Solar Amps Reading

[dunnah01]

Bored on lockdown so I thought I'd try to not blow up the van. I fitted two 180w solar panels and separate controllers directly to B2 batteries and they are performing really well in the French sunshine. The itch is that my Rapido has an ammeter function added to the CBE PC320-RA control panel which currently [pun] doesn't include the solar amp additions, although the volts display for B2 still helps out. It would be great if I could read the total amps being used/charged via the panel. Would it simply be a case of connecting the solar 12v solar controller supplies to the pin 2 on the Amperemeter:

 

[dunnah01]

Just to update, bit the bullet and tried it. Blew the van up!

Not really, works perfectly so now see +/- amps on control panel which is much more useful than just voltage of batteries

 

[dunnah01]

Still bored in lockdown started looking at my solar setup and batteries. My leisure batteries are grunt Lion flooded type. However, the sticker on the front of the battery says calcium calcium technology which I presume to mean the batteries are Lead/Calcium to make them low-maintenance. My solar controllers are set to the default float of 13.7 volts but Google says Lead/Calcium prefer 14.2 volts. So should I up the float a little bit?

 

[Lenny HB]

No, leave it as it is, 14.2v is the bulk charge & absorption charge voltage. If you float them at 14.2 you will cook them.

 

[dunnah01]

No, leave it as it is, 14,2v is the bulk charge & absorption charge voltage. If you float them at 14.2 you will cook them.

But Google recommends the bulk charge as 15.2 volts for lead calcium. The 14.2 volts is recommended for lead antimony.

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[Nasher]

No, leave it as it is, 14.2v is the bulk charge & absorption charge voltage. If you float them at 14.2 you will cook them.

Typical! Someone posts about solar and you turn it into a cooking thread ?

 

[Lenny HB]

But Google recommends the bulk charge as 15.2 volts for lead calcium. The 14.2 volts is recommended for lead antimony.

Only if you want to fry them.
It all depends on what google result you look at but the general opinion is an absolute max of 14.7v, with a recommendation of 2.4v per cell (14.4v).

Depending on what setting you have on your regulator but for me the ideal would be 14.4v for bulk & absorption charge with a float of 13.8v.
If your regulator is a multistage unit the absorbtion phase will ensure the batteries are fully charged.

 

[dunnah01]

I'll leave the controller at 13.7 volts and hopefully get less bored with lockdown and forget about it then ?

 

[autorouter]

But Google recommends the bulk charge as 15.2 volts for lead calcium. The 14.2 volts is recommended for lead antimony.

Why would you want to specify a voltage for the bulk charge? You only bulk charge if the battery has discharged by a significant percentage. Do you recharge at 15.2V when the battery is down to 30 or 40%? What charging current do you expect at that voltage? It's probably enough to overheat and reduce the battery life. The correct way is to limit the current to about C/5 (where C is the battery capacity in Ah), and let the voltage gradually rise to the absorption voltage. If your charger doesn't do that, ditch it and get one that does.

 

[dunnah01]

Why would you want to specify a voltage for the bulk charge? You only bulk charge if the battery has discharged by a significant percentage. Do you recharge at 15.2V when the battery is down to 30 or 40%? What charging current do you expect at that voltage? It's probably enough to overheat and reduce the battery life. The correct way is to limit the current to about C/5 (where C is the battery capacity in Ah), and let the voltage gradually rise to the absorption voltage. If your charger doesn't do that, ditch it and get one that does.

I thought (probably wrongly) that bulk charge, and in my setup the absorption charge was the voltage for most charging. I'm only dabbling with trying to get something for free from my solar panels on the basis that the quicker I can get a charge in the batteries when the sun is brightest the better.
The twin 20amp controllers were about a fiver but they've seen us through 6 weeks off grid lockdown so far so not really intending to change them.
The setup is two 180 watt panels on separate controllers feeding a pair of 105Ah lead/calcium leisure batteries.

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[autorouter]

OK, those two panels are never going to overheat the two 105Ah batteries. I suspect the 15.2V bulk charge would be, as they say, more of an aspiration than a promise