[electricboats] BMS Recommendations

I may need a new BMS for my 16S 48V LiFePo4 battery that I built in 2021.  Looking for recommendations.  I am running a 12kW motor and max current is on the order of 280 amps. 

I have the Thunderstruck BMS (Dilthium Design) and it seems to have failed.  I can't get it to see more than 10 cells and voltage readings are incorrect compared to my meter (Fluke) directly on the batteries or on the harness end plug using the breakout board supplied with the BMS for testing.  My connections on the harness all seem fine.  I have tried to reset the BMS from the computer using the USB interface.  No luck.  I suspect there is something wrong with the BMS itself. 

This Thunderstruck BMS does balancing and charge controlling but does not control input and output for the battery.  That's fine but it means I can only use a charger that the BMS can tell to shut down.  So there is some advantage to a BMS with input output control?  It can disconnect charging without needing to have communications with the charger.  That seems useful?  

So I am looking to see what others have done in this sort of installation. 

Thanks, Dan Pfeiffer
My Electric Drive Sailboat
http://dan.pfeiffer.net/10m/electric_drive.htm

Re: [electricboats] Battery Recommendations

This is interesting information. I also have a couple of epropulsion motors and had not seen this information about storage. 

Too bad that the epropulsion forum is hosted on a social media platform. 

I wonder if the sudden drop you see is from it going into sleep mode, so that you can't read the actual voltage? The Activator manual says it will not activate a battery in sleep mode. I don't have an activator so I can't verify what you are seeing. 

Reading the activator manual, there seems to be some odd things:

They say after 10 days it will self discharge to 60%, but then they say it will discharge to 75% after 20 days? 

I use very little of the total capacity. I have never been below 80%. So how do I get it to the preferred 60%? Run the motor for a several hours? If it automatically self discharges to 60% after 10 days then why would I need to pre- discharge it? 

One thing that irks me about the battery, especially if the discharge level is so important, is why the battery has no indicator of charge state? As it is I have to hook it up to the motor and controller to see the state. Or buy the Activator I guess. 

And how do I charge it to 60%? I'd have to babysit the charger and periodically unhook the charger and hook up my motor and controller (or activator) to see charge state?

If charge state is so important then why don't they have a smarter charger that can keep the battery at the proper level? I imagine most use cases include long periods of storage. 

All that being said, I do like the motor. I am amazed at how long the battery can run. 

-Steve

On May 29, 2025, at 11:45 PM, Walter Pearson via groups.io <pearson1854=comcast.net@groups.io> wrote:



Thanks for comments on ePropulsion and GrenerPower batteries. The Spirit Plus battery is only specified as Lithium Ion Polymer. The BMS may be working well in that it senses a problem cell, but could it also be that it failed to provide the cell balancing function which would produce that problem cell? There is no communication between users and ePropulsion; the dealers are our only option and finding a responsive one is elusive. I joined the ePropulsion group on Facebook and did see posts from others experiencing sudden shutdowns, but the group is moderated by ePropulsion sales and marketing, so technical help is scarce. The only dealer I have found that would address the shut-down issue claims there can be three possibilities - corrosion at connections, failed BMS, or cell failure. Corrosion is not likely, but narrowing down between BMS and cell(s) requires shipping and testing and confirmation videos, etc., - not something I want to do – nor pay to have done. An excerpt from the manual regarding storage and self-discharge:

 

Before long time storage, ensure the battery charge level is 60% around, store the battery in 15°C ~ 25°C (59°F ~ 77°F) ambient temperature. 

If the battery level is larger than 60% for more than ten days without activity, the battery itself will discharge with a small current around 100mA until it reaches the 60% battery level.

• Battery will actively discharge to 75% after 20 days without charging or discharging.

• If battery level is low for a long time, it will enter sleep mode. Charge to wake it up.

• During long time storage, activate the battery every 3 months by a charge condition and keep the battery charge level at 60% around. This activation is very important and it can help to keep the battery in good condition.

• After long time storage, fully charge the battery before use.

 

From my self-discharge data, there is evidence that the mentioned 100mA load is applied which increases the self-discharge rate for a short period. It does not quite reach the 60% level before continuing at a lower rate. It's the sudden drop I don't like. I plan to test with bollard pull soon to determine whether this occurs under load and, if so, whether shutdowns repeatedly occur at the same charge level.

 

<RexGDDPxcjM0G7HG.png>

 

I previously used the term sudden loss of charge (SLoC), but from subsequent charging, it appears that the battery does not suddenly lose 40% of its charge. It just becomes unavailable due to shutting down. See charge plot:

 

<4EqioggODdPJkvHm.png>

Note that I have the Spirit 1.0 Evo Remote which has a permanently fixed remote throttle and display panel. When the battery is removed from the boat, there is no integral charge level indication. I purchased the ePropulsion Battery Activator that displays charge level. I now have a grid charger and solar controller for nominal 48V LiFePO4, so might try the GrenerPower battery again and hope for one at normal shipping charge condition.

[electricboats] Battery Recommendations

Thanks for comments on ePropulsion and GrenerPower batteries. The Spirit Plus battery is only specified as Lithium Ion Polymer. The BMS may be working well in that it senses a problem cell, but could it also be that it failed to provide the cell balancing function which would produce that problem cell? There is no communication between users and ePropulsion; the dealers are our only option and finding a responsive one is elusive. I joined the ePropulsion group on Facebook and did see posts from others experiencing sudden shutdowns, but the group is moderated by ePropulsion sales and marketing, so technical help is scarce. The only dealer I have found that would address the shut-down issue claims there can be three possibilities - corrosion at connections, failed BMS, or cell failure. Corrosion is not likely, but narrowing down between BMS and cell(s) requires shipping and testing and confirmation videos, etc., - not something I want to do – nor pay to have done. An excerpt from the manual regarding storage and self-discharge:

 

Before long time storage, ensure the battery charge level is 60% around, store the battery in 15°C ~ 25°C (59°F ~ 77°F) ambient temperature. 

If the battery level is larger than 60% for more than ten days without activity, the battery itself will discharge with a small current around 100mA until it reaches the 60% battery level.

• Battery will actively discharge to 75% after 20 days without charging or discharging.

• If battery level is low for a long time, it will enter sleep mode. Charge to wake it up.

• During long time storage, activate the battery every 3 months by a charge condition and keep the battery charge level at 60% around. This activation is very important and it can help to keep the battery in good condition.

• After long time storage, fully charge the battery before use.

 

From my self-discharge data, there is evidence that the mentioned 100mA load is applied which increases the self-discharge rate for a short period. It does not quite reach the 60% level before continuing at a lower rate. It's the sudden drop I don't like. I plan to test with bollard pull soon to determine whether this occurs under load and, if so, whether shutdowns repeatedly occur at the same charge level.

 

 

I previously used the term sudden loss of charge (SLoC), but from subsequent charging, it appears that the battery does not suddenly lose 40% of its charge. It just becomes unavailable due to shutting down. See charge plot:

 

Note that I have the Spirit 1.0 Evo Remote which has a permanently fixed remote throttle and display panel. When the battery is removed from the boat, there is no integral charge level indication. I purchased the ePropulsion Battery Activator that displays charge level. I now have a grid charger and solar controller for nominal 48V LiFePO4, so might try the GrenerPower battery again and hope for one at normal shipping charge condition.

Re: [electricboats] Battery Recommendations

[Edited Message Follows]

Ok then, "self discharging" disconnect at around 40% means that your BMS is working fantastic, better than most. I am surprised that the epropulsion people didn't tell you as much.

Lithium batteries will completely not work again if you drain them down to zero volts. It is recommended to store lithium batteries long term at around 50%. So having a BMS that disconnects at around 40% could very well be a battery saver. To store them over the winter you need to charge them a little every month or get a programable charger that you can set to turn on at 45% and turn off at 55%. Since batteries "wear out" more on the top and bottom of the charge, this "middle charging" will have the least degrading effect on the batteries.

This is especially helpful with a battery that only has 500 cycles. This tells me that it is not a LFP (LiFePO4) battery but some kind of Lithium, maybe LMC (Lithium Manganese Cobalt), because the lowest cycle count I have ever seen on a LFP was 1000.

It being something like a LMC battery tells me that it is most likely a 12S battery when they call it a 48V and will need a 50.4V charger for a 12S lithium battery.

The GrenePower 51.2V, 32Ah LiFePO4 that I found on amazon is a LFP battery and will need a 58.4V charger for a 16S LFP battery. If you have a programable charger then you can charge either one of them to whatever you want.

Most LFP batteries that are called 48V are this 16S (16 cells in series) and output their power at mostly 51.2 Volts, but you have to be careful, I have seen some 15S LFP batteries. These 15S LFP batteries would put out most of their power at 48Volts which would be fine for your electronics but would need a special charger (limited at 54.7V) because if you used a standard 58.4V charger on one it would kill the batteries.

 

Being that weight is your primary concern, your best bet might be to stick with the Greenpower 32Ah, if you can get one that works.

 

The Greenpower looks like it uses the cylindrical cells in a 16S, 8P configuration. Couple reasons I personally don't like cylindrical cells is there is a lot of empty space between them, so they are less power dense for their size. Another is that for every P more than 1, the battery is that many more times likely to fail, for example an 8P battery is 7 times more likely to fail than a 1P battery.

But I don't know of any LFP batteries that small that don't use the cylindrical cells. I think all the LFP batteries that are less than 100Ah use them, so it might be your only option. 

You might be able to find an even lighter battery that uses LMC chemistry (or more Ah for same weight) but they will be more expensive, and they can catch fire.

 

So again, your best option may be the Greenpower (or similar).

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Re: [electricboats] Battery Recommendations

Ok then, "self discharging" disconnect at around 40% means that your BMS is working fantastic, better than most. I am surprised that the epropulsion people didn't tell you as much.

Lithium batteries will completely not work again if you drain them down to zero volts. It is recommended to store lithium batteries long term at around 50%. So having a BMS that disconnects at around 40% could very well be a battery saver. To store them over the winter you need to charge them a little every month or get a programable charger that you can set to turn on at 45% and turn off at 50%. Since batteries "wear out" more on the top and bottom of the charge, this "middle charging" will have the least degrading effect on the batteries.

This is especially helpful with a battery that only has 500 cycles. This tells me that it is not a LFP (LiFePO4) battery but some kind of Lithium, maybe LMC (Lithium Manganese Cobalt), because the lowest cycle count I have ever seen on a LFP was 1000.

It being something like a LMC battery tells me that it is most likely a 12S battery when they call it a 48V and will need a 50.4V charger for a 12S lithium battery.

The GrenePower 51.2V, 32Ah LiFePO4 that I found on amazon is a LFP battery and will need a 58.4V charger for a 16S LFP battery. If you have a programable charger then you can charge either one of them to whatever you want.

 

Being that weight is your primary concern, your best bet might be to stick with the Greenpower 32Ah.

 

The Greenpower looks like it uses the cylindrical cells in a 16S, 8P configuration. Couple reasons I don't like cylindrical cells is there is a lot of empty space between them, so they are less power dense for their size. Another is that for every P more than 1, the battery is that many more times likely to fail, for example an 8P battery is 7 times more likely to fail than a 1P battery. I don't know of any LFP batteries that small that don't use the cylindrical cells. I think all the LFP batteries that are less than 100Ah use them.

Re: [electricboats] Battery Recommendations

I just bought a DC house 12v 50ah battery for a trolling motor I use for trolling motor I use on my dinghy. Only got a couple hours use so far, but it seems good and it only weighs 20 lbs. Good luck. 

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Re: [electricboats] Battery Recommendations

I have only day sailed with the Spirit motor and battery, so my speeds
were always low and would rarely use up more than 10% charge. I was
gathering data on self discharge in order to figure out how to charge in
the off season and on day 28, the system would not turn on until I
connected the charger. It did accept a charge. I have repeated this
sudden drop in charge level while idle. The first time was with cables
connected and I subsequently found out Bluetooth is drawing power
looking for the wireless remote even when the system is off and even
though my remote is the wired model.

The sudden drop also occurs with the cables disconnected, but takes
months instead of days. Charging after these events is more rapid than
should be possible which indicates to me there is still capacity there,
but the BMS has seen a cell it doesn't like and shuts things down. A
dealer informs me that I would have to substantiate the problem, send
the battery for analysis, and then hope for a fix or a replacement. My
warranty would run out before all that could happen, so hence the search
for alternative power.



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Re: [electricboats] Battery Recommendations

I do transport my boat batteries here and there, so weight is an issue.
The GrenerPower at about 33 lbs.was about all I can handle. I have
thought about going down to the next size.



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Re: [electricboats] Battery Recommendations

When your epropulsion battery quits with 40% remaining, what exactly does it do?

 

Because if you are running near full throttle when it shuts off, then it comes back on and you are able to use it at lower throttle settings, then that would indicate voltage sag cutoff.

 

This could be because of the teny tiny wires epropulsion uses that cannot take much current without significant voltage drop.

 

Voltage sag may not be your problem at all, I'm just thinking out loud.

 

I saw one video of someone that hacked their electric outboard (don't remember the brand) and put in larger wires to the circuit board with larger connectors. If I remember correctly, he did this because his OEM connectors kept failing (something like every 6 months), NOT because of voltage sag.

I guess he was disconnecting and reconnecting several times a week on his dingy, while cruising and putting his dingy on deck when moving the big boat. And after a few months the pins in the OEM connectors would loosen up and he would have to wiggle it to even get it to work at all.

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Re: [electricboats] Battery Recommendations

I also have 4 of the 100 Ah LFP batteries (with Bluetooth) from WattCycle, I have had a problem with one. It disconnected itself (may have been my fault) and would not take a charge or show any voltage across the terminals. The Bluetooth app showed crazy cell voltages from 3.2V to negative 0.8V.

I researched and found some people had good luck disconnecting and re-connecting the internal BMS so that is what I wound up doing and it cured my problem and showed cell voltages nearly identical, and also nearly full. No issues since.

 

Why I say it may have been my fault is because I had left this one battery connected to a 2500 watt 12V inverter (12" long 8ga wire) in the front floorboard of my truck. I had been using this as a portable 110v power supply for a 7 ¼" circular saw. I had left it connected so I wouldn't have to use a resistor to reconnect it when I needed it again. But the next week when I went to use it, the inverter power switch was on but no lights or output from the inverter. I guess the switch got turned on while bouncing around and I thought my only issue was a discharged battery but it was the BMS issue above. It was easily fixable but I prefer things that don't break, as opposed to something that has a good warranty or is easily fixible when it does break.

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Re: [electricboats] Battery Recommendations

I have 4 of these currently running in my home UPS system, 2 are 2 months old, 2 are 5 months old, and no problems yet. These may be a larger (and heavier) than what you are looking for but they have built in Bluetooth and are still way cheaper that the epropulsion.

 

Re: [electricboats] Battery Recommendations

Thanks for your insight. I have not found any reviews specific to this battery. There are some posts regarding GrenePower batteries and don't see any red flags. Perhaps I might try again - after I determine my refund was credited. My ePropulsion battery is certainly high-priced and even so has reliability issues. It shuts down suddenly with over 40% charge remaining and finding the cure is not straightforward. Support from GrenePower was very good - after the initial smoke-blowing. ePropulsion support is negligible. Maybe I can get Will to do a tear-down? The search continues...

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Re: [electricboats] Battery Recommendations

My experience with having LFP batteries shipped to me is that they're shipped at around 50% SOC.  So I wouldn't expect to receive a fully-discharged battery.  And fully discharging an LFP battery can be hard on it.  So their comment about it being okay is off, in my view.

 

Prices like what you're seeing ($340 for 1.6kWh) usually indicate 'Made In China'.  Not a guarantee of low quality, but suggestive.  At least they're responsive to your issue; some similarly-priced brands are much less responsive.  There are so many Chinese-brand LFP batteries out there that it's difficult to keep up with the offerings.  And my impression is that a lot of them will miss the mark reliability-wise, as the primary goal seems to be to produce batteries at the lowest cost possible.  Many corners are cut as a result.

 

I recently picked up a pair of 12V x 100Ah LFP batteries from WattCycle for one of my UPSs.  I found that brand on one of Will Prowse's lists of recommended battery brands.  Price was good, and so-far-so-good on performance/reliability (six months in).  But I don't see a 48V model from them near the size you have (32Ah).

 

There are, of course, 'Made In USA' brands of LFP batteries (Battle Born for example).  Prices are usually much higher, and not as many make 48V models.

 

Are there better options?  Probably, but it depends on your priorities.  Usually we want the lowest-priced battery (for its capacity) that is still 'reliable' (won't leave me dead in the water).  But reliability is difficult to determine, and that's usually what you're trading off for a better price.  Battery teardowns can help expose the quality of a given battery brand/model (both design and execution), and that plays a large part in reliability.  I suggest looking for a teardown video of any candidate battery brand/model you have in mind that meets the rest of your requirements (price, capacity, size, weight, ...).

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[electricboats] Battery Recommendations

I appreciated the recent product recommendations for chargers and controllers. Just the right information at just the right time for me. Would anyone have similar guidance for batteries?

Based on limited internet specs and reviews, I purchased a GrenePower 51.2V, 32Ah LiFePO4 battery to power an ePropulsion Spirit 1.0 Evo Remote motor. It appeared to be well-designed, with good packaging and adequate documentation. However, there was no meaningful charge level – either voltage with multi-meter or from its own LED display. Response to my concern was that receiving a fully discharged battery should not alarm me. However, when it would not accept a charge – with flashing red/green on charger – I again expressed my concern, and they agreed to send a return label.

Is this an anomaly? Or do we have to accept the high probability of receiving batteries with bad cells or a faulty BMS? With 28% more capacity and 25% of the cost compared to an ePropulsion battery, this one still might be worth pursuing. Are there better options?

Thanks for any suggestions,

Walter Pearson

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Re: [electricboats] Solar system on a sailboat for 96v battery?

Big Thanks to Jerome, that is exactly the thing the OP needs.

 

And after being educated by Jerome, I was able to find almost the same thing on the big A webstore (just 72V instead of 96V).

I didn't need the 96V but I did need the 12A.

I only need 48V for the boat, and 72V for my Ebike, so I got some of these;

Re: [electricboats] Solar system on a sailboat for 96v battery?

Hello there,

I have my system battery bank in 96VDC too, and it is indeed more complex to find components than when you stay below 48VDC. That being said, you can source the components directly from China, with a lot more to choose from. In my situation, I have 8 strings of 5 panels in series, attached to 4 industrial MPPT controllers from IPandee. Each string is at around 200VDC. I have no shading problem on my boat, other than droppings from birds, so going with panels in series to up the voltage was an easy choice.

In your case, as you are on a sailboat and you will have some shading, you are correct that you should avoid putting your panels in series. I would avoid adding a DC-DC converter to boost the panel voltage before the MPPT though. A DC-DC has a ~95% efficiency, so it is a shame to lose power there. We never have enough power... ;-)

Based on what you described, I would go with a product such as this one https://www.aliexpress.com/item/1005005825627193.html, one per panel, and keep a few as spares. See Alibaba or Aliexpress for other products, I just Googled and found that one, but I am sure there are other brands doing boost and MPPT charging for 96VDC banks.

As an additional safety precaution, I would suggest you add a way to cut power from the panels to the MPPT charger when the BMS signals that the charge should stop. Cheap electronic components like the one I linked do not have compatibility to communicate on the BMS data bus to start and stop the charge, and only stop the charge when the battery bank reaches a set voltage. The key concern here is if there is a bug in the MPPT software that would not stop the charge, this could lead to a very serious security hazard, so the best way to avoid that is to cut the feed from the panel to the MPPT when the BMS says "stop the charge". 

I hope this helps.

Jerome

On Fri, May 9, 2025 at 11:10 PM Circe Strauss via groups.io <neriad6=gmail.com@groups.io> wrote:

I have the sailboat kit from Thunderstruck-EV, configured for 96v upon their advice for my power needs. Had I known the grief it would cause trying to find the electronics for 96v, I would never have gone with this. Unfortunately, I've already installed he ME1616 and had a custom gearbox machined for it. It would cost thousands to reconfigure the system for two 48v motors at this point.

 

I'm trying to set up the solar system rn, and wondering if anyone else has done this. I bought four Hyundai panels, bifacial, 48VOC. I thought I was going to just hook them up in series, but it's been pointed out to me that partial shading of the solar array would shut the whole thing down. So, as a starting point, I made a design:

 

Having a heck of a time finding a DC-DC converter with a ~100v output. Saw one on Amazon, (DROK DC Boost Converter 900W) with a prominent warning label about frequent returns. 

 

Maybe I'm going about this the wrong way. If anyone has done this, would greatly appreciate your advice.

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Re: [electricboats] Solar system on a sailboat for 96v battery?

[Edited Message Follows]

What about this? Split the battery pack in two and charge each half at 48V with it's own controller (would still need to string 2 panels together to get enough voltage).

Kinda like center tapping a transformer but center tapping the battery with the negative side of one charger and the positive side of another charger.

If you program both chargers the same, feed them with equal length wires from bus bars that are fed from all panels, and have a 16s balancer, I think it could work.

 

Those Genasun GVB-8-Li-56.8V-WP are almost exactly what I need for my boat, but they are only rated at 8A (while saying that people have been using them up to 9A without issue). My panels Max Power Current is 10.72A while the Short-Circuit Current is 11.26A.

My panels are only 370W with a VOC of 41.4V (Vmp of 34.5V) and I have been trying to figure out a way to mount 3 of these panels when I only have room for 2.

So at 405W I don't think the OP could use these (let alone the fact that the highest voltage I see for these is 62V).

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Re: [electricboats] Solar system on a sailboat for 96v battery?

Generally, you need higher voltage going into a charge controller than the battery voltage you are trying to charge (unless you have a boost controller like Paul above). The OP has 48VOC panels, so a max voltage of 2 in series of 96, but when charging will probably fall to around 84V.

A "96V" battery will have a working voltage calculated at 102.4V with a 116.8V needed to top of the charge, so 2 panels will not work for the OP.

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Re: [electricboats] 48V Backup Charger

Buy it. I have two similar ones that are only 17A (but realistically only charge about 15 to 15.5A according to my shunt). I use one of them for when I get no sun for three days and my pack gets below about 50%. It seems to work fine, it has a green light that is steady on when in bulk charging and blinks when tapering off charge on top. I try not to let it top them off completely because I cant program the shut off point, but I have forgot to keep an eye on it and it stopped when it was supposed to.

 

Before I got these 17A ones I used a 15A (actually charged about 13A) that was for 48V lead acid golf cart batteries. That one only would charge to about 56V if I remember correctly. But since it was half the price of a LFP charger (and I got it on sale for even cheaper) and most of the power in LFP batteries is around 52V, I figured I would try it out. It also worked fine although I never let it complete its charge cycle. I would set a timer on my phone and check my voltage every 30 minutes until I got to about 54V and turn it off. This 54V is would equate to about 95% of my amp hour capacity.

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[electricboats] 48V Backup Charger

Anybody have experience with these relatively low cost 48V chargers?  I was considering getting one as a backup unit. 

Like this.  There are many similar ones out there...

https://www.ebay.com/sch/i.html?_nkw=135185554533&_sacat=0&_from=R40&_trksid=p2332490.m570.l1313

I'd be interested in recommendations too.   A basic bare bones charger to have on hand as a backup for a 48V 16 cell 280AH LiFePo4 battery.   Pretty bare bones.


Thanks, Dan Pfeiffer

Re: [electricboats] Solar system on a sailboat for 96v battery?

What about this? Split the battery pack in two and charge each half at 48V with it's own controller.

Kinda like center tapping a transformer but center tapping the battery with the negative side of one charger and the positive side of another charger.

If you program both chargers the same, feed them with equal length wires from bus bars that are fed from all panels, and have a 16s balancer, I think it could work.

 

Those Genasun GVB-8-Li-56.8V-WP are almost exactly what I need for my boat, but they are only rated at 8A (while saying that people have been using them up to 9A without issue). My panels Max Power Current is 10.72A while the Short-Circuit Current is 11.26A.

My panels are only 370W with a VOC of 41.4V (Vmp of 34.5V) and I have been trying to figure out a way to mount 3 of these panels when I only have room for 2.

So at 405W I don't think the OP could use these (let alone the fact that the highest voltage I see for these is 62V).

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Re: [electricboats] Solar system on a sailboat for 96v battery?

Maybe a simpler solution is to arrange the 4 panels into two strings of two panels in series. Each string should have its own charge controller. That avoids the DC-DC converter, and gives some tolerance for partial shading.

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Re: [electricboats] Solar system on a sailboat for 96v battery?

Genasun make a MPPT boost controller for 48V LiFePo4 see Genasun GVB-8-Li-56.8V-WP, I've got 8 of them on my boat. One per panel.

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Paul J. Thompson
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(W)09 913 3110 (Mob)021 275 5001 (txt only please)

On Mon, May 12, 2025 at 3:16 PM gsxbearman via groups.io <gsxbearman=yahoo.com@groups.io> wrote:

You may want to go with a transformer.

Or just 1 boost converter and a diode for each Solar panel.

With the boost controllers I think you will loose the Mppt functionality of the charge controller, but I don't think that matters very much.

 

 

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Re: [electricboats] Solar system on a sailboat for 96v battery?

You may want to go with a transformer.

Or just 1 boost converter and a diode for each Solar panel.

With the boost controllers I think you will loose the Mppt functionality of the charge controller, but I don't think that matters very much.

 

 

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Re: [electricboats] Solar system on a sailboat for 96v battery?

One booster and one controller per panel is the way to go. That will minimize any shading issues.

On Sat, 10 May 2025, 09:10 Circe Strauss via groups.io, <neriad6=gmail.com@groups.io> wrote:

I have the sailboat kit from Thunderstruck-EV, configured for 96v upon their advice for my power needs. Had I known the grief it would cause trying to find the electronics for 96v, I would never have gone with this. Unfortunately, I've already installed he ME1616 and had a custom gearbox machined for it. It would cost thousands to reconfigure the system for two 48v motors at this point.

 

I'm trying to set up the solar system rn, and wondering if anyone else has done this. I bought four Hyundai panels, bifacial, 48VOC. I thought I was going to just hook them up in series, but it's been pointed out to me that partial shading of the solar array would shut the whole thing down. So, as a starting point, I made a design:

 

Having a heck of a time finding a DC-DC converter with a ~100v output. Saw one on Amazon, (DROK DC Boost Converter 900W) with a prominent warning label about frequent returns. 

 

Maybe I'm going about this the wrong way. If anyone has done this, would greatly appreciate your advice.

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[electricboats] Solar system on a sailboat for 96v battery?

I have the sailboat kit from Thunderstruck-EV, configured for 96v upon their advice for my power needs. Had I known the grief it would cause trying to find the electronics for 96v, I would never have gone with this. Unfortunately, I've already installed he ME1616 and had a custom gearbox machined for it. It would cost thousands to reconfigure the system for two 48v motors at this point.

 

I'm trying to set up the solar system rn, and wondering if anyone else has done this. I bought four Hyundai panels, bifacial, 48VOC. I thought I was going to just hook them up in series, but it's been pointed out to me that partial shading of the solar array would shut the whole thing down. So, as a starting point, I made a design:

 

Having a heck of a time finding a DC-DC converter with a ~100v output. Saw one on Amazon, (DROK DC Boost Converter 900W) with a prominent warning label about frequent returns. 

 

Maybe I'm going about this the wrong way. If anyone has done this, would greatly appreciate your advice.

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