PD9245 and Lifeline GPL-31XT testing

I was not sure how to read the date code stickers on the New Lifeline GPL-31xt.

One sticker says FO, and the other has a barcode and some numbers:
01541778 .

I fired off an Email to lifeline last night and this morning a response related that it was made in June 2015, but no other details.

After initial delivery, I bumped it upto and held it at 14.40v for a while Via my Meanwell but the amps had only tapered very slowly down to 1.21. I am use to a rapid descent of Amps when top charging my Northstar AGM, so this slow amp taper was unexpected and had me questioning the freshness of this battery.

The ends of the case were actually bulging a bit. They flattened back out a while after I removed it from the MeanWell at 1.21a at ~ 3.5 hours at 14.4v

Last Night, over 8.5 hours, I depleted this 125AH lifeline, and according to my 8awg leaded GT Power RC watt meter:

62.864 A/H
776.6 W/H

This would be an Average 7.4 amp load
This battery achieves achieves its 20 hour rating under a 6.25a load, So Peukert get in there and starts waving his thunder stick around at some rate at 7.4 amps

Minimum voltage recorded was 12.01v at loads upto 14 amps
Voltage rebounded to 12.23 the Instant I removed all loads from battery
6 hours later it had rebounded to 12.37v!

I found this impressive. I had a few doubts yesterday as to the freshness of this battery, and this quasi capacity test was to see the battery had been sitting around and got a quick partial charge before delivery. It read 13.00 volts upon receipt. I read the Lifeline response as to a June 2015 manufacture date, after I saw voltage rebounded to 12.37.

I Then removed screwy31 from PD9245. It had been held at 13.2v by the PD9245 for several hours at that point.
I attached the Lifeline, and plugged in the PD9245.

43 amps settled to 42.5. Input line 118.5vAC.
~ 15 minutes later I came back and saw 13.6, and 35.2 amps, and the pendant light blinking rapidly indicating storage mode.
I pressed the button for 14.4 and got 42.5 amps again and a raising voltmeter.

Now 15 minutes later 14.2v and 38.9amps.


I have a cheap voltmeter/Ammeter on the PD output.
V/A combo unit

While initially it read pretty close to my clamp on meter as to amp flow, when amps tapered way down, the combo unit reads 0.00 and the clamp on meter will read as high as 1.14a.

Voltage was really close.

I tried adjusting the calibration pots. They are extremely difficult to turn. I have a dozen different precision screwdrivers, but only one of them ( flat head) fit in what appears to be a phillips head and no dice on getting it to acknowledge currents under an amp.

I had to readjust the pot again this morning at ~40 amps to read close to my clamp on meter.

I am a bit disappointed with this, but Oh well. Perhaps a better 75Mv shunt and less temporary wiring on the meter leads

I Am not so happy that the PD decided to revert to 13.6v storage mode on its own when the battery obviously can take so much more.

But after a pendant toggling, it is now holding 14.5v and amps have tapered to 13.9 amps on the combo meter and 14.57 amps on my clamp on meter @ ~ 1:20 after starting PD.

Now to see when it goes into normal 13.6 mode

Between 13.4 to 13.6 my 31 consumes .048 more ampeage. Paying attention to ambient temps seems to occupy a more prominent place on my list. When I return to hot climes the battery goes into the refrigerator.

Your voltages are close enough. Those voltages should be no problem for your new Lifeline GPL-31XT battery.

I almost bought a couple of those batteries last week for our Class C motorhome and called Lifeline regarding their recommended float voltage voltage for the GPL-31XT battery. They said it was OK to float them up to 13.4 volts. That's an excellent battery, by the way.

(I wound up buying another brand battery because I needed a higher float voltage design.)

I started using my PD9260C in 2009 and have been using my home made BATTERY MONITOR Panel which has two 0-30DC VOLTMETERS and one 0-75 DC AMP meter on it out in plain view when I am camping off the power grid. The two 0-30VDC meters are tied each to a battery bank of two batteries. Of course most of the time I have both banks switched online so both meters read the same DC VOLTAGE most of the time. When running off the batteries I can watch both battery banks slowly start dropping from the 12.6-5 VDC level down to the 12.0VDC level.

I have never really worried about the exact DC VOLTAGE I read but for the most part I either see 13.6VDC or 13.2VDC when connected to shore power. When connected to shore power or generator when smart mode charging kicks in I see 14.4VDC for about an two hours and then it drops back to 13.6VDC after that. If I am not drawing any current it will drop to 13.2VDC. As soon as I turn on anything it immediately jumps back up to 13.6VDC.

My GP24 12VDc 85AH Interstates batteries have been doing just fine since I installed the PD9260C. I started with four of these batteries in 2008 and lost one right away from being over charged with my older single mode converter/charger. Boiled out the fluids and shorted the cores.

I have been running the remaining three Interstates ever since with no problems using the PD9260C.

When I start using my generator powering up the PD9260C after running down my battery bank to around 50% charge state and the 14.4VDC Mode starts up I see around 53AMPS on my DC CURRENT METER. This stays at 53AMPS for about 15-20 minutes and then starts slowing tapering back. after around two hours it is at around 7-8AMPS DC current. Then my PD960C drops back to 13.6VDC which shows around 6AMPS DC current on the CURRENT meter for an additional one hour charge to finish off at around 90% charge state then.

I do this routine every morning around 8AM when camping off the power grid. Once I get in around three hour of charging with the generator connected to the trailer then I am good to go again for the next day/night run off my batteries. If my batteries are not up to the 90% charge state then they will start dropping off alot quicker and I end up having to shut down the batteries before 8AM the next morning as this is usually the earliest time when I am allowed to run my generator here on the East side of the US. I have an alarm that starts beeping when the DC LINE drops to its 12.0VDC mark.

Roy Ken

Low battery in the meter can cause high readings.
Probably .1 high is correct and better than spec IMO.

I constantly see 13.3 on 2 meters whenever I go in the MH for 1 reason or another.
I thought I had seen a max of 14.6 at one time or another, but not sure
While charging, I consider 1 tenth of a volt in any stage not worth thinking about.
I still think the PD chargers do the different stages more by time, than actual battery voltage, but I could be wrong.
I really only know one thing for sure about PDs, that being whatever they do, it can't be done much better. (been using them 14 yrs)
They make batteries last a long time, and they some how do it with batteries consuming almost no water.

Mine usually was about .1 or so low; lots will disagree, but I feel this is "close enough".

I've since changed to a PD9260, it seems to be a bit closer; have some solar mixed in too, so no telling exactly how that's affecting the readings.

My 2 GC's are now 7 or 8 years old, and doing just fine.

Doug