Yes, thanks Paul for adding these nuances. One can only include so much of the details and my disdain for "drop-in replacement" lithiums stems more from my concern that many end-users will take this completely at face value and make no other modification to their boat's electrical system to accommodate the lithium. Moreover, board-level dual bus systems may be incorporated on some of the bigger names but that is most certainly not guaranteed on the cheap imitators sold at Alibaba and Amazon.
On Wed, Sep 15, 2021 at 5:55 PM Dreuge <dre...@gmail.com> wrote: > Riley, > > While I’m not an advocate for drop-in replacements, but your statements > about them cutting off ones VHF, depth, chartplotter, bilge pumps, radar, > etc. is plainly false. The BMS in these drop-ins use separate charging > and discharging power MOSFET, so yes the built in BMS can stop an over > charge but they are still able discharge as normal. This is in essence a > dual buss system, but at the board level. There are plenty of cruisers > using these drop-ins and many of them are sponsored companies you > mentioned, SV Delos being the most notable was sponsored by Battleborn. I > do know some people who prefer a relayed controlled BMS. For relays BMS > systems, you do want or should have separate charging and discharging > buses, but that is due to the nature of the two way flow of relays. > > The Lithium fires that we all hear about are not the same battery > chemistry. The Lithium batteries in laptops, phones, Teslas and some power > hand tools are the lithium-ions: LiCoO2, LiMgO2, … These have higher > energy density which is why the are used, but they are not as safe as > LiFePO4. While the Li-Ions are know to produce excessive heat, which leads > to thermal runaway (ie. fire/explosions), the LiFePO4 does not. > > > - > Paul E. > 1981 C&C Landfall 38 > S/V Johanna Rose > Fort Walton Beach, FL > > http://svjohannarose.blogspot.com/ > > > > > *From:* Riley Anderson via CnC-List <cnc-list@cnc-list.com> > *Sent:* Wednesday, September 15, 2021 11:39 AM > *To:* Stus-List <cnc-list@cnc-list.com> > *Cc:* Della Barba, Joe <joe.della.ba...@ssa.gov>; Riley Anderson < > svfreighttr...@gmail.com> > *Subject:* Stus-List Re: anyone gone lithium? > > Hi Joe and any others interested in this topic. > > I install lithium batteries as my side job and after installing lithium on > our 38-ii and other large boats and consulting on another half dozen boats, > I can speak with some authority on this topic. > > *The risk of serious electrical or fire damage can be entirely mitigated > by properly installing the right equipment and following a strict circuit > topology. Most people who have installed lithium do not do this and this is > precisely why we hear about "lithium fires" so commonly.* > > Before diving into the details, you should be aware that in order to > safely install lithium batteries on a boat, you need to buy top-quality > gear that is compatible with the exact lithium chemistry of your batteries. > Can you use an AGM charge profile from the old charger you have lying > around? Sure, you may be willing to take more risks than others but this is > not acceptable in a professional install and it also reduces the efficiency > of your expensive batteries that you bought for their high efficiency in > the first place! It is these "indirect" costs of making the lithium safe > aboard that will dramatically increase the investment cost. Also, in order > to take full advantage of the perks of lithium you need to be able to > efficiently charge the system. This means a substantial solar array or very > high output alternator (often requiring serpentine belts and larger > pulleys). *For the weekend sailor or anyone tied to a dock most of their > season, these costs cannot be justified over conventional lead-acid or AGM > technology.* > > My wife and I live aboard and spend our entire season on anchor or > mooring. This is where lithium shines. We have 720 watts of solar and 320 > Ah of lithium. *We run a fridge, separate freezer, fans, computers, > microwave, electric kettle, with enough excess power each day to either > make 6 gallons of hot water through the inverter or run a 5000 BTU air > conditioner on high for 5 hours through the night.* We have all the > luxuries of home and are never concerned about running out of power. > > *The details:* > > The Battleborn, Dakota, and Renogy batteries that advertise *a "drop-in" > replacement for lead-acid should never be used on a boat*. These were > designed for van-lifers who can pull over and escape if something goes > horribly wrong. > > The key with lithium is that you need to protect both your boat and > its electronics and your substantial investment in batteries. Lithium > batteries will not tolerate overcharging, this is where the fire risk comes > in. On the other hand, over-discharging will not cause a fire risk but will > destroy your battery. The "drop-in" replacement batteries "solve" this by > disconnecting their terminals in the case of either overcharge or > over-discharge. This is unacceptable on a boat for two reasons: 1) most > obviously, if you lose all DC power underway, you no longer have VHF, > depth, chartplotter, bilge pumps, radar, etc. 2) if the alternator is > spinning but there is no battery to accept the charge, it will send > unregulated voltage through the entire electrical system. > > The proper way to install lithium involves implementing a dual-DC bus > topology where all of the charge sources come into a single "charge bus" > and all of the loads run on a separate "load bus". Victron Energy is the > only company with off-the-shelf batteries and related components to > implement such a system. Of course, the savy DIYer can build their own > lithium banks and program a compatible battery management system to achieve > a similar end result but this involves a serious appreciation for the > nuances of lithium and circuitry design. Essentially, a battery management > system (BMS) will both balance the individual cells in a battery and > measure the voltage of each cell. If any single cell reaches its upper > voltage threshold value, the BMS triggers a relay to disconnect the charge > bus and prevent overcharging (keep in mind, there are other steps necessary > to protect alternators, I'll come back to this later). If any cell reaches > its lower voltage threshold, the BMS similarly triggers a relay > disconnecting the load bus to prevent over-discharge. The separation of > charge and load busses is critical as it allows the system to recover on > its own. In the event of a low-voltage disconnect, the charge bus remains > connected and the battery can recharge. In a high-voltage disconnect, the > loads are still connected and can bring the battery back down to a safer > voltage. > > To charge lithium from an alternator, you need a lead-acid or AGM in > between to act as a buffer (most commonly, this can be your starter > battery). The alternator charges the lead battery. Connected to the lead > battery is a DC-DC charger that is capable of three-stage charging with > LiFePO4 charge profiles. This charger then runs into the charge bus > mentioned above. The Victron Energy Orion Smart charger > <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Famzn.to%2F3kaCbG8&data=04%7C01%7C%7Cb20b077a74db44ffd84508d9785f10a9%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637673171966815395%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=lt5c3Y3Q8in7CClgvxpxVjVdBvQbD5HLkZ4F%2Fx%2BAnT8%3D&reserved=0> > is a great choice here (Bluetooth programmable and automatically detects > when the engine is running so that you cannot drain the start battery). > > The buffer battery protects both your boat's electronics from unregulated > voltage in the event of a high-voltage disconnect and keeps your alternator > from overheating. If you connect a 60 amp alternator to a 100 amp/hour > lithium, the low internal resistance of the lithium will allow it to pull > more amps than your alternator can keep up with. This will quickly burn out > the alternator. Not to say that direct alternator charging of lithium can't > be done, but it is usually cost prohibitive as the alternator needs to be > extremely high output and have a sophisticated regulator designed for > lithium. > > *The price:* > > Our lithium batteries, BMS, charge and load relays, shunt, wiring, bus > bars, and monitoring computers and displays all in came to about $5000. > This does not include the cost of solar charge controllers or panels, > inverters, or alternator charging via DC-DC chargers. A 200 Amp-hour system > could be done in the manner I outlined above with off-the-shelf parts and > slightly less sophistication for around $3000. I hope this gives you and > everyone else a good overview of what is involved in both the cost and > installation. > > After writing this all up I feel like I can justify a self-plug. As I > said, I do installs and consults part-time. If you're interested in > pursuing lithium and just want some guidance I'm happy to answer questions > with no strings attached. If you want a more in-depth consultation or are > in the southern New England area and want help with the install, my work is > high quality and my rates are very reasonable! > > Feel free to get in touch, > > Riley > (860) 538 8446 > > > > > > > > > On Tue, Sep 14, 2021 at 9:27 AM Della Barba, Joe via CnC-List < > cnc-list@cnc-list.com> wrote: > > My batteries are about shot and I am thinking of going to lithium > batteries. I have to say I thought I knew this stuff and it seems massively > confusing with a ton of directly contradictory information. One big issue > seems that if the BMS disconnects for any reason, that will do a lot of > damage to your alternator and perhaps other equipment too. Add to that my > regulator does not have a specific lithium setting, I would need to get > into the custom menus and try and make one. > What seems to be the best bet is just to connect the alternator to the > start battery and use a DC-DC charger to charge the lithium bank. Some of > them also take solar input, so that saves me buying a solar controller with > lithium settings, which is something else I don’t currently have. > > Joe > Coquina > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.paypal.me%2Fstumurray&data=04%7C01%7C%7Cb20b077a74db44ffd84508d9785f10a9%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637673171966815395%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=qMtLKcI2kzOfkjISgurXk02qvKl5c8UtPAbUFkGvNgI%3D&reserved=0> > Thanks - Stu > > > > -- > Fair winds and following seas, > > Charlotte Freeland & Riley Anderson > SV Freight Train > Middletown, CT USA > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > <https://www.paypal.me/stumurray>Thanks - Stu > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - > Stu > > > -- Fair winds and following seas, Charlotte Freeland & Riley Anderson SV Freight Train Middletown, CT USA
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
