Lithium Install on an E19

[GoldenSloth]

Starting this thread as much to document my install as to share with others, but I’m excited about the progress so far today. I dare say, the hard (heavy) part is done! 4x 300Ah Epoch Essential batteries with their matching mounting plates in place.

Next is to decide if I’m going to wire them to bus bars or just interconnect the bank and then measure for wire length.

 

[jjdeluca]

Wow - 1200Ah of batteries!

 

[Ron in BC]

Maybe he's going to have electric floor heating like Johnny Hung.

Ron

 

[RambleOn]

More power to you @JS302706 !! We have a mere 920ah in ours. If it helps, attached is the recommended wiring for 4 batteries in parallel, with the total positive and negative connector lengths equal, as you mention. Enjoy!

 

[GoldenSloth]

Measurements were made and it looks like 18” is a touch over my longest interconnect length. I went with 2/0 wire which is supremely overkill for my no-inverter trailer, but I won’t have to do it twice if I add an inverter down the road. I’m going to be doing a simple “diagonal” connection method, as Victron calls it. So I’ve got sets 4 of equal length 18” 2/0 from Windy Nation en route. The 4th set is to go from 4th battery of the bank’s negative to the shunt, and the positive from the 1st battery to the fuse block I’m adding (mentioned below).

Escape had 3x 8awg positives wired to the stock lead acid. I’m going to fuse each of those individually at 40 amps using a Blue Sea MRBF fuse block (5196). I’m sure it’s fine to just do what they had from factory, but I like having a fuse before the wire run out of the passenger side dinette seat.

Hopefully I can make some more progress early next week!

 

[GoldenSloth]

Maybe he's going to have electric floor heating like Johnny Hung.

Ron

I’m WAY too lazy to do heated flooring or add more than the 600w of Escape-provided solar on the roof. His solar setup is really slick.

 

[John in Santa Cruz]

my 2 x 206AH, I ended up wiring each to its own fuse and tied those fuses to a positive (and grounds to a negative) bus terminal, like this:

those are 100A fuses, but I ended up replacing them with 150A when I added the inverter (which gets its DC off the same + and - bus bars. The cutoff switch on the upper left is for the solar panels connection to the MPPT...

 

[CE Vogel]

Wow! That is a lot of energy! A very tidy installation, too. With this much energy storage, a small glitch could easily become a big problem. I suggest you install a fuse at each battery, that way if one battery fails, the other batteries won't keep feeding into the failure. The size of the fuse is up to you, but should not be greater than the BMS rating. Here is one suitable fuse: https://www.waytekwire.com/catalog/fuses/bolt-down-fuses/eaton-s-bussmann-series-mrbf-100-marine

 

[GoldenSloth]

Wow! That is a lot of energy! A very tidy installation, too. With this much energy storage, a small glitch could easily become a big problem. I suggest you install a fuse at each battery, that way if one battery fails, the other batteries won't keep feeding into the failure. The size of the fuse is up to you, but should not be greater than the BMS rating. Here is one suitable fuse: https://www.waytekwire.com/catalog/fuses/bolt-down-fuses/eaton-s-bussmann-series-mrbf-100-marine

Yeah, I’m using an MRBF on each positive terminal, you can see two of them in the photo, the other two will be going on when I do wires. They’re 250A fuses, the BMS can handle 400 surge loads but nothing I have should require remotely that much energy, so I’d rather a fuse fail sooner.

 

[John in Santa Cruz]

fuses should be sized for the smaller of the wiring downstream of the fuse, or better than the max expected load, and gee, the wiring had better be better than the max expected load. I'm happy to admit I really should replace some of the primary battery wiring on my rig, I even have the AWG 2 wire and terminals to redo it (I used AWG 4 originally not expecting to have a 2000W inverter in the mix). I used AWG 4 originally and its probably good enough.

BTW, for anyone doing large gauge DC wiring, I've been very happy with the WindyNation brand pure copper fine strand stuff I've found online. The insulation is quite tough, the wire is true to gauge and high quality pure copper fine strand cable. big gauge pure copper wire is effin expensive, but bad wiring == fires.

 

[GoldenSloth]

Yep, the fuses within the bank (250A) are undersized for the 18” 2/0 interconnect wire from WindyNation which arrived today — woo!

The bank will feed this BlueSea fuse block, with 40A fuses, that connects to the 3x 8AWG wires Escape had attached to the stock Pb battery.

The fuses on the battery terminals are likely overkill but will make me sleep better. Likewise, I could have put these on a bus bar with a single fuse between the bus bar and battery bank, but I’ve at least got fault isolation this way, too. I don’t think I’ll blow any of the 40s given I’ve only got 600 watts of solar on the roof and am using the stock WFCO WF-8955-AD-WAGO as the converter/charge. While theoretically (no losses) they could support a 50A load, I’d be surprised if a 40 blew. And, like John said, I sized the fuse to the 8AWG Escape installed. We’ll see if I need to change wiring that in the future.

Hopefully I can make some more progress tomorrow after work if I get another little bike project finished up first.

 

[zephirus]

How did you secure the batteries down? Strap over the top and then screw directly to the floor? Or do you have some gizmo/tray?

 

[RambleOn]

I don’t think I’ll blow any of the 40s given I’ve only got 600 watts of solar on the roof and am using the stock WFCO WF-8955-AD-WAGO as the converter/charge. While theoretically (no losses) they could support a 50A load, I’d be surprised if a 40 blew.

Just FYI, we use the 55a WFCO and it delivers 54a through ~18’ of 1/0 wire from its location in the front of the camper to the batteries in the back. Not sure if that affects your fusing plans or not but thought I’d put it out there.

 

[GoldenSloth]

How did you secure the batteries down? Strap over the top and then screw directly to the floor? Or do you have some gizmo/tray?

I used the trays Epoch sells. The price seemed high at $40 each but it did make the install easy since it came with straps and screws.

 

[GoldenSloth]

Just FYI, we use the 55a WFCO and it delivers 54a through ~18’ of 1/0 wire from its location in the front of the camper to the batteries in the back. Not sure if that affects your fusing plans or not but thought I’d put it out there.

Very good to know. I don’t get why Escape chose to use 8AWG on that connection. Unless, of course, I misread the insulation marking. I’ll double check that later.

 

[RambleOn]

I doubt you misread it. They seem to undersize quite alot.

 

[John in Santa Cruz]

How did you secure the batteries down? Strap over the top and then screw directly to the floor? Or do you have some gizmo/tray?

in my install, shown above just off the left, I used 4 pieces of aluminum 1" angle, screwed to the floor, and the end two slotted for a battery clamp strap.

ignore the fuse holder I'm posing here

these have held firm for 3 years now of rough roads.

 

[zephirus]

I used the trays Epoch sells. The price seemed high at $40 each but it did make the install easy since it came with straps and screws.

Thanks ! These? Premium Trays for 50ah Epoch Lithium Batteries These look very nice.

 

[GoldenSloth]

Thanks ! These? Premium Trays for 50ah Epoch Lithium Batteries These look very nice.

My batteries used these: Battery Tray for Epoch Essentials 12300A-H

But, honestly, John's post above would also work if you're looking to be a bit more budget friendly IMO. I did like how easy the trays made for my layout and install, though.

 

[CE Vogel]

Very good to know. I don’t get why Escape chose to use 8AWG on that connection. Unless, of course, I misread the insulation marking. I’ll double check that later.

The 8AWG wire was barely adequate for the lead-acid batteries since they only accept a high charge for a few minutes, then tend to self limit as the charge increases. Your 40A fuse is probably fine for the lead-acid batteries. Lithium batteries, as I suspect you know, will take full charging current until they are fully charged. With the size of your battery bank, the WFCO could be putting out full current for hours, and that 8AWG wire will get very hot if the fuse doesn't blow. You could double the 8AWG wire to the WFCO, or replace it with 4AWG or larger wire, and install a 80 - 100 amp fuse to take full advantage of the charging capabilities of your WFCO charger.
My PD4560 converter charges my 300AH of lithium batteries through 20' of 4AWG wire. The voltage loss through that wire limits charge current to about 30A into the batteries. Bigger wire is better!