New Battery Bank

[Turtle]

I redid the battery bank in the Sprinter. Here's the old bank:

Everstart Maxx Marine batteries from Walmart.

They're hybrid batteries designed for trolling motor-type amp draws, so if your amp requirements are minimal (light, Espar, computer) then they're fine. Not so much with my Microfridge, satellite TV w/DVR, computer, external hard drives, printer, Espar, and other stuff.

New batteries. Trojan J305E-AC 6-volt batteries, 305 amp hours each.

As a comparison to the popular Trojan T-105 (Golf Cart) batteries, the J305's (Aerial Work Platform) are about 2 inches longer, about the same width, but about 4 inches taller. And 20 pounds heavier. The next step up from the J series would be the L16 series (Floor Scrubber) batteries.

T-105
Amp hours - 225
RC @ 25 Amp - 447 minutes
Weight - 62 lbs

J-305E
Amp hours - 305
RC @ 25 Amp - 645 minutes
Weight - 83 lbs

The four 6-volt batteries are connected in serial pairs, and then in parallel, for one large 12-volt battery bank with 610 amp hours capacity.

The new batteries with Water Miser Battery Caps.

The Water Miser caps need not be removed when charging, filing or equalizing the batteries. They have flip tops for easy watering. When charging, the plastic pellets in the caps capture up to 90% of the moisture and acid droplets, returning them safely to the electrolyte in the battery cell. This reduces acid fumes, hydrogen outgassing, corrosion, and keeping the battery tops much cleaner and dryer.

These are considerably taller than the Everstart batteries, which necessitated some rearranging of fuse blocks, main busbar, and some cables. The white stuff on the battery tops around the terminals is just some white lithium grease used on the terminals to prevent any corrosion. Corrosion isn't likely under the bunk like you have it under the hood or on a boat, especially with the Water Miser caps, but it's better to use lithium grease, or dielectric grease, petroleum jelly, or something, rather than nothing.

The large cable just above the inverter is the main cable coming from the alternator connection at the cranking battery. It leads to a Class-T fuse block, to guard against the cable rubbing the vehicle body somewhere along the cable routing and causing a short. Connected on the other end of the Class-T fuse is the Pro Charging Systems Dual Pro "On The Run" inline charger. It provides three-step, regulated charging from the alternator, rather than just raw amps being fed into the battery. There are times when I'd idle to recharge batteries, and then just about the time the batteries were fully charged I'd get a long run that would end up overcharging the batteries. The Dual Pro charger will shut off when the batteries are charged to prevent overcharging. The Dual Pro charger then connects to the main positive busbar on the upper left there.

Notice how close the main positive busbar is in proximity to the negative battery terminal. It makes life exciting.

 

[Turtle]

Closeup of the Dual Pro charger, Class-T fuse block and inverter.

 

[tractorman70]

Very nice turtle, your sprinter, is it a 2500? If so, with all the gear you have onboard, what effect does have on your load capacity?

Very cool set up I'm taking notes!

Posted with my Droid EO Forum App

 

[danthewolf00]

83 pounds each wow now thats heavy power!

 

[layoutshooter]

I bet that Turtle could make more money setting up battery systems for trucks than he makes expediting. Good job. Good batteries.

 

[bluejaybee]

What I see when looking at his pictures is not how smart he is about all this battery wizardary, but how neat it all looks. And I know he probably hand crimped those cable connections hisself. To me, I see a work of art here. As someone stated above, turtle could make a living doing this.

 

[greg334]

Hey Shelled one, what's the deal with the jumper between batteries being smaller than the cable to the bus bar?

Also, did you fused batteries negitive side at the battery just in case or don't you see the need for that?

 

[layoutshooter]

I noticed that your inverter is a Cobra. Don't you think that you need a "sine wave" inverter? Please post your reasons why or not. Thanks.

 

[Turtle]

Very nice turtle, your sprinter, is it a 2500? If so, with all the gear you have onboard, what effect does have on your load capacity?

Very cool set up I'm taking notes!

Thanks. Yes, it's a 2500 Sprinter, model year 2005. As you can imagine, the gear on board reduces the load carrying capacity, pound for pound.

 

[danthewolf00]

how much was one battery? and did you crimp your wires?

 

[Turtle]

83 pounds each wow now thats heavy power!

Yup. All other things being equal, more lead, more weight, equals more amp hour capacity. Each step up within the same footprint is a little heavier a little more amp hours. The Trojan golf cart line, for example, has the:

T-105 - 62 lbs, 220 H
T-125 - 66 lbs, 240AH
T-145 - 73 lbs, 260 AH

Next footprint up is the AC series of J305 batteries:
J305E-AC - 83 lbs, 305 AH
J305G-AC - 88 lbs, 315 AH
J305P-AC - 96 lbs, 330 AH
J305H-AC - 98 lbs, 360 AH

After that is the L16 batteries:
L16E-AC - 100 lbs, 370 AH
L16G-AC - 107 lbs, 390 AH
L16P-AC - 114 lbs, 420 AH
L16H-AC - 125 lbs, 435 AH

EDIT, ADDITION:
Keep in mind these are all 6-volt batteries, and you'll need a pair of them wired in series to make a single 12-volt battery. Every time you wire batteries in series (positive to negative, just like batteries in a flashlight) you increase the voltage, and the amp hour capacity stays the same. When you wire batteries in parallel (positive to positive and negative to negative) the voltage stays the same, but the amp hour capacities of each battery are added together.

Mine is a combination of the two, where the four 6-volt batteries are wired in serial pairs to create two 12-volt batteries of 305 amp hours each, and then those are wired in parallel to give me one large 12-volt battery bank of 610 amp hours. If I had a third pair wired into there I'd have 915 amp hours.

You have to take several things into consideration when deciding on which one you need. Amp hour requirements is the first one, but then you have weight to consider. Also, the Cost Per Amp Hour is a factor, since the dollars rise along with the AH and weight.

Generally, figure out the maximum Amp Hours you'll need between full recharges of the batteries, add 10 percent to that, and then double it to get the minimum size battery bank you'll need. Then look at the total weight of what you've just done, and see if it's too much weight. If it is, then you'll need to make some amp hour requirement compromises or increase the frequency of full recharges.

It's very important that when you start charging the batteries, as with the vehicle's alternator, that you completely charge them before ceasing the charging process. Otherwise you're just chronically undercharging the batteries, which increases sulfation.

Desulfators (PowerPulse, the little black box with the red lettering, to the right of the big red master switch, and another one on the extreme right with the little red LED light on top) help with this somewhat, but fully recharging the batteries each time will dramatically prolong their life. The desulfators really help when you start and stop the engine at shippers, consignees and other places, and the batteries will never be fully recharged between engine starts.

 

[danthewolf00]

you for got to say how much one battery was?

 

[Turtle]

how much was one battery? and did you crimp your wires?

At most distributors, like golf cart places, those batteries are in the $250-$280 range, some are higher. Online they are mostly in the $220 range, plus LTL shipping.

One place online is $185, where I got mine, Staab Battery, at the main location in Hazelwood, MO (St Louis), but they have locations in Springfield and Aurora, IL (will not have the J305's in stock at the other locations, but can get them in 2-3 days when the normal truck run from St Louis takes place).

If you pick them up in person at the main Hazelwood location, they'll probably give you a decent price break. They certainly did for me. Staab Battery is a manufacturing and rebuilding shop buried back in an industrial area behind a steel pipe plant where they don't have many retail walk-ins (that's for sure). When you see the place, it looks like the results of, "I know a guy who knows a guy," kind of thing. They're a distributor and manufacturer of batteries, and they rebuild batteries there and do industrial deliveries. Just looking at the place you'd think it was a cross between a tool and die shop and a storage building, so it's a working place rather than a retail store. But no overhead means a better deal, and the guys in the shop are pretty kewl.

I got mine there for $160 a pop, for four, with core exchange of course. (I didn't forget, just hadn't gotten to it until now )

Yes, I crimped the wires. The cable is X-FLEX® from Cobra Wire & Cable, Inc.®. It's ultra flexible, more flexible than welding cable. I got mine here: Flexible Power Cable

And because it's so flexible (angel-hair type copper strands instead of the thicker wires) it requires special cable lugs. Both Burndy and Panduit part numbers are listed on the size chart at Cobra. The lugs can be found at Graybar, and they are without a doubt the cheapest place for the lugs. No one else was even in the ballpark. A lot of their locations regularly stock Burndy lugs, or they can order the Burndy or Panduit lugs and get them in within a day or two. I used the Panduit lugs. Some locations that stock Burndy lugs may not have the correct part number for the X-Flex cable, tho, so you'll probably have to order them regardless. You can order the lugs with 45 and 90 degree connectors, too, for a better fit depending on the application.

You can get long handled bolt-cutter type crimpers for these sizes of lugs, but they are serious money and as such should only be used by professionals, do not try this at home. Scroll down to the bottom of that page, though, and you'll see a $30 Brute Hammer crimper that works rather well for these large size lugs (larger than #0 cable). The cable stripping tool at the very bottom of the page is gnarly. Way safer than using a knife or something, and works very well. I highly recommend it.

Here's the crimper I used, though, the Ancor Marine Heavy Cable crimping tool. It's a little better than the Brute Hammer tool, but honestly either one will do the job quite nicely.

Here's a video. of how to use the Ancor Marine crimper, sort of. He's crimping a small cable lug, so he can be all gentle-like with that hammer like he's hammering a small nail or something, but for #2/0 Panduit lugs you'll need to really smack that thing hard using a hammer, or, preferably, a 5 lb short handled sledge hammer. And the dood in the vide is a luzer for where he has his left thumb while hammering. Do not do that when using a 5 lb sledge. The crimper has a tension wire that holds it shut, specifically so you can hammer away without having to hold it like that.

 

[Turtle]

Hey Shelled one, what's the deal with the jumper between batteries being smaller than the cable to the bus bar?

A temporary thing, mostly. That size cable is all that is required for those batteries (whatever is required for the inverter), but the reason for them is that the interconnects from the old bank were too short. Or, rather, they were just barely long enough, except that the terminals on these batteries are the "U" type, which is universal. Basically they are automotive posts with bolt holes though the middle.

The large #2/0 cable lugs are big and heavy and have a rather wide tongue, so they only fit certain ways. The flat side of the lug needs to go flush with the terminal, and the interconnects from the previous bank had the tongues mounted in the wrong orientation for these new batteries. You can see the far left black parallel cable, and the far right red one. The flat side of the lugs are on the same side and weren't a problem for the parallel connection, but for the interconnects the flat sides need to be on opposite sides of the cable.

I only had 3 spare lugs, and needed 4, so I went with the standard interconnects. The reason for the large (oversized really) cables is to minimize voltage loss as much as possible. I'll get new lugs and built more interconnect cables next time I'm at the house.

Also, did you fused batteries negitive side at the battery just in case or don't you see the need for that?

No need for it, really. The main battery ground busbar is connected maybe two feet away to the vehicle's chassis, and if it shorts out nothing will happen. You want everything going into and out of the battery fused, which is the positive side. All 12-volt loads connected to the batteries must be fused in the positive lead, but the battery bank itself can be fused in either the positive or negative (ground) line. If you fuse the negative side of the bank, you must still fuse the positive side, however.

One advantage to negative fusing is that the fuse doesn't have to be insulated, which is a small cost savings, and if you have a metal hull on a boat or vehicle and you drop a wrench on the uninsulated fuse it'll just be grounded, anyway.

But with large battery banks, you should be using Class-T fuses, which have a very high arc suppression, to prevent current from blowing a fuse and then just blowing by it in an arc to remake the connection. If you're going to use something like ANL fuses, then fusing both sides isn't a bad idea, but still unnecessary. ANN and ANL fuses have an Arc Interrupt Rating Current of 2700 amps (meaning anything more than 2700 amps and the current will simply blow by the blown fuse to complete the circuit). 2700 is fine for smaller banks.

Class-T fuses have a AIRC of 20,000 amps.

Coast Guard certification and all other electrical codes say positive fusing. One disadvantage of negative fusing is that in the event of a short, 12-volt loads seem to always find a ground somewhere, and if the fuse blows and the short is determined, it'll find another ground in short order and now you're screwed. And you're not just screwed with the total amp hours of the battery bank, you're screwed with the total cranking amps of the bank, which can be significant. In my case the cranking amps of the battery bank is about 4000 marine cranking amps (cranking amps at 32 degrees, versus Cold Cranking Amps at zero degrees). With a negative ground-fused battery bank and having a short take out the fuse, it won't take long for 4000 amps to find a new route to ground, if it wants to bad enough. Class-T fuses prevent that from happening.

 

[Turtle]

What I see when looking at his pictures is not how smart he is about all this battery wizardary, but how neat it all looks. And I know he probably hand crimped those cable connections hisself. To me, I see a work of art here. As someone stated above, turtle could make a living doing this.

Thank you. I am kind of proud of it. I've done a few of these battery installations, mainly in boats. I've seen (and done) messy, and I've seen (and done) neat and tidy, and neat and tidy works way better. Takes some planning, but it's worth it.

Often you'll see battery banks that look messy and complicated, with all sorts of 12-volt loads hanging off the battery terminals. These kinds of installations are hard to work on, and even harder to diagnose problems with.

Other than the battery cables, all I've got connected to them are the connections from the PowerPulse desulfators (one to each 12-volt pair), a temperature sensor that the battery monitor uses, and I have the DualPro charger grounded to one of the batteries (common ground system, so it doesn't matter where it's grounded, as long as it's grounded).

Good use of busbars is key to something like this, or any battery (or bank) where there's more than about one 12-volt load being used.

 

[xiggi]

Is that a Perko battery selector switch?

 

[Turtle]

Is that a Perko battery selector switch?

No, it's a Blue Sea Systems m-Series Battery Switch. Simple ON-OFF switch, since I've got just the one bank.

 

[Moot]

Often you'll see battery banks that look messy and complicated, with all sorts of 12-volt loads hanging off the battery terminals. These kinds of installations are hard to work on, and even harder to diagnose problems with.

I concur! I have added stuff over the years to the point where it is out of control. Way out of control. (WOFC) My next van I will try and duplicate what you have done. I will even add a few extra circuits for future expansion.

Well done!

 

[Moot]

Keep me apprised on how the Dual Pro and desulfators are working.

 

[danthewolf00]

thank you sir as aways you rock!