As you all know, anything more than clipping the auto charger onto a battery is well above my pay grade, so I have some questions.For the regular charge before the conditioning charge, the Lifeline manual calls for a voltage limit of 14.3v at 77 F for absorb. I am assuming that is the point I have the controller switch out of bulk. Correct?Second thing is the Eco-W can handle doing that but can only handle one panel. That's not much of a C rate on a 8-D. Is it worth setting up that system to work on bringing one of the batteries up while the big system does another, or should I just work on them one at a time?I'll start searching through the post for what stand alone charge I will have to get to plug in at home. I am not interested in a fancy converter since the trailer never gets plugged in to anything but the solar.

JiminDenver wrote:. I am assuming that is the point I have the controller switch out of bulk. Correct?Yes, bulk -> absorb -> float

Thanks.After seeing some of the charging threads on here, 14.3v just seemed low. The conditioning/ equalization voltage is 15,6v and the recovery, that's just plain scary. lol Charge at a constant current of 5 % of rated (20 hour)capacity until the voltage reaches 15.6 volts (7.8 volts for a 6 volt battery), then continue charging at this rate for an additional 4 hours. Note that the charging voltage may get as high as 18.0 volts (9.0 volts for a 6 volt battery), so the power supply must be capable of outputting this level to maintain constant current. This constant current charge may take 16 to 20 hours.

My wet cells would boiling fluids big time at that VOLTAGE and CURRENT. I'm betting your AGM's will still be venting Hydrogen Gas during this process. Definitely would keep away from open flames, sparks, and red hot elements... My wet cells will start bubbling even at 13.6VDC in the NORMAl MODE. When it drops down to 13.2VDC STORAGE MODE then the bubbling stops. If i was running 14.3VDC verses 13.6VDC in the NORMAL FLOAT MODE it would be raining battery fluids haha...In my PD9260C charging uses the same 14.4VDC for the EQUALIZE MODE EVERY 21 HOURS FOR A PERIOD OF 15 MINUTES. This is the highest DC VOLTAGE I will see on this charger. 15.7VDC at high currents would scare me as well even for a short period of time...I am old enough to remember the days where the automotive shops would put 50VDC on a battery with 200AMPS of DC CURRENT available to be used. This was their quick two hour charge. They also had signs around that they would be not be responsible for replacing the battery if the top blows off... I saw go over the shop roof one time... People would be lined up waiting to be next haha...Roy Ken

jim i wouldn't charge an 8-D AGM within anything less than 50 amperes, let charging continue to 14.4 @ 25c until amperes slump to 3.0 then maintain the battery at 13.6 volts to a temp max of 28c.This would be when the battery is seeing daily cycling duty and the values above are for a single battery.I pondered the point of minimum acceptable charge rate and came up with a chemical deduction. Yesterday I called a friend Fred Polanski who handles the tech issues at an AGM OEM. He chuckled over the phone when he heard my assumption and replied ("your rationale is right o the mark")"The mat absorbed 1.300 SG electrolyte demands substantial amperage which encourages it to circulate"The result of chronic under-amperage encourages -excessive- acid starvation. Free electrolyte and soaked-mat electrolyte are two different animals.I noted this in my era way back when, with gelled electrolyte but that critter was a literal nightmare to manage correctly. if I was home I would have benefit of a lot more instrumentation. The only reason I have that divorced platform scale is to send it to Denver for recalibration. The gel battery could not be desensitized from reluctance of acid circulation thus it makes a horrible choice for regular cycling.One Megawatt 36-ampere power supply adjusted to 14.4 volts would make a suitable charging source for each 8-D but one of the two polarity bridges would have to be opened to isolate the circuit for the sake of the Megawatts.When I get home I will verify my idea that minimum charging amperage is only necessary until the battery reaches 14.4 volts and amperage slumps to 10% of total amp hour capacity of the DUT. For your 8-D's this would mean something in the neighborhood of 25 amperes.The data above is pure conjecture on my part. Ideas put to print. Proofing will involve instrumentation and forty to fifty cycles. This I have a gut feeling OEM is aware of and practices it but getting data out of them is like extracting blood from a turnip. The title of this is called THE IDEAL CHARGE PROFILE.Making this agree with a solar system will take some work. Compromises have to be researched and selected. But the batteries have a single demand that must not be ignored = chronic undercharging, regardless of which profile you settle on.I am pleased that I can offer this information on a level that most of you can understand (a sharp group) yet present it at a professional level.I was fooling myself that retirement meant abandoning research for a hammock. Can't train a Labrador to not whine when he smells water.

Wow45-50a is the best my system can maintain. I suppose I can add a switch to each battery to be able to separate them if needed.MexI can only speak for myself although I would imagine the feeling is shared. i really do appreciate having what I am ignorant about explained in terms I can almost understand. I hooked up the full system to the 8-D sitting at 12.88v. Between the time I hooked up the array and got back to the controller it was already in absorb at just above 7a. I have no way of forcing the amps, so I put the Eco-w on the battery sitting at 13.01v and set it's float at 14.3v since it wont hold a absorb voltage. It is pushing a bit over 2a.Once the absorb time is met, I will switch the Eco-W set up to the 8-D holding 13.1v and the MS and the first battery to equalize/ condition.I'll check into the Mega watt. You can explain about the bridges when it gets here. It sure was a lot easier with just a Eco-W and 230w panel on a Grp 27 FLA, then again so is a tent.

Charging the Lifelines questions | Good Sam Community

103 Replies

RoyB
Explorer II
Jul 11, 2015
My wet cells would boiling fluids big time at that VOLTAGE and CURRENT. I'm betting your AGM's will still be venting Hydrogen Gas during this process. Definitely would keep away from open flames, sparks, and red hot elements... My wet cells will start bubbling even at 13.6VDC in the NORMAl MODE. When it drops down to 13.2VDC STORAGE MODE then the bubbling stops. If i was running 14.3VDC verses 13.6VDC in the NORMAL FLOAT MODE it would be raining battery fluids haha...

In my PD9260C charging uses the same 14.4VDC for the EQUALIZE MODE EVERY 21
HOURS FOR A PERIOD OF 15 MINUTES. This is the highest DC VOLTAGE I will see on this charger. 15.7VDC at high currents would scare me as well even for a short period of time...

I am old enough to remember the days where the automotive shops would put 50VDC on a battery with 200AMPS of DC CURRENT available to be used. This was their quick two hour charge. They also had signs around that they would be not be responsible for replacing the battery if the top blows off... I saw go over the shop roof one time... People would be lined up waiting to be next haha...

Roy Ken
JiminDenver
Explorer II
Jul 11, 2015
Thanks.

After seeing some of the charging threads on here, 14.3v just seemed low. The conditioning/ equalization voltage is 15,6v and the recovery, that's just plain scary. lol

Charge at a constant current of 5 % of rated (20 hour)capacity until the voltage reaches 15.6 volts (7.8 volts for a 6 volt battery), then continue charging at this rate for an additional 4 hours. Note that the charging voltage may get as high as 18.0 volts (9.0 volts for a 6 volt battery)
, so the power supply must be capable of outputting this level to maintain constant current. This constant current charge may take 16 to 20 hours.
2oldman
Explorer II
Jul 11, 2015
JiminDenver wrote:
. I am assuming that is the point I have the controller switch out of bulk. Correct?
Yes, bulk -> absorb -> float

Forum Discussion

Charging the Lifelines questions

103 Replies

About Technical Issues

Related Content

Battery charging question.

LiFePo4 lithium battery charging questions

Solar and Lifeline

Battery charging question.

Battery Trojan vs. LIfeline