Once Again - LIthium Battery Install?

[Pat Anderson]

Here is what I THINK my lithium battery install might look like.



I know I need the lithium battery and a DC to DC charger., but not what else I might need. I want to use three charging sources: the Suzuki alternator through the Voltage Sensing Relay so it can charge both the FLA starting battery and the lithium battery, the solar controller (200 watts of solar on roof and an MPPT controller that has a lithium setting), and shore power.

The VSR, for those who don't have one, charges the starting battery first until it sense that it is fully charged, and automatically switches charging over to the house battery side. I know that would have to go through the DC to DC charger. The Suzuki DF200 has plenty of amps for that.

The solar can just go directly to the lithium battery with the controller set to lithium.

It is the last part (shore power) that is puzzling me. Do I need to replace the Guest 10-10? Can I just have it charge the FLA starting battery and run from that into to the DC to DC charger? Can I hook both the house side of the Voltage Sensing Relay and the starting battery to the DC to DC charger? Should I remove the cable from the starting battery so charging only happens when the engine is running or the sun is shining? Or something entirely different?

Help would be greatly appreciated from those who know whereof they speak!

[thataway]

[journey on]

Par, the VSR as you describe it is wrong, take it out. How about that for a simple statement?

So, now let me say this about that. The VSR will charge the start FLA battery from the Suzuk and when that battery reaches some level, change over to the house battery. Now, what happens when the house battery reaches full charge? The DC-DC charger and BMS ( I hope the battery has one) opens up and the Suzuk alternator current has nowhere to go and fries.

So, take the VSR out. And show the Li battery BMS even though it should be in the battery. This unit will both balance the Li cells and cut off the charge current.

Boris[/img]

[Pat Anderson]

[Pat Anderson]

[thataway]

The Suzuki engine "cable". goes directly to the FLA Positive and Negative terminals. (There will be the engine cable and one other cable to a bus bar or single terminal point near the FLA battery. The second cable to the FLA start battery will be directly to the Positive terminal of the FLA start battery.

No VSR.

The DC to DC charger goes directly to the start FLA Start battery bus bar terminals or stud, via a 40 amp breaker. This can also act as an "On/Off switch for the DC to DC charger". There may be times you don't want the start battery connected to the DC to DC charger. (Like when there is no charging of the FLA start battery, by engine, or the mains power battery charger.)

The Guest 10 amp charger goes directly to the FLA start battery bus bar terminals. (fused on both ends)

We have not "talked" about fusing or breakers. The DC to DC charger should have a 40 amp fuse or breaker at the output of the wire going to the Li battery. If the lead to that battery is more than a few feet, there should be another fuse/breaker at the end near the Li battery. (For example, in my 25, the Li batteries were under the bunk, so there was about 18 feet of wire between the DC to DC battery charger. In that case there as a 40 amp breaker at the output of the DC to DC battery charger and at the input of the Li battery.

I would put the mppt controller output to the input terminal of the Li battery. It would be fused (or breaker)

There will be a fuse / breaker from the li battery output to the house load. In my case, since I was running a 2000 Watt PSW inverter, I put a 300 amp fuse in place about 7" from the LiFePO4 battery. I put a 500 watt rated load battery switch between the Li Battery and the house load. (Be sure it is a good US brand like Blue Seas or BP.) If you are only running the normal "house load" then I would use a 60 amp breaker between the LI battery and the console or bus bar where you take the house load.

What battery do you run the windlass from? I used the start battery, thus used a 60 amp fuse to this circuit from the FLA Engine Start Battery bus bar. That needs to be near the busbar or terminal off the Start battery. You only want a couple of wires to positive terminal of the start battery. For neatness sake, put either a bus bar or at least a simple terminal for the cables to attach to the FLA engine start battery.

[Pat Anderson]

[Pat Anderson]

Renogy 12V 100Ah Lithium Iron Phosphate Battery w/ Bluetooth and 12V 40A DC to DC On-Board Battery Charger ordered and confirmed!

On to LFS for required buss bars, breakers, and fuses!

[Pat Anderson]

And I should add that the total cost of the battery and DC to DC charger directly from Renogy was $683, or about the same amount as two AGM batteries - I know this because I just put two AGM batteries in my truck camper before I got tuned in to lithium batteries. Honey found a $36 coupon that came off the top and the purchase was tax free with free shipping. Of course there will be extra cost for buss bars, breakers and fuses, and I may end up upgrading the on-board Guest 10-10 shore power charger, but this makes sense for me. This battery will last longer and provide more usable power!

And with Dr. Bob's explicit directions, I have no doubt that I can do this myself. The hardest part I think will be lifting out the two EOL FLA batteries!

[journey on]

Pat, I'll certainly draw you my delta on your map. Please send me your original. The changes are minimal, get rid of the VSR and show the BMS.

The battery you've chosen @ $515 is a good battery and has heat, BMS and bluetooth; though what you'd use the latter for, I don't know.

Dr. Bob has covered the fusing, but I assume that fusing is already in place, please check. As both you and I have the same year boat with only a couple of months difference, I'd look and see if there's a breaker right back of the throttle, on the bulkhead. That's where mine is. I also seem to remember you replaced your windlass, as did I, for the later model. I also assume you kept the original wiring from the battery.

One additional comment is the use of buses and junctions. I used these for the small battery connections: Blue Seas Terminal Mount. For junction points (where 2 or more wires meet) I used these: Blue Seas posts. I assume you already have
larger bus bars.

I also used Marine cables, Even the tinned marine cables are cheaper than DIY, though one has to estimate the length when you order.


Boris

[Marco Flamingo]

The diagram brings up a question I've had for awhile about adding a LiO battery dedicated to only my induction stovetop. If the VSR is eliminated, then the DC to DC charger goes only from the FLA battery to the LiO battery. I assume that the DC to DC charger is one-way, i.e., the LiO can't discharge back to the FLA.

Does a DC to DC charger have settings so that it can be configured specifically for this FLA/LiO setup? I ask because my understanding is that the LiO battery has a different preferred charge profile, generally faster and higher voltage. It seems like asking the lowly FLA, once at float, to then feed a starving LiO. Any issues with this? If not, why not?

[Pat Anderson]

[Pat Anderson]

[thataway]

To answer Mark's question: the DC to DC charger is "one way". I bought the Sterling (same as Pro mariner, Pro nautica. With this you can make any profile you want--but there is a specific LiFePO4 profile, as was as FLA and AGM.

The second question implied is that the Li battery may drain the FLA start battery. Because of this one can set limits on the DC to DC charger, and program so only works when the engine is running. This is one reason why I put a breaker or switch between the Li battery and FLA battery.

To give an example, I used the Li batteries to power our induction stove and the microwave, as well as refrigeration/freezer. I would charge the Li battery when we ran the outboard during the day thru DC to DC charger. Then I would switch off the DC charger, when I stopped the engine.

[ssobol]