jrnymn7 wrote:
rjxj wrote:
Per Lands comments about resistance a while back: What size cable is your converter running through?
How many feet to the batteries? Mine was about 30 plus as it crossed to the other side and back.
Did you check voltage at the converter positve vs pos terminal of batt for voltage drop?
I also did what Land said, checked everything with temp gun and found that an anl stereo, gold, pretty boy fuse got much hotter than an industrial type anl. I dont remember the V drop.
I also upped my catastrophe fuse as it was getting hot. I was too far under sized.
Also had a warm spot at my system ground.
I'm still interested in your high water use. Was it all the top charging when maybe the sg was ok? I may be wandering off but just wondering and learning.
And Mr Mex, us beginners may be wandering some but you haven't seen any spitballs, mad magazines or playboy during class. :)
i have 48" (inches) pos and 24" neg of 4ga cable from pm to batts, 16" of 4ga between each batt for series/parallel, 30" neg and 12" pos of 2ga from batts to inverter, 30" of 6ga for pm to chasis gnd, 18" of 6ga for inverter to chasis gnd, and until i can make up my own heavier cable, 16" of 6ga from batt to shunt. i have a 100a fuse between batt pos and inverter.
i have not yet been able to check temps, but all my voltage readings are dead on, throughout; with the only discrepancy being between the pm's connecting screws and the battery terminals. but the cables from the charger to the batts are 4ga; 4' to the pos., 2' to the neg. so i can't see it being line loss? ... i think maybe it has to do with the screw type connectors on the pm. there was a 0.03 drop in boost mode 14.72 vs. 14.69, and a 0.01 drop in abs mode 13.68 vs. 13.67. the best i can do is get the multimeter probes on the screws themselves.
i checked voltages across the entire 12v (4-6v) bank, across each two 6v pair in series, each 6v individually, across the shunt at various points, across batts to inverter, and so on. everything was the same to the second decimal point.
after the batts sat for over 9 hours yesterday, with the 0.9a fridge on, my SG readings were in the 1280-1290 range, and the one rogue cell that was previously at about 12.65 was right up there as well... it appears that near 15v charge with the nautilis 15amper stirred things up a little.
i too am concerned about the water loss... maybe it's just the type of caps they used? i don't know.
i'm thinking i have way too much battery for my needs, but like i've said, i built the system based on the popular notion that bigger is better, and that a low slow discharge is best. i am going to seriously consider either eliminating one 6v pair, or splitting them into two 215a/h banks. lots to consider.
At 75 amps PM you may do better with 2 g but your runs are very short so that's good.
The piece of 6 g from battery to the shunt may be an issue.
If the inverter has 2 gauge, every thing in the battery side should be 2 gauge or heavier. Especially if it's running through that piece of 6 g. Maybe I dont understand the 6 g to shunt though. i asume the shunt works in series in the negative cable. I dont have a monitor so I havent used a shunt. Looked at Trimetric?
I went with 4-6's because of the peukert effect. I figured that my worse draw down would be when we have spent the evening watching tv etc and then had a lot of furnace time on a cold night. I set the furnace at 70.
So again, I designed my battery box with 4 batteries because I didn't know what all I would encounter when I actually use it. Along the way niner suggested battery separation and charging so I went with blue seas switches and now have the ability to charge them separately with the end goal going all the way back to some of the first stuff I read from these guys and that is short generator run time.
As it sits right now I can charge one bank with the Quick charge and the other with the PD4655 on boost. It takes a little babysitting but I wouldn't charge and leave the rig anyway.
Ok so I go full circle to last winter with the old TT and a 14.4 v converter and dead batteries. It was probably a fine converter if plugging into shore power but it couldn't do the job at 14.4.
Volts are pressure and it didn't have the pressure to push back in fast enough. I couldn't run the generator enough.
So my lesser issue right now and possibly yours too is the converter. My battery charger at 15.5 can give me short gen run times but my second source (converter) is still slacking at 14.4
So my next step, thank you Mr Mex, is the megga watt to get me two fast charging sources.
What we are up against with large battery banks and converters and NOT on shore power for days is just like the solar issue. The batteries have to be matched to the charging system. Even if you add solar, you may not be in any better shape, well I take that back in the respect that you wont be any better off unless your solar has an adjustable voltage so you can hit 15 ish. If your solar is doing 14.4 or 14.6 you would get more charge time during the day but over a number of days would your capacity stat to tapper off because you're not getting a good top charge.
I put all this stuff in my mind as I learn and think back of comments made on here. Mex say's in his equl post sure anybody can brag about a 10 year old battery if all it does is weekend use and stays on the cord. Someone else said we blow through tank after tank of $100.00 fuel but obsess over battery prices. I'm told my batteries will be shot in no time. Maybe I want my batteries to be shot in a comparatively short time because on the other side of the balance sheet my figures may tell me that I had minimal generator run time, less trips to the gas station, less wear on my vehicle, less noise.
Then I also look at these high charging voltages and say NO it doesn't result in less battery life because I have a set of four cheap gp 27's in my boat that have been hit with 15.5 for 6 years and work just fine and seldom need water.
Yesterday was messing with my boat stuff and pulled out a 2012 sams club gp 27 battery that I use for a trolling motor and had it in the TT last winter that kept getting the 14.4 volt charges. The sg gravity doesn't want to come up in it so I'll probably hit it with the Megga when it gets here. This is it's 3rd season of use and the one thing it hasn't had compared to my batteries that are strong.......high topping voltage.
That' just my ramblings, not saying it's all accurate. Just learning.
Thanks to all
I GOTTA GO, WIFE JUST HANDED ME A PACKAGE!!!!!! IT"S MEGGA WATT!!!!!
