Renogy 30A PWM Solar Charge Controller and AGM batteries

[CyrusL]

I've ordered my two LifeLine GPL-31XT batteries. I'm about to install them, but I've read that you have to set your solar controller so that it knows that it's charging AGM batteries so that it doesn't significantly reduce the lifetime of the battery. I can't seem to find any settings to that affect. I've seen some solar controllers are auto-sensing. Does anybody know if the Renogy PWM30CC-LCD is auto-sensing? If not, which settings should be changed? I'm attaching a .pdf of the manual which makes no mention of AGM batteries.

Thanks for all your help.

Cyrus

[Marc Kurth]

Originally Posted by CyrusL

I've ordered my two LifeLine GPL-31XT batteries. I'm about to install them, but I've read that you have to set your solar controller so that it knows that it's charging AGM batteries so that it doesn't significantly reduce the lifetime of the battery. I can't seem to find any settings to that affect. I've seen some solar controllers are auto-sensing. Does anybody know if the Renogy PWM30CC-LCD is auto-sensing? If not, which settings should be changed? I'm attaching a .pdf of the manual which makes no mention of AGM batteries.

Thanks for all your help.

Cyrus

Cyrus,

The charging parameters for Lifeline batteries are straight forward and printed on the side of every battery:

1)Charge at 14.2v to 14.4v until reaching 100% charge
2)When fully charged, drop down one volt to 13.2v to 13.4v.
These voltages are at 77F. Your charge controller needs to vary the voltages inverse with battery temperature.

It is very important to understand that your new batteries need to see the 14.4v continuously until they are full. This might be all day long if they are low on charge and your charging system isn't big. Simply "reaching" a given voltage during charging, is not an indication of battery charge level.

In reviewing the data sheet that you attached:
It would appear that the only charge voltage is 13.8v? This is not high enough to charge the batteries properly.

Auto-sensing for this purpose does not work. The controllers needs be programmed specifically for the battery - different brands of AGM's have different needs.

Have you involved your Lifeline dealer to help you stay on the right course?

Take a look at this condensed version about care and feeding of your batteries:
http://marckurth.com/batterycare2.pdf

Marc

[garbonz]

It does not appear the the Reno logo controller is very smart. You need an absorption mode after the controller reaches 14.4 volt that keeps the voltage at 14.4 and gradually reduces the current (amps) until the charge rate reaches a couple of amps or so. I would toss that controller and get a Morningstar one that is written in ENglish.

[garbonz]

Originally Posted by Marc Kurth

Cyrus,

The charging parameters for Lifeline batteries are straight forward and printed on the side of every battery:

1)Charge at 14.2v to 14.4v until reaching 100% charge
2)When fully charged, drop down one volt to 13.2v to 13.4v.
These voltages are at 77F. Your charge controller needs to vary the voltages inverse with battery temperature.

It is very important to understand that your new batteries need to see the 14.4v continuously until they are full. This might be all day long if they are low on charge and your charging system isn't big. Simply "reaching" a given voltage during charging, is not an indication of battery charge level.

In reviewing the data sheet that you attached:
It would appear that the only charge voltage is 13.8v? This is not high enough to charge the batteries properly.

Auto-sensing for this purpose does not work. The controllers needs be programmed specifically for the battery - different brands of AGM's have different needs.

Have you involved your Lifeline dealer to help you stay on the right course?

Take a look at this condensed version about care and feeding of your batteries:
http://marckurth.com/batterycare2.pdf

Marc

The charging voltage shut off is adjustable to 14.4, but still does not appear to be able to hold it there until the amperage drops to a couple amps and the battery is topped up all the way.

[vsheetz]

Appears a very basic controller. Not a intelligent multistage charger. I would suggest to obtain a better controller such as from Morningstar.

[CyrusL]

Hi everybody,

I appreciate your advice on this issue back in April. I figured I'd post an update with what I actually did.

Firstly, I moved the wiring for the existing battery from under the entry step to under one of the dining seats. That's where the last owner had his separate battery and inverter. So now I have both new LifeLine batteries together in one space with the inverter.

I replaced the solar controller with a Renogy MPPT controller that understands the battery charging characteristics. The one i got is this one. It may not be the best, but it's working great for me now.

Lastly, I replaced the inverter with a 3000-watt unit. It's the 3000-watt version of this one. I know it's overkill. I don't plan to use 3000 watts, but it does have the ability to wire outlets into the house system. I plan to switch over one or two of the house outlets to connect to the inverter instead.

The whole system is working great! We parked in the shade of redwood trees for 3 days of camping with friends and had plenty of power to make a pot of coffee each morning and use what lights we needed plus a fan (it was pretty warm). Once we got into the sun, it charged up again quickly.

I tried plugging the fridge (2-way, 120v & propane) to see if it was a good idea to run from 120v on the inverter instead of propane. Looks like that might be a fine option if I'm parked in the sun all day, but overnight it'll drain the batteries too much. Better to just run it on propane as that seems to work pretty efficiently that way.

Thanks again for all your advice!
Cyrus