, BUT, unless it's a class T fuse, it will then arc across the terminals and current will still flow.... So, proper install needs Class T fuse - for each battery - and battery isolation switches. To meet the NZ regs you need a system that gives visual and audio alarms before it shuts off the battery. You can't do that with a bluetooth BMS - It needs CAN or serial control - both of which are wired.

Yes the NZ regs are the law - they have been sighted in the courts - currently up to the 2014 standard is my understanding. If you have a commercial vessel, part of the survey is electrical, and you must have a certificate of survey to use a vessel commercially. Private vessels are still subject to the regs, but are not subject to the electrical survey. There is room there I would think so that if you don't follow or exceed the rules, you MAY have an issue if it comes to an insurance claim, especially if the electrics aboard caused the issue.

Absolutely Lithium (and other) battery tech is moving rapidly, and the regs struggle to keep up. I have done a few LifePo4 systems for customers, using Eve or Winston cells, but they ALL have Class T fuses, BMS serial controls to control solar, shorepower, Wind gens, external reg Alternators etc, and they all have audible and visual alarms to meet the NZ (and the US ) regs. Trying to keep up with the play....

Ooops ! brain wasn't engaged when  I wrote that ! but I think the fuses installed are T fuses as HMB electrical did the hook up.  The Anderson connector was installed so that I could (in theory ) quick- disconnect the "burning" battery before picking it up and throwing it outside (not going to happen)  Having said that LiFe Po chemistry supposedly doesn't catch fire anyway and if it did well its in an Aluminium case but then presumably that wouldn't help much at the temp of flaming lithium. It also had to be in its own compartment in case it of gasses ? but then this type of battery does not off- gas apparently and I used wood because the battery was in its own metal case. It did highlight as the inspector commented that the regs were lagging the technology, I'm not sure they differentiate between the varying Li batt types. 

 

 

 

 

[Frank 157]

16 hours ago, Adrianp said:

I built my system using Winston Cells and the REC BMS that talks to the Victron Cerbo GX, MMPT and Inverter. 

It's been in the boat 2.5 years now, done the usual Xmas cruises, a 6 month trip to the islands and the we often run a dehumidifier off the inverter while sitting on the mooring so the batteries haven't had an easy run. They have just dropped from 99% State of Health to 98%, so it seams they have a long life ahead of them! 

Doing the design and install myself has been the scariest boat project I've ever done as there is so much info to wade through and so many ways to do the same job. 

For us in a cat, the weight saving is awesome. We replaced 400kg of AGMs and Generator with 120kg of LiFEPo4, heavy duty cables, inverter, MMPTs, B2B chargers, etc. We now have double the battery capacity and can go for days without running an engine.  

 

+1 for that comment, a real PITA getting up to speed with the technicals and there did not seem to be "One best Way" but now its sorted its awesome.