I was planning to go with LiPo4 (lithium) battery set up, but I decided that the cost at this point just wasn't affordable. Worth it, but I have so many upgrade ideas, the opportunity cost wouldn't be worth it so I am shelving that for the moment. Maybe in a few years, I will revisit this option. In the meantime, I have decided to replace our two 8 year old MK Gels while they still have some life in them. I have a use for them to provide lighting in my 40' storage CONEX container (along with solar panels, charge controller, inverter). Anyway, I had previously replaced my two Red Top Optimas with an O'Rielly's 8D AGM battery and had initially decided to buy 3 of the Oreilly's AGM8D (their part number... good luck trying to find it on their website without that info and their parts counter people don't have a clue in my experience)
http://www.oreillyauto.com/site/c/detail/SSBL/AGM8D/N2493.oap?ck=Search_N2493_-1_-1&pt=N2493&ppt=C2389
So I decided that since I am going to weld up a new second battery slide anyway, I may as well make it fit 2 more 8D's and since I want them to all be the same age, now is the time. So I am ordering a 4th AGM8D. I know some have already put four of these monster batteries in their coaches. I know Dave M. added a fourth when he took out the propane tank, but I am wondering who has added the 4th battery to the same compartment where Foretravel originally put in two (on U270's) or three (U320's and U295's) in coaches of a similar vintage to ours. Did you put them on a slide? I plan to make bus bars to make equal length cables and still be able to slide them out fully without disconnecting the cables. I bought a pair of 500b. lock-in/lock-out 20" heavy duty full extension slides, and will support them on the vertical compartment walls on either side. Just wondering if anyone has pictures they could share of their 4 8D battery set ups?
Don
I have replaced the batteries and have no slide mechanism, it would be nice as it really is a back breaker lifting the 8D into position.
Looking forward to seeing your setup.
Love it, and it is very possible to add a 2nd 8D to the old LP tank location, the single 8D looks lonely. Have not found a need for the 5th battery, but the possibility is there. Plus for some types, a 4th could go in with the 3 original, but I am not the anxious. I do love having plenty juice available. The Xantrex 2500 unit seems perfectly happy with the new setting for the 4th 8D Gel, still charges at max of 102 amp, just a little longer if I pull them down. Since the 4th battery, have not ever had the generator start automatic from low voltage, have set for 12.215 VDC.
Educational stuff.
Thought about the fourth. On our 320 the upper single tray setup seems to have enough room for a double setup. I think the cabling and such could be moved to the other side of the compartment divider wall leaving space for a bigger slide.
Did not magnetically check for where the framing is in the wall although.....
I personally would not replace gels with AGM's myself. MK's web site shows 50% less discharge cycles life.
Don,
I don't remember the details, but JohnH posted some pictures that included some shots of his bus bar configuration. I don't think it was four batteries, but the concept of equal-length cables is very attractive.
What are you thinking about for bus bar dimensions?
One other enhancement I would like to see is a switch to remove the bank from the system.
Thanks (and good luck),
Trent
The batteries as far as I know can take up to 20% of their CCA capacity in bulk charge.
180 amps? Just less gen run time? What's the max charge setting? I thought 130?
Hi Don,
I will try to get out this afternoon and take a picture of the 8D batteries in my coach which is the same as Dave Ms (2001 36', U320). I have a feeling the batteries are not in the same location on every coach from year to year, length and model.
I have three 8Ds on the drivers side bay where the fuel tank is located. I found a picture. The batteries are behind the orange reel with the blue hose. Two lower batteries and one up above on a pivoting shelf. Batteries are oriented E-W. The 01's with a slide on this side (and maybe other years too) have extra structure along the driver's side. This makes getting these batteries in and out an epic feat of leverage. Probably easier than in the middle of this bay though where the Aqua Hot is on mine. On the other side is the big LP tank. I want to pull mine as Dave did and use a much smaller tank, maybe a 5 lb refillable. in its place I want to add two more 8Ds with their own inverter and charger to power only the refrigerator (absolute max load, warm start up and making ice, is only 800 watts). A slide out tray on both sides would be nice. Somehow I seemed to have lost a month this summer and we are out of here for another three months in a few weeks ... so maybe next year. So many projects, so little time. I want to just go play. Here we come Barney!
Roger
Without a slide, certainly is a backbreaker, and on our non-bus style compartment doors, also an auto scalping shear ::) especially on the upper tier. So a slide is essential on our rig. I will do a write up when I git-r-dun.
Don
I saw John's set up and recognized immediately the practicality of that solution.
I think .25" thick minimum by about 18" X 2 (neg and pos) to allow for the shortest equal length cables that will allow full extension with the slides. I may even go to .5" thick stock... I like overkill when it comes to current flow!
I like that idea, however the practical implementation of it would be difficult if you want to switch each group of two independently. It would require a three bus bar set up, one negative and two positive and would complicate the cabling and take up more space which might compromise the ability to slide the banks all the way out without the cabling hanging up. I already have a way to disconnect the entire bank with Magnum Mini panel and so will likely leave it at that.
Don
I put four on my 270 a 99. It was easier then the current coach to put them in the same location. Just rebuilt the whole battery setup and put a second row on and then had a cross piece to bolt on to hold them in. Easy to slide in and out but I have no picture of it as it was two coaches ago.
Don, I used 3/8 x 2" stock copper aand drilled them for 3/8" bolts to hold the lugs to bars. Made my own insulators out of Epoxy and bolted them to a ply frame fastened to right side wall. Like it and glad I did it. There is room for a 4th 8D but we never seem to need the extra power evn with the res' fridge running all the time along with other stuff on that circuit.
You are being nice to us as you do not need any help with this project and thinking it out. ^.^d >:D
JohnH
Don,
Maybe I am not using the right terminology.
Right now, I have three 8D's, with the positives (and negatives) interconnected. At one of those interconnections, a cable takes off towards the Isolator, or somewhere in the bowels of the beast. If I want to remove the house bank from the system, all I have to do is to physically disconnect that one cable, and the house battery bank is out of the RV system.
When I go to a bus bar system, I expect to have three same-length cables going from each of those positive terminals to the bus bar. From there, I envision a fourth cable going from that bus bar into the bowels of the beast. To isolate the house bank from the RV, all I have to do would be to remove that fourth cable from the bus bar. My desire was to use a heavy duty switch to remove that fourth cable, instead of physically unbolting it.
You are talking about a fourth battery, but I don't foresee a significant design change, except the addition of a fourth same-length cable from that fourth battery to the bus bar.
Or am I overlooking some other beneficial attribute?
Thanks,
Trent
Don,
Have you considered other batteries than 8Ds? They aren't a size used in solar installations as you'll nearly always see something in either 6,4,or 2 volt configurations. L16 seems to be a much more popular footprint and you could fit 4 of them in your existing tray as they are much taller than the 8d size.
Something like this?
HD-Series Heavy Duty On-Off Battery Switch - Blue Sea Systems (http://www.bluesea.com/products/3000/HD-Series_Heavy_Duty_On-Off_Battery_Switch)
. I drilled and tapped for 3/8 bolts and added of course one extra for the power feed to inverter, and the same set up for Nuetral/ground cables etc. To answer Trents Question "yes you just remove this one, or put a disconnect on it"
I am happy with the out come and will hopefully grab some extra life for batteries in the long term
JohnH
Chuck,
That should do it.
If you could mount it to the bus bar, you should only need one circuit out, unless you are sending it to other places.
One disconnect point would make it easy to run down other gremlins.
Trent
Trent,
I thought you were asking about switching each set of two 8D's independently, which I can actually see some use for. Of course switching at the inverter feed cable disconnects the entire house bank and is a good idea to eliminate any drama while disconnecting/reconnecting the battery cables cables. The HD 3000 series Blue Sea switches would be ideal for that and I will probably do that just to make safer while working in my Magnum mini panel where the 250amp circuit breaker/switch is. The Magnum literature states that you need 4-0 cabling form the battery bank to allow for the maximum possible current draw of the 3000 watt hybrid inverter. If using a class 'T' fuse, it needs to be rated at 400 amps, using the DC breaker as a DC disconnect, 250 amps is sufficient. I made my own 4-0 cables out of tinned marine cable, but the on battery interconnects, I used some of my original 3-0 cables. The inverter that shipped with our coach had permanently attached 2-0 cables (Heart Freedom 20). When I redo the battery connection scheme, I will probably just make all new short 4-0 cables to the busbars, but may go with the 3-0 because it is more than adequate for each batteries connection to the busbar.
Don
I looked at that size, and I don't think 4 of those would fit in the existing double 8D slide out, and certainly would be too tall for two levels. Assuming I could put 4 of these in that space;
http://pdf.wholesalesolar.com/battery-folder/USBatteryagm_L16_spec_09.pdf?_ga=1.196673132.1753084610.1420008002
I would only (only! :o ) have 780AH out of two banks of two (6VDC each) as they are 390AH each. With 4 of the 8D AGM's @ 245AH each, I will have 980AH total and just under 500 usable to keep the 50% discharge safe limit intact. That is far less than I would have gotten out of the LiPo4 1000AH cells (safely discharge up to 80% or so), but more than double what we had before.
Size comparison;
L16 battery dimensions
11.61" x 7.09" x 16.75"
8D battery dimensions
20.75" x 11" x 10"
Just my thoughts on the subject... besides I had already bought three a week ago and just ordered another now and so am committed!
Don