Charging Lithium Batteries

Thank you for providing the link.

Personally, I would be hesitant to install a single unit that could potentially disable a significant portion or even all of my charging capabilities in the event of a failure. However, the requirements of different boats vary.

Even when considering MPPT controllers, these devices have a relatively high failure rate, making the redundancy of multiple units highly valuable for cruising yachts, particularly those that venture into more remote areas.

Note:
The maximum alternator input power is limited to 400W (around 35A) for the smaller unit or 660W(around 55A) for the larger unit. It is not clear what happens if these limits are exceeded.
The 30A unit will only work with low-voltage solar panels.
 
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How do you find the VHF interference?

I'm wondering about the Renogy DC-DC/MPPT myself as it seems very good value.
We have had a Renogy Onboard combined dcdc/mppt unit for a couple of years now and can’t fault it. Connected to the Renogy One Core display & remote monitoring, 280w solar, 300a Renogy lithium. Guess you could say I’ve bought into the Renogy band wagon.
 
I confess I'm now having difficulty in finding the Epever DCDC and MPPT controllers. It was, strangely, not on the Epever website but sold by a number of their distributors. I could actually find no Epever DCDC controllers, at all, on their website.

But combined units are not that unusual

DC-DC Battery Chargers with MPPT Solar Input | Solar4RVs.

Though this one is a bit small.

I'm still checking the availability of an Epever DCDC MPPT controller, or even a DCDC controller - as I will have more time.

Given the function of an MPPT controller and if you have multiple and different solar locations, which would be the case on a yacht, you would tend to have multiple MPPT controllers. If this is correct you would be very unlucky if all your MPPT controllers failed simultaneously.

Jonathan
 
DC-DC Battery Chargers with MPPT Solar Input | Solar4RVs. Though this one is a bit small.

I'm still checking the availability of an Epever DCDC MPPT controller, or even a DCDC controller - as I will have more time.

Given the function of an MPPT controller and if you have multiple and different solar locations, which would be the case on a yacht, you would tend to have multiple MPPT controllers. If this is correct you would be very unlucky if all your MPPT controllers failed simultaneously.

Jonathan
The provided link shows a 30-40A unit priced at around $500 with an input voltage limited to 45V.

In contrast, the Victron 100/30 is available for approximately $100. The lower price of the Victron units together with superior performance and synchronised charging makes the option of multiple solar controllers viable.

The Victron 75/15 is only around $50.
 
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Slight thread drift, I've found myself in possession of a Silentwind and as far as I can tell I can't connect it directly to lithium using the supplied charge controller... What's the best way round this? I may just use it to top up the starter/windlass circuit and if it's producing enough power, the DC-DC should kick in and send some power to the lithium. This is assuming that I don't wire the DC-DC to come on with the ignition, but instead set it to start charging above a certain voltage.
(And I don't expect it to work very well since the Silentwind is unlikely to keep up with the 18A DC-DC)
@Sea Change: We also have a Silent Wind, Lithium batteries, Acid start batteries and are wondering how to connect the Silent Wind to the Lithium bank. Did you find a solid solution to connect the Silent Wind?

I found a post with reference to a solution whereby you connect a relais between the cable for the wind generator and the Silent Wind charger: “Have a relay that shorts the lines from the wind gen to the controller activated by the BMS ATC. This brakes the wind gen and stops power getting to the controller. It works on both windgens with internal rectifiers (5pin DC relay) and those without (11pin AC relay). Watt and sea use this system on their hydro generators to stop their pod 600 or to protect lithium banks and sell the appropriate relay for AC for 30euro. The principle works just the same for wind generators.”

I have a Victron Cerbo and am thinking of using this to operate the Silent Wind. Any thoughts are welcome.
 
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