Yet another lithium question

[Martin P]

Yes the Calira has breakers within it.
I was thinking I could remove the 240v in and the 240v out completely and route through a small consumer unit to completely bypass it.
The Calira control panel does not have the facility to show any info about the 240 system anyway and nor is there any other panel that does so that would not be a problem.

 

[Okta]

I get your point but having worked on quite a few chargers I don't think that kind of subtlety is something you'd get on the vast majority of MH chargers, all I've witnessed is the 'battery type' switch lowering the voltage threshold for bulk and absorption phases by around 0.5 volts.
If a charger was that sophisticated then I'd expect to see another setting for the Ah rating of the battery being charged because absorbtion time is proportional to capacity, again Ah selection is a rare facility on MH chargers.
Below is a chart showing the typical variation in profiles for Flooded, AGM and Gel, as you can see there's no variation in absorbtion time in the chart, only voltage differences. The AGM setting gives the highest charge voltage but the lowest float, probably best if you think you're likely to forget to switch off once the float stage is reached. Otherwise the gel setting would be best because the charge voltage is lowest.

GEL / AGM Battery – How to select power supply

Only charge GEL batteries using a confirmed and reliable, temperature sensing, voltage regulated charger. Never use a constant current charger! At 25°C/77°F keep charging current in the range of 2.…

inglele.wordpress.com

Both my current Schaudt EBL and my previous CBE DS have very different lengths of time for the absorption phase between gel and lead acid settings. The voltage changes between the two are marginal and both within acceptable Lithium parameters. The important difference of a gel profile is an extended absorption phase needed by this type of battery and not so good for other types.

 

[merl]

Both my current Schaudt EBL and my previous CBE DS have very different lengths of time for the absorption phase between gel and lead acid settings. The voltage changes between the two are marginal and both within acceptable Lithium parameters. The important difference of a gel profile is an extended absorption phase needed by this type of battery and not so good for other types.

Thanks that's interesting. Is that info in the bumf or did you measure it?

 

[Okta]

Thanks that's interesting. Is that info in the bumf or did you measure it?

For both systems the voltages were in the bumf but the duration of the absorption phases I read elsewhere. However the length of time the chargers put out the higher absorption voltage is fairly easy to observe. I usually pitch up and plug in mid afternoon when the battery should already be full from the work of the B2B. If on gel the higher voltages phase will still be going at bedtime but on lead acid it cuts back before dinner.

 

[merl]

The amount of time needed in the absorption phase varies massively with many factors but mainly depth of discharge and battery capacity, for that reason it's not normal to see time limits, typically chargers use a system where the current is monitored and while the current is falling the charger will stay in CV (absorption) mode, when the current has stopped falling and has remained stable for a period of time will the charger switch to float, alternatively the charger will also switch to float when the current drops below a pre-set current level too. As I mentioned previously, time limiting is not something I've ever seen or referenced with MH charger, I think there's too many variables available re battery choice to make it workable or reliable, It's something that you'd possibly see in a purpose made charger with a dedicated battery or a complex high quality bench charger. I've never seen reference to time limits in a motorhome charger let alone variable with battery type. I may be wrong but I think that what you're personally experiencing above is something to do with the actual battery type rather than the setting used?
Be interested to see where you read about it if you can find it.

 

[wildebus]

Yes the Calira has breakers within it.
I was thinking I could remove the 240v in and the 240v out completely and route through a small consumer unit to completely bypass it.
The Calira control panel does not have the facility to show any info about the 240 system anyway and nor is there any other panel that does so that would not be a problem.

Yup, you could add a separate consumer unit and bypass the Calira one entirely.
When it comes to the 240V AC side there is a lot more potential danger if it is done incorrectly, so great care must be taken. (this is a general comment aimed at anyone reading this thread).
Martin, from your posts and replies it certainly sounds like you know what is needed to be done and how to do it, so have fun

 

[Nabsim]

@merl the Schaut chargers showed time limits for each stage depending on battery chemistry however if it said 8 hours on absorption it didn't necessarily mean that's how long it stayed on it. If the battery didn't need it then it dropped out to float around 95% if my memory serves. The times given in the bumf wee maximum

 

[Nabsim]

I use two of the chargers that David mentions (IP22 30Amp Victrons) my hearing is a little the worse for wear on certain frequencies but I don't notice any noise from the chargers. Saying that they are usually only ever on during daylight when sound levels are usually higher. I could certainly sleep with one under my pillow though

 

[merl]

@merl the Schaut chargers showed time limits for each stage depending on battery chemistry however if it said 8 hours on absorption it didn't necessarily mean that's how long it stayed on it. If the battery didn't need it then it dropped out to float around 95% if my memory serves. The times given in the bumf wee maximum

Just found it Neil, 4 hours LA and 16 hours for gel! Must admit, I've never seen that before. If they only use time to govern the absorption period that's a pretty crappy charger? If I understood you correctly you think that 16 hours is a 'maximum' figure and the charger also has the more conventional current sensing as well and will only go to the 16 hours if the current sensing hasn't tripped it to float beforehand? In that case the timer is a sort of additional safety feature which is excellent.

 

[Martin P]

Yup, you could add a separate consumer unit and bypass the Calira one entirely.
When it comes to the 240V AC side there is a lot more potential danger if it is done incorrectly, so great care must be taken. (this is a general comment aimed at anyone reading this thread).
Martin, from your posts and replies it certainly sounds like you know what is needed to be done and how to do it, so have fun

Thank you for your help. You make a tremendous contribution to these pages
And thank you Merl, Nabsim and Okta for your insights.