Batteries, Chargers and Isolators

[ianr]

Hi all,

I have just discovered that my (SO419) engine and auxillary batteries are dead (50%) after only 30 months. The previous set lasted 43 months. It's a bit odd as I have solar (to the auxillary bank) and shore power. Both the Solar controller units and the stock Cristec charger were "off" powered down and I 'm not sure how long that may have been for.

I suspect that somehow the batteries have been over depleted without sufficient recharge.

Because both the engine and auxillary bank have expired I am wondering if the Cristec charger and/or the Cristec isolater might be at fault.

My question, that I hope someone can help with please, is; If I replace the charger do I also need to change the isolater? Is the "isolater" what other brands call a DC-DC charger. It would be good to get some boxes that can be monitored. I'm leaning towards Victron Smart devices.

Thanks,

Ian

[Don Reaves]

I'm sorry to hear your batteries aren't lasting as long as they should. Mine average 6 years or more, so even 43 months seems short.

If the isolator is like the one in my Sun Odyssey 35, it's really just a relay. It joins the house and engine batteries when the alternator is producing enough voltage to charge them. Normally, they shouldn't be connected together because you don't want them to try to charge each other.

The charger should have multiple outputs, one for each bank. This should keep the house and engine batteries charged without having them interact with each other.

[ianr]

Thanks for the feedback Don. Do you still have the factory charger?

I've read the Isolator manual and as you say it seems to be a very basic voltage distributor.

[sitara]

Hi Ian,

Your batteries should be lasting longer than that, you should not get two crook sets. I assume that when used you don't deplete below about 50% discharge, repeated deep discharges can shorten their life significantly. This suggests to me that there is some fault in the system.

The isolater is not a DC-DC charger, the unit on my boat used FET transistors to isolate the batteries when there is no input voltage from the alternator. When there is voltage from the alternator the two sets of batteries are combined. My boat was incorrectly wired in the factory so that the isolator always saw a voltage and so appeared not to work. There was a wire between the alternator and started that was not removed as specified.

I installed a Victron battery monitor to keep track of energy use, I also have solar panels that keep the batteries fully charged when the boat is not in use and I almost never use the Cristec charge with this setup.

Hope this helps

Rob

[Spritz]

HI, 
i had similar problem with standard charger, i just replaced with a VICTRON charger and a VICTRON Battery monitor, obviously after replacing the batteries with AGM batteries..... 

hope it might help 

[so40gtb]

I would suspect a wiring error or non-obvious load on the batteries as the culprit in their early demise. Any connection to the battery positive side upstream of the master disconnect must be traced out to be sure of its function. Owners with little electrical knowledge often wire things directly to batteries - not a good idea.

Voyageur begins season 11 with the same AGM battery set this spring. Four Group 31 AGMs for the house bank and one smaller AGM as a starting battery. The Xantrex inverter/charger installed in 2014 failed in 2022 and was replaced with a Victron unit. Solar controller is also Victron. The Cristec charger remains for emergency backup of shore power charging. The house bank is charged from the main 12V bus, while the starter is charged by the Balmar Duo-Charge DC>DC converter. So far, the Victron gear has been flawless. Next house batteries will be lithium-ion iron phosphate, but no apparent need to change at this time.

--Karl

[zaphod]

Feb 23, 2024 13:19:10 GMT ianr said:

Hi all,

I have just discovered that my (SO419) engine and auxillary batteries are dead (50%) after only 30 months. The previous set lasted 43 months. It's a bit odd as I have solar (to the auxillary bank) and shore power. Both the Solar controller units and the stock Cristec charger were "off" powered down and I 'm not sure how long that may have been for.

I suspect that somehow the batteries have been over depleted without sufficient recharge.

Because both the engine and auxillary bank have expired I am wondering if the Cristec charger and/or the Cristec isolater might be at fault.

My question, that I hope someone can help with please, is; If I replace the charger do I also need to change the isolater? Is the "isolater" what other brands call a DC-DC charger. It would be good to get some boxes that can be monitored. I'm leaning towards Victron Smart devices.

Thanks,

Ian

The batteries on Azura were also failing prematurely. In my case the previous owner had upgraded the house bank to 5 FLA group 31 batteries. I did find that there were wiring mistakes made when they expanded the bank, but more importantly, I figured out that the oem Cristec battery charger was not up to the task, and directly contributed to the battery failure. The problem is the logic in the charger. It will only charge in bulk/absorption modes for a fixed amount of time before it switches to Float. It will do this regardless of the acceptance current. This operation might be fine on the small 2 battery bank or upgraded 3 battery bank the boat shipped with, but it was entirely inadequate for a larger house bank. What was happening was that if the house bank was deeply discharged and then put on the charger, it would stop charging before the bank was at 100%, then it would just hold the bank at whatever partial state of charge it got to. Keeping lead acid batteries at a partial state of charge for long periods is very hard on the batteries. It causes sulphation on the plates which results in permanent loss of capacity.

Do yourself and your batteries a favor and rip out that Cristec charger and replace it with a true smart charger!

[Don Reaves]

Feb 23, 2024 20:21:11 GMT ianr said:

Thanks for the feedback Don. Do you still have the factory charger?

I've read the Isolator manual and as you say it seems to be a very basic voltage distributor.

Sorry for the delay (I've been in Antarctica for a couple of weeks).

My charger is the original Cristec from 2004. My battery bank has been upgraded slightly, but it still within the ability of the charger. I seem to be in the minority of owners posting about electrical systems in that my Cristec charger still works fine.

The advice already posted seems to be good advice, particularly if your battery bank has been significantly upgraded from the original.

[rene460]

Hi Ian, very disappointing when you have such an experience with your batteries.

I think the replies so far cover the mains chargers situation pretty well.  The only thing I would add is that it is worth making sure that any new charger you install has a suitable cycle for lithium batteries as well as the usual range of lead acid types, just in case you decide in the future to upgrade to lithium.

In addition, the solar system has not been in the discussion so far.  I am not sure why your solar system shut down as you described, unless it was the result of the battery failing, but I am wondering why the solar system did not keep up so the batteries did not go flat. 

It is worth looking at the solar charger while you are on the job in addition to carefully checking for any wiring errors.  Does your solar system have sufficient output to manage the larger battery bank? And a suitable capacity charge controller to match?  If you build up a schematic of your system as you trace it out, you will be able to identify any issues, or at least have more information to ask more questions if it is not clear what something does or why it is connected that way.  Also check the settings on the charger to ensure they are correct for your battery type.  This can be through dip switches, push button mode switch or data wire connections.  (I have seen each of these on different chargers.)

I know CTek has a dc-dc charger that manages solar and engine alternator inputs separate from the mains charger, and I assume Victron have something similar, again making sure that any new equipment also has capacity for lithium.  I have no barrow to push for either, or of course any other you may consider though those two seem to be mentioned on the forum more commonly than any other.  Of course you may have no intention of considering lithium, but it is preferable for it to be a deliberate decision, rather than finding your new charging system needs a further upgrade.  Just more to consider while working out how to proceed.

Please keep us all informed of what you decide to do, and how it goes.

rene460

[NZL50505]

I agree that it might be nothing to do with physical drain but more to do with incorrect charging profile.

I killed a brand new bank of Full Rivers in less than a year by having the wrong charging voltage profile being output by an old Cristec.

The error was less than 0.5v between the requirements stated in the battery product spec and the voltage being fed to them. That was enough to kill them.

I was forced to replace the dead batteriy bank and so at the same time I replaced the old Cristec charger with new Victron. All ok now.

So yes upgrade your charger(s) but also read the fine print of your actually batteries to identify exact target voltage for each stage of Bulk, Absorption and Float. You must be correct within 0.1v of spec to be confident your new batteries will perform. Modern batteries are far less tolerant of incorrect V profile than old batteries.

It is not good enough to simply set your charger to the generic profile eg “AGM” just because your batteries are AGMs. The charging output might be materially different to what your actual batteries require!

[MartyB]

To throw out a charger I went too..... I have a NOCO replacing the older Xantrex true charge I put on my boat 18 yers or so ago. What I like about it, is that I can charge two different battery styles! I can leave my starting battery a lead, and the AGM or if I choose to go lithium in the future, I can charge that one too. My old one only did lead, agm or gel. Both banks were charge at the same rate.
My AGM house has gone 4 yrs vs the deep cycle leads only going 24-30 months. I have been happy with the AGM. The dual purpose size 24 lead have done an ave of 8 yrs since I bought the boat per. With a 2GM Yanmar, I don't need a BIG battery to start it.
I've only had the NOCO installed for 6 months or so. I have noticed the house bank seems to be lasting longer before the low battery charge lights bells and whistles start going off. There is a built-in way for the charger to note if the batteries need a desulphated, it will do that automatically. It also lowers or increasing the voltage input to the batteries depending upon how warm or cold it is too.
It seems like one of the better charger options out there vs some.
I have a 2 bank 10A per version, there are upwards of 4 bank options.

Marty

[zaphod]

Mar 20, 2024 2:48:15 GMT MartyB said:

To throw out a charger I went too..... I have a NOCO replacing the older Xantrex true charge I put on my boat 18 yers or so ago. What I like about it, is that I can charge two different battery styles! I can leave my starting battery a lead, and the AGM or if I choose to go lithium in the future, I can charge that one too. My old one only did lead, agm or gel. Both banks were charge at the same rate.
My AGM house has gone 4 yrs vs the deep cycle leads only going 24-30 months. I have been happy with the AGM. The dual purpose size 24 lead have done an ave of 8 yrs since I bought the boat per. With a 2GM Yanmar, I don't need a BIG battery to start it.
I've only had the NOCO installed for 6 months or so. I have noticed the house bank seems to be lasting longer before the low battery charge lights bells and whistles start going off. There is a built-in way for the charger to note if the batteries need a desulphated, it will do that automatically. It also lowers or increasing the voltage input to the batteries depending upon how warm or cold it is too.
It seems like one of the better charger options out there vs some.
I have a 2 bank 10A per version, there are upwards of 4 bank options.

Marty

I am surprised your multi-bank charger can output different voltages simultaneously. Most of the ones I looked at did not have independent voltage settings for each output.

It should be noted that the charger size should be matched to the bank it is serving. Older boats such as your Attalia had simpler electrical systems and small house banks of only 1 or 2 batteries. A 10a charger might be sufficient to maintain a small bank, but bigger banks and/or deep cycle charging require much higher output to properly charge the batteries. The factory charger on my boat was a 40a charger, and I upgraded to a 100a charger. Even that 100a barely meets the minimum requirement for a restoration charge on my batteries.

[MartyB]

Zaphod,

Very possible that a person with 3-4+ batteries in the gr 31 or larger sized batteries, be them 12 or 6V setups, would need more overall amps to charge them as a single bank than a 10 amp per bank offers. At the same token, the charger I got over the 15 yr old model, has some things about it frankly that if one could find a larger charger with more amps per bank than 10, but has the same abilities, this could be a good option for the person reading this.
A 20 amp is more than ample for my use, especially considering that my boat did not come with a charger from the factory. The original owner charged both house and motor using the motor as a generator.

no.co/genpro10x2

That is a link to the one I have. They have some 5amp and 10-amp setups with upwards of 4 banks per unit. with a size 31 house bank, and a gr 24 starting battery, the 10 amp per bank has generally speaking, working fine. These units have some features that some may like for their boats.

Marty

[ianr]

Thank you for all the feedback.

I have had an electrician check the system over but no wiser as to the root of the problem as yet though I understand a lot more about the function of the charger and isolater.

I am going going to install a smart shunt and start monitoring (via Cerbo) more actively before deciding whether to replace the cristec.

When I do narrow down the issue I will share.

[tpd]

Hello,

I have a Cristec YP+ 12 volt 40 amp charger in our boat. It came installed from Jeanneau, and this is a new boat. Since the charger doesn't come equipped with bluetooth, I bought the bluetooth dongle and installed it this weekend so I can read the charger information on my iPhone. Our boat has a LiFePO4 house bank, and of course the charge profile was set to lead acid. I changed it to LiFePO4, and then noticed that the the charge profile chart was showing 28.8v during bulk and absorption, and 27.6v during float. Our battery banks are all 12v. I don't know why the app is showing 28.8v. 

Has anyone else noticed this?

Thanks
td

[ianf]

I presume, as everyone is talking about chargers, that you are using shore power. How are your sacrificial anodes doing? Could you be leaking current and do you have a shore power isolator?

[rene460]

Hi Tpd, I assume the 28 V setting is being seen on the Ap, not a voltage reading at the battery (which I don’t think would be physically possible no matter what settings are being used), but I would first check the battery terminal voltage with a voltmeter to make sure it is within the manufacturers specified settings.  If there is any doubt, turn off the charger until you sort out the issue or get a Marine eletrician to checkout the system.

After that it is a matter of checking the charger settings on the device itself and on the ap. to make sure they are all appropriate for your particular batteries.  I don’t know the ap, but would suspect it has some wrong data leading to it giving a wrong output.  Also check that the Bluetooth device is correctly connected.

Please let us know how you get on.

rene460