Converting to Lithium. Installing 4 new Battle Born units.

I’ve been seeing a number of battery threads recently so I’ll add mine. Our four UPG 110ah AGM house batteries died recently after just three years. The voltage was fine after charging. But it decreased rapidly after being unplugged from the charger. Like down to 10.5V when my battery monitor showed I’d used only 20 amp hours or so. So I’m guessing major sulfation. (I checked the connections and they were all tight.)

So this was my excuse to switch over to Lithium ion, which I had figured I would eventually do anyway. I’m in the middle of the project now. There are 4 new Battle Born LiFePO4 batteries in the space where the AGM’s used to be. We have a Kisae Abso 2000W inverter/Charger set for the “AGM” charging profile, which the Battle Born Factory (Dragonfly Energy) said would work fine with the Battle Born units. So on shore power, all is well. So far, so good.

However, I’ve had to disconnect the ACR between the engine battery and the house bank because the new lithium batteries don’t play well with the alternator. So I am installing two 30 amp DC-DC chargers to effectively isolate the alternator from the new lithium units. I’m also installing a small (Marinco 10 amp) dedicated shore power charger for the engine and thruster batteries, which will still be connected through their own ACR. (We are keeping our AGM engine and thruster batteries.)

I’m also replacing the MorningStar SunSaver Duo controller with a Victron MPPT 100/30 unit, as recommended by the people at Battle Born.

There are still a couple of details yet to be figured out. I think it will be a very worthwhile project... But practically speaking, the Battle Born batteries are not really “drop-in” replacements as they advertise.

John

What about a sterling power alternator disconnect?

Does this charger support not floating the batteries? Lithium batteries don’t like float charging.

The Sterling alternator disconnect would be to save the alternator diodes if/when the lithium battery management system suddenly shuts off the battery from the alternator, creating a huge voltage spike in the alternator. Since we will still be using a lead acid AGM battery as a permanently connected load for the alternator that should protect it from those kind of spikes.

It’s true that lithium batteries don’t need a float stage and would probably prefer not to have one, but the Battle Born specifications say a float voltage between 13.4 and 13.8 can be used. Our charger floats them at 13.4 nominal (I measure it at 13.34 usually). I verified this with the Battle Born factory people and they said that level float voltage would be fine.

The DC-DC chargers are to limit the current that the lithium batteries pull from the alternator. They will basically pull everything the alternator will put out, burning it up.

I appreciate the feedback, by the way. It is a fairly new technology and it would be great if someone points out something I haven’t thought of.

John

ah yes your alternator is to your engine battery first. no disconnect needed.

are the dc to dc chargers in parallel so you get 60 amps into the lithiums or split across different lithium batteries like 30 amps into 1 lithium and 20 into lithium battery 2?

The disadvantage of not going straight from alternator to lithium is limiting the charging current to 30 or 60 amps rather than potentially 100+amps. So charging will take longer.

are you setting the solar charger to a lithium setting and bypassing the engine battery and just charging the lithium house batteries? with the removal of the ACR are you able to charge the engine battery off the solar?

The two DC-DC 30 amp chargers will be in parallel. I know I am limiting myself to 60 amps when the lithium batteries could take a much larger charging current, but I am afraid of overheating the alternator, which is rated at 115 amps. Ideally, I should not plan for a steady alternator load of more than 80% of the rating and maybe less than that. That brings me down to 92 amps. If my engine and thruster batteries happen to be in bulk charging mode and my DC-DC chargers are gobbling up 60 amps (or more—they are rated at only 85% or better efficiency), that could easily put me over.

I am thinking to put a thermal relay on the alternator that will temporarily switch off one of the DC—DC chargers if it gets too hot but that is one of the details not yet figured out. I know Balmar has a thermal load managing device that fits their alternators but I don’t think the Volvo Penta engines like having the alternator switched out to a different brand. I found some thermal relays meant for cooling fans. I could cement the probe into a lug with thermally conductive epoxy. But I don’t see an obvious place to attach the lug to the alternator case. Still working on that one.

Regarding the solar controller, yes you are right, I am setting it for the lithium settings and bypassing the engine battery. Since there is no longer an ACR there, the engine and thruster batteries will not see any charging current from solar. But I think the house battery bank is where we would want that benefit the most. The engine and thruster batteries will never be used without the engine running and giving them a charge. And whenever we are connected to shore power, a small charger dedicated to just those two batteries will be topping them off and floating them.

John

Hi John,
Interesting project and one I have considered. If you have a chance, could you draw a wiring diagram and post it? I think I follow what you've done....
Thanks,
Rob

John that makes a ton of sense.

Ive long considered which design route to take. 1. alternator into engine batt and the DC charger to lithium or 2. the other way around with alternator and solar into lithium house and then DC charger into starter batt. definitely pros and cons to both approaches. - the outcome may change for you compared to me as I have 2 house batteries and I think you have 4?

One thing you may want to consider while doing this project is moving the propane solenoid off the engine battery to remove that parasitic draw.


you should definitely check out the wakespeed ws-500 alternator controller. Might save some headaches.
https://seabits.com/victron-wakespeed-battle-born-power-system/

Robvic":10p754e8 said:

Hi John,
Interesting project and one I have considered. If you have a chance, could you draw a wiring diagram and post it? I think I follow what you've done....
Thanks,
Rob

Click to expand...

Hi Rob, yes I will be happy to post a schematic. I have drawn and revised several already, and will definitely want to end up with an “as built” schematic that goes with the boat files.

Cutwater28GG":10p754e8 said:

John that makes a ton of sense.

Ive long considered which design route to take. 1. alternator into engine batt and the DC charger to lithium or 2. the other way around with alternator and solar into lithium house and then DC charger into starter batt. definitely pros and cons to both approaches. - the outcome may change for you compared to me as I have 2 house batteries and I think you have 4?

One thing you may want to consider while doing this project is moving the propane solenoid off the engine battery to remove that parasitic draw.

you should definitely check out the wakespeed ws-500 alternator controller. Might save some headaches.
https://seabits.com/victron-wakespeed-battle-born-power-system/

Click to expand...

Yes, we do have 4 house batteries. If you do the mod and have the room, you might want to consider three. You’d have 250% of your present usable amp hours, at less than 75% of the existing battery weight.

I moved the propane solenoid from the engine battery to the house bank a couple of years ago. Or rather the factory did that for me (along with replacing the engine battery with an Optima) when the boat was pretty new and we were having continuing starting problems and I was questioning rather loudly why the solenoid was connected to the engine battery. I have never regretted switching it over.

Regarding the Wakespeed WS500, I have considered that. It does appear to be specifically engineered for this type of project. I’m not sure if it would save headaches or just substitute new headaches for old though. I question whether it will work with the existing alternator and I think the existing Volvo voltage regulation would have to be disconnected which in turn would mess with the Volvo alarms, RPM output and maybe other things. I think there are ways around this but I am dubious about going to that trouble when a simpler way may work well enough for my application.

John

That’s fair. I’ve seen a few people who use these wakespeeds with after market alternators such as Balmar but I’m not clear on the implications with the Volvo evc

I’ll probably wait on the lithium upgrade on my boat as we are in the market to upgrade to a C30. The power would Sure be nice though.

The other factor I’m curious about with the lithium setup is cold weather performance. Lithium really doesn’t like to be charged when cold. The external locker offers very little insulation. It’s not clear if this is a real problem but my current monitoring does show that the temp on the batteries does get chilly.

Gavin, you are right that lithium batteries do not like to be charged when they are cold, or more specifically below freezing. In fact, they get downright nasty, growing needle-like metallic lithium spikes on the negative anodes, which can puncture the membrane, cause a short and put on a fireworks show. So the battery management system automatically shuts off charging below 0°C. You can still discharge them below freezing but this will slightly shorten their life. They are very happy just being stored below freezing though.

On our boat, the battery compartment is below the waterline and we always have some heat in the boat so I am guessing the battery temperature would not get that low. We have a temperature probe attached to one of the batteries. If it starts to look like it may be a problem, I can put an engine heater down there when we’re on shore power and/or maybe lay a thermal blanket over them.

The other thing they don’t like is excessive heat. They start getting a bit unhappy over 85°F but the issue becomes very significant over 115°F. If they spend significant time above 115°F it will definitely reduce their life expectancy. We don’t have ambient air temperature close to that in the northwest, of course, but I’m not sure how warm that lazarette gets with the engine running on a hot day. I’ll be monitoring it and will have to introduce some additional air circulation if it’s a problem.

John

Finished the installation, at least for now. I have a couple mods I could add if the thrusters seem underpowered because the alternator is already supplying 60 amps to the house bank plus recharging the engine and thruster batteries. So far that doesn’t seem to be a problem though. Also a mod for if the alternator temperature starts spiking too high. But that’s been ok too so far.

I am delighted with how the installation turned out. It gives us around 65% additional usable battery capacity in the house bank, faster charging, significantly longer battery life expectancy, and far fewer worries about a shore power outage or other unexpected event trashing the batteries. And replacing the four AGMs with the lighter Battle Born units eliminated the port side list that had been present ever since purchasing the boat.

Robvic":118ymjq7 said:

Hi John,
Interesting project and one I have considered. If you have a chance, could you draw a wiring diagram and post it? I think I follow what you've done....
Thanks,
Rob

Click to expand...

Here is a connection diagram of how the different components interface with each other. It basically shows the positive connections and leaves off the grounds. Also leaves off fuses, circuit breakers, bus bars and the shunt for the house bank metering system. It is the latest revision for what I drew in planning the system after talking with the Battle Born factory people over the phone.

I also drew some tangled full schematics before starting the job. I’ll try to clean one of those up and post that too. (I would like to have it anyway to put in the boat files.)

Here is the link. It should take you to the jpeg in my gallery. If you see the option to do so, tap on the higher definition version. You might have to go to the gallery itself to see that option. Not sure.



John

After looking at John’s layout I feel like I’m missing something with our new installation. We have an F300 outboard so our charging was limited. They installed 7 (maybe 8?) of the battle born’s with a dedicated 60 amp shore power charger. The 20 amp (reduced to 5amps in the settings) shore charger that came with the boat now only charges the two new lifeline agm starting batteries. They are for the outboard starter as well as the bow thruster. The outboard has two charging leads so one goes to the start batteries directly and the auxiliary lead to a 50 amp DC-DC charger and then to the lithium house bank. The DC-DC charger also has inputs for the 160 watt factory solar panel so it is only connected to the lithium bank. I was told since the factory solar was the type of panel that it was that a separate MPPT charger would only help a very small amount unless I replaced the panel. May look into that next spring. Not much sun right now. I can combine the lithium and agm’s if I ever needed to.

But engine stater temps were never brought up, I don’t think that my outboard has an alternator. Not sure how it’s regulated or if I could tie into it in any way. I’m definitely going to ask. I don’t care about shortening the lifespan or needing to replace the stator yearly or whatever. Just don’t want to lose the ability for the engine to charge the batteries since we don’t have a generator on our boat. Does anyone know if the Yamaha auxiliary charging lead disconnects on over current or high temps? I will ask the tech what he thinks.

I am hoping lithium’s would make me not regret skipping the gen set. The last couple boats we had with generators would end up having 3 x the hours on the generator compared to the engines. I do like the peace and tranquillity of the very quiet outboard and no generator humming away.

Did this installation of a known hazard affect your insurance?

Levitation":3rgbci2l said:

Did this installation of a known hazard affect your insurance?

Click to expand...

Yes, I had this and some other work done so my broker had our replacement coverage increased by an equal amount of the cost of the work.

Levitation":33atfe1j said:

Did this installation of a known hazard affect your insurance?

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Do you mean the batteries themselves being the known hazard? Actually, while technically a lithium ion technology, these batteries are Lithium Iron Phosphate (LiFePO4) which are very stable and not prone to the runaway heating effect that previous lithium ion technology has been known for. The energy density is slightly less, but there are also a number of advantages and safety is one of them. The internal BMS keeps them from being charged if the battery is below freezing, which could otherwise be a safety issue, and it also shuts down the discharge current if it gets to an unsafe level (unlike what would happen if there is a short in a lead acid battery bank). And it doesn’t generate explosive hydrogen gas like FLA batteries can. I understand the new Tesla Model 3 will be incorporating Lithium Iron Phosphate technology.

John

Wee Venture":39oqhikl said:

Levitation":39oqhikl said:

Did this installation of a known hazard affect your insurance?

Click to expand...

Do you mean the batteries themselves being the known hazard?

Click to expand...

For some reason I misread that comment and genuinely thought he was asking a legitimate question about my insurance since I added a couple of bucks in batteries. And now I’m mildly curious if the guy is a king mixer or was just attempting humor.

But anyway, another benefit is they run at a higher voltage so everything draws less amps. And battleborn does have LiFePO4 batteries with built in heaters for you people that boat in the cold. The Victron batteries have Bluetooth and cable interface remote monitoring options that connect with their battery control system. Remote BMS control will probably become the ABYC standard when they figure out LiFePO4 so battleborn may not be the right choice in the future if you listen to those brilliant gentlemen at ABYC.

I was told (not sure I believe it) that the Yamaha outboards make the rated amps regardless of draw. They dissipate the excess amperage thru water cooled fins surrounding the stator. So I shouldn’t worry about damaging the stator by pulling the full amps available to charge LiFePO4 batteries. I’m sure I will trade the boat before that question is really answered, but perhaps her new owner will come here and read this post and let us all know how it turns out. I did get the 7 year warranty on the F300. You’re welcome.

Are you able to use the parallel switch if your engine battery is too low to start the engine? I read that LiFePo should not be used to start an engine? If you set the switch to parallel without starting the engine would the LiFePo charge the AGM, allowing you to turn off the parallel switch and then start the engine?


Sent from my iPhone using Tapatalk

Alpina":1voa87x3 said:

Are you able to use the parallel switch if your engine battery is too low to start the engine? I read that LiFePo should not be used to start an engine? If you set the switch to parallel without starting the engine would the LiFePo charge the AGM, allowing you to turn off the parallel switch and then start the engine?

Click to expand...

Regarding charging the AGM starter battery, I wouldn’t think it would be the best idea to simply parallel it with the Lithium bank for a significant period of time to charge the AGM unless you introduce a DC to DC Charger in order to control the charge. However, the Battle Born factory reps say that—while it is true that you should not use the Lithium batteries on a regular basis to start your engine—it is perfectly fine to parallel the lithium bank with the AGM or flooded start battery on an occasional basis when needed to start the engine. This will not harm the batteries. But as soon as the engine starts, I would turn the parallel switch back off again. I have done this and it worked fine.

John

Thought I’d provide an update. I have been quite happy with the installation so far. Did some winter cruising and used it as an opportunity to check how the stock alternator on our Volvo Penta D4 300 would handle the load. It is a 115A alternator (Volvo branded but I believe made by Mitsubishi). I have two 30A DC to DC chargers between the alternator and the lithium battery bank to limit the load on the alternator and condition the charge. The contingency plan was to put a thermocouple on the alternator to switch off one of the DC-DC chargers as needed if the case temperature went too high. I had concerns about a built-in draw of 60A to the house bank PLUS a simultaneous bulk charge of the cranking battery and thruster battery (both AGM).

So far it seems to be ok without the thermal relay. I measured the alternator case temperature on different occasions with a high quality infrared thermometer at 1/2 hour, 1 hour, and 1-1/2 hours of cruising at 1750 RPM (about 7.5 knots for our R-31). The DC-DC chargers were both charging at maximum rate. I wanted worst case scenario where the alternator was turning fast enough to fill the demand but the cooling fan was not spinning full speed. (WOT for our D4 is 3500 RPM.)

The case temperature was fairly stable between 188 and 192 deg F. This seems to me to be reasonable, though I couldn’t find the specified temperature range for this particular alternator. (If anyone has this info, I’d be interested in knowing. Mitsubishi or Volvo model 3840181 12V/115A.) The ambient outside air temperature was 48°F, so I’ll try it again on a warmer day, but we have a full enclosure and the cockpit temperature was about 68 and saltwater temperature doesn’t vary that much from season to season.

I was also wondering if I might see a degradation of thruster performance, given that the alternator now has a greater pre-existing demand when thrusters are engaged. I didn’t detect any difference, however. They seemed to be as strong and long lasting as they were before, even when both thrusters were engaged at the same time. My contingency plan here was to install a relay that turned off the DC-DC chargers when the thruster control was turned on but I don’t think I’ll need it.

John

I have a 2018 Cutwater 24 with the 300 Yamaha and a Abso 20 amp charger. My 2 house batteries are dying and need to be changed. When I purchased the boat, the people I bought it from included solar panels and two LiFePO4 batteries from Battle Born...not installed. I've had opinions all over the place....glad to see all your input.
The problem is that I'm not battery tech savey. I'm nervous about installing the batteries and all the other pieces of equipment that are impacted...ie my thruster and engine batteries. I would appreciate any info that any of you have.