Running the Elk off a deep cycle battery array

Quixote_1

Quixote_1

Active Member
Would there be any drawback of backing up the Elk M1-Gold off of an array of deep cycle marine batteries if the batteries are properly charged and ventilated?
I don't see why I would want to use a sealed lead battery that is only good for 8AH if I am already going to use an alternative power backup that amounts to a few hundred AH. Can anyone bring to my attention any dangers or shortfalls of such a method?
Thanks!
 
The M1 has a built-in battery charger, I suspect you need to disable that - perhaps a blocking diode would be sufficient.
 
Connect the marine batteries to the battery input on the M1. Use a separate battery charger for the marine batteries. Disconnect the plug in 16.5 volt transformer. There is a program option to disable the AC failure. I will have to look up where the program option is at.

The marine batteries could draw too much current to recharge them from the M1's power supply, so that is the reason to use a separate high current power supply to recharge the marine batteries. You will probably need a 5 to 10 amp 14 volt regulated power supply. This will provide a float voltage to keep the marine battery charged up.
 
If you use a separate charger, I highly recommend a Battery Minder. The thing constantly desulfates the battery, your battery will last nearly forever on it. I have two of them that I use to bring heavily sulfated batteries back from the dead (about 3-4 months on a typical car battery brings it back to almost 100% capacity as long as the plates aren't shorted).

I don't see how the marine batteries would draw more current to charge, unless the internal resistance was considerably lower than the standard 8Ah battery. I would think with most batteries, regardless of the size, it would just draw the same current for a longer period of time to get the thing topped off.

If anyone is looking for a good battery that doesn't require venting, AGM batteries are the way to go. Optima used to be awesome, but I've had some bad experiences with them over the last couple of years. I've just started buying Odyssey batteries. If you're put off by the price, Sears Diehard Platinum are rebranded Odyssey AGM batteries and are cheaper than getting the ones with the Odyssey name on them. The Odyssey for my truck was $270, and the rebranded sears version was $180. Many people are using the Odyssey motorcycle batteries in their cars to reduce weight.
 
Wow! Thanks for all of the useful information. You guys are awesome!

I'm not sure I'm following you, though, Spanky. You mentioned "Disconnect the plug in 16.5 volt transformer." I've only just ordered my Elk, so I am unfamiliar with the system for now. Can you please elaborate and explain what disabling the AC failure would achieve? Are you saying that I should run off of the battery constantly and charge the battery constantly as well? I suppose the system would then run off of the charger until the AC fails, at which point the battery would take over?
 
By disconnecting the 16.5 volt ac transformer you are now running on DC power only. Because you have disconnected the AC transformer you will get an AC Power Loss alarm from the elk panel disabling it will be necessary to avoid the nuisance false alarm. As long as the charger for the marine batteries has enough current to handle the load and keep the batteries charged there will be no need to power the elk with AC power. Make sure your charge has provisions built in to not overcharge the marine batteries. Depending on your total battery capacity and current draw you will probably see the charger cycle from maintenance/standby to charge several times a day.

You are creating an on-line UPS:

http://www.pcguide.com/ref/power/ext/ups/typesOnLine-c.html
 
Can you damage the ELK by running it off DC power higher than 12V? I know everything has tolerences, but I know some have mentioned to have the batteries connected an an external 14V power supply. This would then be in parallel with the ELK panel, and essentially running the ELK at 14V (or more depending on the charger). I dont know what the ELK can handle, but figured it may be worth bringing it up.
 
Also make sure you install an appropriately sized fuse as close to the positive terminal on the battery as possible. Having a longer wire run since you can't mount the battery close to the panel will increase the risk of a short. A fuse might save your house from burning down.
 
signal15 said:
Also make sure you install an appropriately sized fuse as close to the positive terminal on the battery as possible. Having a longer wire run since you can't mount the battery close to the panel will increase the risk of a short. A fuse might save your house from burning down.
Click to expand...

That brings up a good point...does anyone add an inline fuse at the battery in the "normal" setup, i.e., the battery is within a few inches of the control? I know chances are remote, but I've had wires pinched (not bad enough to cut the insulation, though) in the enclosure doors.
 
Ira said:
signal15 said:
Also make sure you install an appropriately sized fuse as close to the positive terminal on the battery as possible. Having a longer wire run since you can't mount the battery close to the panel will increase the risk of a short. A fuse might save your house from burning down.
Click to expand...

That brings up a good point...does anyone add an inline fuse at the battery in the "normal" setup, i.e., the battery is within a few inches of the control? I know chances are remote, but I've had wires pinched (not bad enough to cut the insulation, though) in the enclosure doors.
Click to expand...

I don't have one on mine right now, but it's mounted very close to the panel. The UL requirements say that your battery must be mounted within so many inches of the panel, probably because of the risk of a short. However, I'm going to move mine away from the panel, and I will definitely put in a fuse. IMO, one should be included anyway.
 
signal15 said:
Ira said:
signal15 said:
Also make sure you install an appropriately sized fuse as close to the positive terminal on the battery as possible. Having a longer wire run since you can't mount the battery close to the panel will increase the risk of a short. A fuse might save your house from burning down.
Click to expand...

That brings up a good point...does anyone add an inline fuse at the battery in the "normal" setup, i.e., the battery is within a few inches of the control? I know chances are remote, but I've had wires pinched (not bad enough to cut the insulation, though) in the enclosure doors.
Click to expand...

I don't have one on mine right now, but it's mounted very close to the panel. The UL requirements say that your battery must be mounted within so many inches of the panel, probably because of the risk of a short. However, I'm going to move mine away from the panel, and I will definitely put in a fuse. IMO, one should be included anyway.
Click to expand...
I do not either.
I am thinking the UL thing is having to do with Non-Power Limited wiring. Putting a fuse near the battery changes this, I believe. Someone please to elaborate?
 
signal15 said:
Ira said:
signal15 said:
Also make sure you install an appropriately sized fuse as close to the positive terminal on the battery as possible. Having a longer wire run since you can't mount the battery close to the panel will increase the risk of a short. A fuse might save your house from burning down.
Click to expand...

That brings up a good point...does anyone add an inline fuse at the battery in the "normal" setup, i.e., the battery is within a few inches of the control? I know chances are remote, but I've had wires pinched (not bad enough to cut the insulation, though) in the enclosure doors.
Click to expand...

I don't have one on mine right now, but it's mounted very close to the panel. The UL requirements say that your battery must be mounted within so many inches of the panel, probably because of the risk of a short. However, I'm going to move mine away from the panel, and I will definitely put in a fuse. IMO, one should be included anyway.
Click to expand...

Not sure where you are quoting the "UL Requirements" for the battery to be within inches of the panel. If you are referring to the ELK instruction manual then I think you are interpreting the method that ELK chose to comply with the NEC requirement to seperate the power limited and non power limited wiring. Elk chose to make it as easy as possible for the installer and laid out their panel to have the battery terminals away from all other terminals so the battery wires can be routed to the battery without coming within the 1/4 inch of the power limited wiring.

The NEC states that Power Limited Wiring shall be segregated from Non Power Limited Wiring by a minimum of 1/4 inch through air spacing. UL985 bascially states you have to comply with that.

FYI another method for complying is to use a barrier over the Non Power Limited Wiring such as UL Recognized Component Heat Shrink or Extruded Tubing.

I am familiar with the above because I was the UL Engineer at the time that verified the compliance of the above with ELK. Since the M1 is laid out very well the compliance was easy.

In regards to the fuse that is a seperate but similar issue and it very important to use an appropiately rated fuse. On a 12 V circuit if you add a maximum 5 amp rated fuse the circuit would then be considered "Class 2" (not Power Limited) and would have a reduced risk of fire.

Short circuit current on a 7 aH battery is nearly 100 amps. On larger batteries you can almost weld with them.
 
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