400: Lagoon 400 House battery charging

[feebs]

I have a 2010 Lagoon 400 - hull #90 - purchased used about 2 months ago - so coming to grips with its systems.

Having trouble charging house batteries from either generator or engines. Solar is keeping 450 ah lithium batteries at full capacity during sunny conditions.

When I have either generator or engines running,the DC meter is showing a small discharge. I would have expected that this would show "charging" when the house batteries are below full.

Photos show my switch selection - is there something I haven't selected, which should be on?

Note when I select the "Shore / Off / Ship" to Ship with generator on, Shore power indicator light on main panel goes out. The Ship position provides 240 v when I have inverter on.

So have I made an incorrect switch selection - just wanted to cover this point before I call in an electrician

Thanks Brett




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[arsenelupiga]

I have L400 14 months now and no generator but have solar and engines & custom installed charging system.

However, when fixing solar panels, learned about smart controllers that drive charging. Only after figuring out the whole charging setup, found the cause with deduction - corroded connector. Fix was $8.

If you are charging and get negative current, check if you have any power user on. If not, I would start with controller. Controller may provide diagnostics that may help you solve the puzzle.

Sooner or later you will need to know how it works anyway.

[tuskie]

Brett,
It may be simply a matter of the DC meter not being connected to all input/ output wires on the house bank. AFAIK that's not a standard Lagoon meter. The only voltmeter on a standard boat is on the circuit board and it reads voltage at the board not the battery bank.

I note that you have lithium batteries fitted. I assume that you did not fit them yourself? When fitting lithium banks to a L400, quite a lot of modification should be undertaken.

This is a bit of a controversial subject, but most cruisers do not (should not?) simply replace lead acids, be they AGM, flooded or gel, with lithiums.
For more detail on this, refer to
www.marinehowto.com (see the Lithium section)

Depending on what has been done to you vessel's charging systems, no doubt you now have a "unique" boat. How your meters and electrical gauges read will therefore be different to all other L400s.

I would be very interested to know how your lithiums perform and how your boat has been modified to suit. Do you have external regulators fitted to your engine alternators? Have you replaced the original Cristec chargers? Does your bank have a Battery Management System? If so, which one?

I'm thinking of replacing my gels with lithium but don't wish to over complicate the system. Any advice is most welcome.

[feebs]

Hi Tuskie

Sorry for not getting back to you sooner.

Yes this mod was competed in 2012 by previous owner - installer was from Sydney ( I can provide contact details if required - please pm me if required).

Original Lagoon chargers are still installed. It has 4 x Braille 368 Lah & a BMU 150.

Not to sure about regulators on alternators - will have a look & get back to you.

They work well & the solar keeps them topped up, although solar is on roof, which I will soon change over to back of roof like Monte's setup - will have to get a drawing off someone for this.

Hope this helps Brett


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[tuskie]

Originally Posted by feebs

Original Lagoon chargers are still installed. It has 4 x Braille 368 Lah & a BMU 150.

Not to sure about regulators on alternators - will have a look & get back to you.

Thanks Brett,
The Braille lithium batteries seem to be a "drop in" type for the automotive/ racing market. Yours is the first yacht that I've seen with this brand.
They are quite expensive; I hope this equates to quality.

I don't know much about lithium battery systems; hence my query. Broadly, there seems to be two "schools of thought" regarding lithium. The first school just drops in Lithium as replacements for lead acid. If they work, then all is good. The other school ( as examples in the link in my previous thread) says that, while a drop in system will work, the lead acid charging regime will shorten the life of lithium batteries and perhaps make them more hazardous. Therefore, you really need to change your chargers, replace both alternators or fit external regulators, perhaps new solar controllers and incorporate a dedicated Battery Management System. Some recommend wiring upgrades, alarms, flashing lights and a whole bunch of gold plated electronics. The bottom line is to protect the precious batteries from anything over 14 volts during charging and under 11.8 volts during discharge.

I understand the latter bells and whistles will provide a great system, but I wonder weather I personally wish to go to this level of complication and expense. Likewise, I don't wish to spend a lot of money on lithium batteries as a replacement for my gels and find that the existing system of charging kills them prematurely. I'm looking for "middle ground"; a system that works, will last well and isn't overly complicated. I'm thinking it doesn't exist for lithium batteries.

If your system achieves this, simply, I'd love more details.

PS. We have 1100w of solar in a similar installation as Monte's. Mounted on 80 X 50mm aluminium box section cross beams supported from roof and from davits on SS poles/brackets. We ran wires back through the hole for rear steaming light. This was remounted on back of panels. Provides ample power as well as much desired shade.

[feebs]

Hi Tuskie,

As I am not aware of what additional resources have been put in place to protect my Braille batteries & after your last post, I decided to record house battery readings during different charging inputs. I have completed night readings at this stage & will get around to day time readings over the next few days.

House battery display is set at 450 amh as 100%.

Attached PDF

So I gather house battery charging has a voltage input limit set - would you concur?

[tuskie]

Originally Posted by feebs

So I gather house battery charging has a voltage input limit set - would you concur?

It would seem so. Then again, I'm no expert in LiFePO4 technology. Just a cruiser confused by the whizbangery.

Have you monitored house bank voltages when motoring? The alternators seem to be the biggest problems for lithiums.

With our L400s we have 3 battery charging inputs; alternators (Hitachi 80 amps ?), Solar via controller (s) and battery charger powered by shore power or genset.

My L400 is factory fitted with two Cristec CPS30EM 40 amp chargers. It has a setting (RCI setting #1) for 14.1 volts boost and 13.4 volts float. I think it will do OK for lithiums. Feel free to disagree!

Solar panels output huge voltages, but many controllers are programable to output 14 volts or less. Mine are; another tick.

Alternators produce charge voltages that (I'm told) can severely shorten the life of the precious lithium bank. As well, the lithium bank's appetite for amps can make alternators run so hot that they can melt. So the experts recommend that they be protected from each other by means of external adjustable regulators or whole new lithium friendly alternators. The Hitachis have a thermal overload cutout but I don't know if this is meant to operate continuously! Worth checking what you have.

The fact that your house bank voltage hasn't gone over 14 volts may be due to 2 reasons: (a) all your charge voltages are less than or equal to 14 volts (Great!), or (b) your battery management system is cutting off the supply of charging electricity when it goes over 14 volts. Not so great, unless your BMS is designed to manage charging rather than just be a back up "safety valve".

Lithium banks are such a large investment it's important to get the charging right. Cheers!

[monte]

I can't help with the the charging but I'll post some more detailed pics of the solar installation when it's daylight.

[casablanca]

Have you spoken to the supplier/installer? I know the boat and the battery supplier, and I would have thought they could sort out your issues.

I've got lithiums (different manufacturer) and a dedicated 240v charger (in place of the OEM Christec which didn't have a LiPo dip setting) supplied and installed by the same outfit.

One thing I have found is that the battery charger sensing is affected by any resistance in the system. I replaced the original Lagoon charger to battery cables with very heavy (welding) cable as the charger tended to sense full charge when the batteries were not full. Because the lithiums hold their voltage the electronics which is designed to determine the state of charge are very sensitive to any resistance. The original cabling is far too light.






Bob
CASABLANCA L420 #86

[casablanca]

Thinking a bit more about your problem.

The voltage shown on the main panel, 14.5 is high. These Lagoon installed meters are pretty useless, and mine always shows about 0.6V less than the ammeters ( I have 2 ) in my battery monitoring system. Fully charged my Lithiums are about 13.2 V Under charge they will get up to about 13.6. As we speak ( night, with some house load, TV etc., ) my battery voltage is 13.3 but the main panel is showing 12.6V. Batteries were full about 4 hrs ago at the end of a sunny day. Have a look and see how your voltages compare.

So your pics seem to tell the story that the battery voltage is HIGH so the Christec will sense this as fully charged and probably go to float or absorption. So the charger might only be putting out a few amps. Your BEP monitor should be measuring nett input/output to the batteries, so there will be some house load going out, and some float charge going in so the nett could easily be a small discharge if the charger is in float while you are running the charger. If you have the same Christec chargers 40A as my boat, they don't have an LED type panel. So I'm not sure how you can tell what the charge state is. There may be some indicator lights. If you don't have a manual for the charger you can download it from the Christec website.

When the solar is charging you would expect to see a change current on the BEP meter until the batteries are fully charged when your solar charger should be cutting back on the input. I take it that this is what you are observing during the day? That would tend to indicate that the BEP meter is set up OK. At night, with no input you should be seeing 2 or 3 A discharge with everything off, and maybe 15A discharge when your TV is on, fridge and freezer running perhaps.

I'd be worried about the 14.5V on your main panel. I suggest you see what voltage the BEP is giving you. If there's a discrepancy I'd ignore the main panel meter and rely more on the BEP.

I hasten to add I'm no expert, just a user like you. I'm a long way from fully understanding my setup, but as you delve in you get to know more bit by bit.

I'd say my system works pretty well on the whole but the biggest issue for me is the metering. I'm not getting the readings I expect and I'm pretty sure that this is because of resistance in the cabling/connections. I'm working on that.

The other thing is it's hard to find electricians who are fully conversant with these issues. Best to educate yourself as best you can before you start paying for "expert" advice.




Bob
CASABLANCA L420 #86

[feebs]

Thanks for your detailed response Bob.

Yes I am trying to gather as much information as possible - I don't have BMS or battery instructions ( but contacted supplier a few days ago for them, as they are not available on manufactures web site).

During solar charging - at full capacity, voltage was showing 14.8 v on both meters - MPPT was showing 14.7 v.

I read that Braille batteries can take charge at 14.4 to 14.8 v - this is what I need to confirm.




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[casablanca]

That's interesting. My setup is set for a max V of 14.1. Didn't know that the Braille was higher. Bit surprised about that.


Bob
CASABLANCA L420 #86

[tuskie]

Originally Posted by feebs

During solar charging - at full capacity, voltage was showing 14.8 v on both meters - MPPT was showing 14.7 v.

I read that Braille batteries can take charge at 14.4 to 14.8 v - this is what I need to confirm.

This is one of the problems with LiFePO4 batteries; the manufacturers sometimes lie or mislead with their specifications in order to sell more batteries.

Most of the experts suggest that for optimum battery life 14.0 volts is max voltage. Pretty close to what Bob is getting to his batteries on Casablanca. If you read carefully the battery manufacturers don't recommend charging to 14.8 volts and then continuing to pump that voltage for hours on end. Best charging regime is to get to max voltage (14 v ?) and then stop. No float, trickle or any of that lead acid rubbish. This can be a bit of a challenge if boat is already set up for lead acids.

In order to try to achieve the correct charging for lithiums I have bought one of the Battery Management Systems from this supplier. (No commercial connection)

MiniBMS

This system will cut power via a big relay ("contactor") to disconnect charge current when bank reaches 14.0 volts. It will also balance the cells and disconnect bank when voltage drops to 11.9 volts in protect from over discharge.
Cost, all up about A$400. Cheap insurance for an expensive battery bank. Other BMS are available, but some are overly complicated and some are overly expensive. Some are just as good as the one I bought.

Another alternative that I considered was to set my battery monitor to alarm when voltage reached (say) 14.1 volt and then manually turn off a big switch on the battery charge input. A bit "low tech", but hey, so am I.