BAC Forum
General Boards => Technical Support => Topic started by: Anand Shah on August 02, 2021, 11:07:59 PM
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Hi All,
First off thanks for the help in previous posts, we just got back from a 7k mile trip and were largely problem free.
I have a new problem that I'd love help on how to troubleshoot: despite a significant battery bank (the rig has 8x Lifeline 12V 180AH AGM batteries that are <4 years old), 500w of Solar (running on the original solar controller it seems), I barely get an hour of bank time before the battery voltage goes from 12.9 to 10.9 as seen on the Magnum controller, and that is just running the fridge (all other breakers turned off). Note that the Magnum panel shows a voltage that is 0.5v less than what the Aladdin shows me for the house batteries. All the batteries visibly inspect ok and I've tightened all the terminals which were fine anyhow. The fridge is a residential big fridge, the the inverter is a Magnum pure sine looks like 3kw.
This is all on a 2007 Marquis Lapis 45'
My instinct tells me to check each battery / load test and that I may likely fine a dead battery somewhere; However, the newbie in me doesn't know how to best do that. Do I need to disconnect the chain of batteries and pull each one out? What is the best procedure to do this? Do I need to disconnect at the inverter? Turn of the cutoff switch?
I may also want to upgrade the solar controller to an MPPT one, any instructions on things I need to do there? Inverter/charging setttings, etc?
Thanks in advance,
Anand
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Just wondering... What time of day are you seeing that final 12.9v reading for your house battery bank - before dark with full sun or at dusk/dark without the sun?
What is the wattage demand of your fridge?
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I see the 12.9 after a full charge plugged into 50A, but generally betweeen 12.5-12.8 with no load if solar is charging.
The fridge pulls 3-4A at 120V once running.
Anand
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Anand,
IMHO checking the batteries individually is a good next step. You need to isolate each one to check it. If you still need power while doing this, you should be able to leave shore power applied. Turn off the House Battery disconnect switch. This will isolate the batteries from the inverter & loads. Wait a few minutes for the Bird system to stop trying to supply 12v from the chassis batteries.
Then isolate and test each battery. First disconnect and insulate the + cable (s) that lead from the battery bank to the coach. If you are going to remove the batteries, BE SURE to take a picture or make a drawing of the hookup before disconnecting anything. When finished, be sure to verify you have 12V at the output terminals after hooking all the batteries back up. There is a diagram of the correct hookup in Coach Assist, pg 55 of the 07 Marquis/Patriot wiring diagrams.
Steve
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You might want to remove the ground from the batteries in the small compartment at the rear. On ours the battery cut off switch does not shut these off.
Also, we are dealing with batteries too except ours are Interstate flooded acid batteries and the company told us 3 years was their normal life. Lifelines say 48 to 60 months for AGM.
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Thanks to all for the replies, will follow your advice and thanks for the heads up on the ground. There is only one battery in the small compartment, and 3 in the next forward, and four more take up the bay on the drivers side forward from the wet bay, below the solar controller and transfer switch.
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Take a look under coach assist at the wiring diagram for the 07 Thunder. The layout for the batteries changes for the ‘all electric’ coach or the optional AGM batteries etc. Nowhere do I see the arrangement you describe with 4 on the driver side but only one in the small compartment.
I wonder if your battery problem might be in the set up if it is after market perhaps?
One alternate to your set up is 4D AGMs . 2 in the small compartment (for the fridge) and 2 in the top tray with 2 grip 31 AGM in the bottom tray for chassis batteries.
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Keith,
It is 100% aftermarket or some custom modification by a previous owner. The coach is all electric. I will take some pictures and post. 4 batts in the rear P/S (1 above the chassis batteries, 3 in the tray in the next compartment forward) and 4 in the D/D bay.
The slide out tray in the pass through bay ahead of the wet bay is in two parts - the P/S has a dometic freezer on a mini slide out, and the D/S has four batteries on a mini slide out. There is a false carpeted wall in-between. You make me think that maybe there is some issue in whether the banks are properly linked.
Anand
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As Steve has stated the place to start is the batteries, you will need to load test each battery and the best way to do that is with a battery load tester. I bought one at Harbor Freight that is 500 amp costs about $50 bucks or you may be able to borrow one from one of the auto parts stores.
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I agree with Lee, all it takes is 1 battery in the loop with an internal compromise and it shorts out the whole lot. Fred
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Sounds like the former owner has Mickey Rigged more batteries in this coach so who knows if they were installed correctly with the correct sized cables and connectors.
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Anand
The only true test of a battery is a load test to do this the batteries have to be isolated from each other and load tested individually of course each must be fully charged first.
In would not be surprised to find that you have bad batteries.
On another note when wiring a multiple battery it is important to try to match the cable size and length between each battery and that the positive and negitive pickup points be at opposite ends of the battery bank to maximize the charge and load characteristics of the battery bank and keep the batteries balanced
My guess is that with your bank setup this was not done correctly and as a result the batteries haven't been charging or discharging evenly resulting in premature battery degradeation and or demise.
Keep this in mind when replacing our batteries you may want to wire the bank differently to balance the load characteristics.
PS
although many battery companies may make claims of the longevity of there products depending on the cycle frequency and depth of discharge the average lead acid and even AGM battery life is 3 to 5 years . Now may of us can get almost double that but the riggers of charge / discharge cycles can greatly change that one way or the other the fastest way to destroy a battery is to kill it flat 2 or 3 times that will significantly shorten their lives.
Hope this helps
Eric
Hope this helps
Eric
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Eric and all -
This is helpful. These Lifeline 8DLs are unbelievably heavy :)
I checked all the wiring yesterday, it all looks good, of proper guage, and connected as you note below. I tested the charge voltage off the generator and that was also correct at 14.2V at each battery terminal. I disconnected several of them, and the first set of problems began to show up - two were at 10.9V. Charged them for a bit with the genset and they quickly recovered to 12.8ish volts.
I pulled one and brought it home (I do not have grid power on the land where I store my rig) and have charged it / attempted to "recondition"/ equalize it via lifeline's instructions and it is not looking promising. After an overnight 15A charge my load tester says it is at 0% SOH.
I'm guessing these batteries are likely bad :( - I was hoping it was just one. Another hole in the budget.
I'm tempted to go lithium b/c I think I can reduce to 4 300AH batteries and use half the space / regain storage and I'd get full DoD. But do have questions for those who have done it:
(1) Do I have to replace the BIRD relay with an MIB? Can the Alt charge the batteries in the same way it does now?
(2) Can I upgrade the remote from ME-RC to ME-ARC and gain custom charge functions on my inverter?
(3) If I replace the solar controller to put in an MPPT one is there a way to preserve charging of both banks and maintain connectivity to Aladdin?
I feel comfortable with the batteries and electrical - but am not so confident about the integrations in the RV.
Thanks for all the help so far.
Anand
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Anand
While at the Gillette FMCA rally I spoke with battery dealers. Nothing but lithium at the show.
Tim the owner at ‘Solar Energy Systems LLC’ was very helpful and informed.
With the OEM solar controller and the MS2800 inverter (Magnum) he said all I would need to go lithium would be a small controller unit for about $170.00 and of course the batteries.
If you will be attending the Beaver rally in Redmond Or. in September there will be an opportunity to attend a seminar on lithium.
I would like to see those pics of your battery set up. I can’t even get 2 x 8D batteries on one tray.
Hope this helps
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Keith +
See attached photos. Pretty certain these batts are dead. Will look up the folks you met in Gillette and see if I can get some insight on converting to Lithium, also following the other thread on this. Will report back when I figure out how to do it.
Anand
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Anand
You say you charged the battery for a "bit" and it quickly came up from 10.9 to 12.8. What do you mean by "quickly"? An 8D battery would require 10 to 12 HOURS to recharge from a badly depleted 10.9 volts and finally rest at 12.8 volts. Do not be confused by the quick surface charge that takes place when you put batteries on a charger. That surface charge will deplete as quickly as it appears. The voltage on that battery should be brought up over 14 volts during the "bulk" charge and then allowed to taper down for many hours during the "absorption" and "float" phase in order to be truly charged. I am wondering if you are not really getting those huge 8D batteries charged at all.
Richard
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Hi Richard
I’ve had them on shore power charging through bulk/absorb and float cycles for long periods of time (couple of days) during our trip a few weeks ago, this is what got me to wonder because they simply wouldn’t last very long when we stopped and had the engine off and were off shore power / generator., I removed them and put several through individual charging cycles for 12+ hours and none of the ones I tested hold charge for very long. The individual ones rapidly drop from 12.9V to 11.5 which very little to no load on them. I’ve load tested them and the load tester says it can’t get more than 200CCA (one of them only gave 16). I’ve tried the “reconditioning” function on my battery charger and it never finishes its cycle.
The charging circuits seem to work with the Gen Set on and Shore Power, providing 14.2 volts consistently across the batteries. I do not have power at my storage location at the moment.
Anything else I should be trying to see if there is potential to save these?
Anand
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Anand
It sounds like your assumptions are all correct and the batteries are sulfated beyond recovery. There comes a time when replacement is the only viable option. I faced that eventuality last Winter in South Texas during February when power was off for a week during freezing weather. I absolutely killed my bank of AGM batteries cycling between running the generator to charge them and then running my AquaHot furnace from the batteries (I was running low on diesel and could not replenish since all the stations had no power). Anyway, long story short; I could not find any AGM deep cycle batteries anywhere in the area. The only deep cycle batteries I could find were the flooded 6 volt golf cart batteries at Sam's. I detest having to check and water my battery bank since my battery bay is so difficult to access. Good batteries have been hard to find with limited supply and distribution during the pandemic. I hope you have better luck finding replacements than I did. I will use the flooded batteries I bought last Winter while my budget recharges and then I will replace them with AGM.
Good luck. Richard