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  Topic Review (Newest First)
02-15-2015 05:52 AM
Re: Cristec Battery Charger Default vs AGM Caution

I have 4 Exide Group 31's being charged by a single 60amps CPS3, and a single 80amp alternator. I don't think you have a problem. The specs on charging the gels were similar to a conventional battery. The AGM's do have the 'Capability' of being charged a rate of about 1/3 their capacity, but it's not required. In my case I could really use a bigger alternator, but I am about to install 540watts of solar. I may still install a serpentine kit and a 160amp alternator.

One issue I have with the Cristecs for my house bank is ventilation, it puts out a great deal of heat and is tucked under a rear birth. I may install a vent, and cabinet fan.
02-14-2015 11:45 PM
Re: Cristec Battery Charger Default vs AGM Caution


I have just read all of the other threads on this forum and am a little concerned that I have bought the wrong batteries!

The boat is a 2 year old Lagoon 400 Catarmaran and the cooked gel batteries were a big suprise as they were installed OEM. Previously we had a 480AH Gel array (Exide ES1150 x4) and I took the caps off after removing them to see a lot of gaps in the gel.

The only reason I bought AGMs is because I thought they were similar to Gels (what the battery wholesaler told me) but cheaper and more easily available in my location.

For charging we have 2x Hitachi 80 Amp alternators but more commonly we use two Cristec CPS3 OEM chargers at 40 amps each. We also have a solar array that puts out about 20A peak and is regulated by an OEM french Solar charge regulator which does not have any optional settings.

I have just purchased 3 Deka 8A4Ds and am a bit concerned that I do not have the charging capacity to charge them efficiently. Often when we are motor sailing we only have one engine on and it sounds like at 80A the alternators could get very hot. The Cristec chargers will also output a maximum of 80A but at least are better regulated.

I could have got gels in the same size (little less capacity) for a couple of hundred bucks more and could possibly still change them as I haven't yet installed them.

Any advice appreciated

02-14-2015 09:21 PM
Re: Cristec Battery Charger Default vs AGM Caution

Thanks Maine Sail,

Useful information. Yes I have Deka Intimidator AGMs but I do not have a remote temp sensor and am not sure if my exact model of charger can accommodate one or not as I do not have the manual and there is no obvious "Temp' input terminal. Without temperature compensation I presume that the 14.4V setting is deigned to be conservative and avoid overcharging?

Like I said in my previous post the charger appears to have three pots which I am sure can only be for fine tuning the voltages the problem is that I am not sure what each of them do as the charger also has a designated start battery output.

I have just removed a set of Gels that were two years old and had been cooked by overcharging (gaps in the gel matrix from drying out). I suspect the Solar array or the Engine Alternators are the cause but it is interesting that you comment that "this charger will not charge gels very well" what makes you say that?


02-14-2015 03:37 PM
Maine Sail
Re: Cristec Battery Charger Default vs AGM Caution

If you are using Deka AGM batteries, and your charger has a remote temp sensor, 14.6V will yield a healthier battery and help to limit sulfation.

Unfortunately "dip switch" chargers rarely if ever give good options for charging. Not all batteries will fit into a dip switch box..

There are many batteries that charger won't charge properly including GEL, TPPL AGM's and orbital batteries as well as golf cart and many deep cycle batteries....
02-14-2015 03:34 PM
Re: Cristec Battery Charger Default vs AGM Caution

BTW does the manual say anything about adjusting the potentiometers RV1, RV4 and RV5? Are these for fine tuning of the voltages?
02-14-2015 03:32 PM
Re: Cristec Battery Charger Default vs AGM Caution

Thanks Missing You,

I have just had exactly the same problem - swapped out Gel batteries for AGMs and got excited when I saw the manuals on Cristecs Website only to open up the chargers and find out that I had OEM versions not the retail so no helpful 16way selector wheel. With the copy of the manual page you gave I now know what to set my dip switches too!

06-06-2014 05:33 PM
Re: Cristec Battery Charger Default vs AGM Caution

According to the text in the manual, yes. But according to the would be just the opposite. Gotta love this stuff.
06-06-2014 03:43 PM
Re: Cristec Battery Charger Default vs AGM Caution

Yes Off-Off-On are what my switches are set to. That is the correct setting in the manual for Classic Sealed Batteries.

It should be to set Off-On-Off for AGM as per the manual just as follows:
06-06-2014 03:31 PM
Re: Cristec Battery Charger Default vs AGM Caution

Your switches seem to show they are currently

according to the labels on the switches.

But according to the illustration in the manual, "white" is ON and "black" is OFF, which contradicts the illustration of the switches--although they are labeled Off/Off/On there.

I wouldn't trust the manual, I'd email them for confirmation using words like "up" and "down" and make sure they are talking about the same funny switches, which don't look at all like standard DIP switches. And then use a meter to confirm it.

I'd bet whoever wrote the manual never actually saw the switch type that someone built your board with.
06-06-2014 10:27 AM
Cristec Battery Charger Default vs AGM Caution

I've been trying to educate myself on the batteries and the charging system in my OC45. I initially thought there may have been an issue with the house batteries and was giving the dealer grief, but I now think they are fine. However I did find one problem with the Chargers. My boat shipped with Cristec CPS3 OEM's,a 60A, and a 25A. I have the manual which is a good thing since they are OEM Chargers and the manuals offered on the Cristec website are for the retail versions, they are different. The retail versions seem to use a selector wheel, the OEM use DIP switches.

The charger's default factory settings are for Standard Lead Acid. My boat has AGM. Somehow the settings were not adjusted to reflect this. The difference as best I can tell is just in the Float voltage, 13.8 volts versus 13.6 volts for AGM. My Deka's clearly state 13.4~13.6 volts for float.

You might want to check your boat to see how it is set. One tip off might be to use a voltage meter and take a reading 'AT THE BATTERY' during Float/Maintenance charge. Don't rely on the panel read out, it isn't accurate. The chargers have a yellow plastic access cover that is held on by a single screw. You may need to use a mirror or a smartphone to see the settings on the starboard side.

How my boat was delivered.

Cristec CPS3OEM Manual.

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