SurePower 1314/1315 vs. "battery switch"

[natjwest]

Is there any reason not to use the SurePower 1315? I'm going to get solar at some point in the future, so the 1315 would be able to allow current through to the starting batteries instead of the 1314 which only goes from alternator to aux battery.

I can't believe how hard it is for me to understand all these products. I've read zillions of threads online, but still don't get it. I'll explain what I want to do.

I have a diesel with two batteries and one alternator. I would like to plug in my FWC to the truck via a 2-prong plug in the bed. This plug will go to the SurePower and then to the main battery. Is this all correct?

To complicate matters, I would occasionally like to run my camper off the truck's batteries, as well as start off the camper aux battery in a pinch. It doesn't seem that the SurePower will allow that and that I would need something like this product instead:
http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=17251&catalogId=10001&langId=-1&storeId=11151&storeNum=10109&subdeptNum=10548&classNum=10597

Am I right in that thinking?

 

[UglyScout]

You need the 1315-200. It has the bi-directional flow you need and has the provisions for a switch to put both batteries together for starting.

If you are going to ever us the camper battery to assist in starting - make sure you use large enough battery cables to handle the load. Your diesel starter with suck the amps and melt undersized wire in a hurry...

 

[pods8]

In the pinch you want to try and start of your axillary batteries I'd just use jumper cables and not worry about trying to hard wire that option.

You could use a battery switch to move the camper draw over to the starting batteries if you want or see if you can manually override whatever separation method you have employed.

I run a charger with a remote input that is on an ignition hot line to turn it off/on between my truck and camper batteries. Normally when the truck is off the circuit is broken. However there is a switch to override that and then the camper batteries would start pulling a charge off the truck batteries even with the vehicle off. However if my system the axillary batteries need to be functioning/present still. Are you trying to set up in case you kill the axillary batteries totally?

 

[K6ON]

Is there any reason not to use the SurePower 1315? I'm going to get solar at some point in the future, so the 1315 would be able to allow current through to the starting batteries instead of the 1314 which only goes from alternator to aux battery.

I can't believe how hard it is for me to understand all these products. I've read zillions of threads online, but still don't get it. I'll explain what I want to do.

I have a diesel with two batteries and one alternator. I would like to plug in my FWC to the truck via a 2-prong plug in the bed. This plug will go to the SurePower and then to the main battery. Is this all correct?

To complicate matters, I would occasionally like to run my camper off the truck's batteries, as well as start off the camper aux battery in a pinch. It doesn't seem that the SurePower will allow that and that I would need something like this product instead:
http://www.westmarin...&classNum=10597

Am I right in that thinking?


Natjwest, I use nothing more than a Perko marine battery combiner switch in the camper.I use the simple Perko switch from West Marine part # 281469 for mine. It has 4 positions: Battery 1, Battery 2, Both, Off. This allows me to run the camper on a combo of the truck and camper batteries, camper battery only, or truck battery only. When switch is in the “Both” mode then the truck and camper batteries are in parallel, and, of course the camper batteries help start the truck. I generally leave everything in parallel on “Both” setting. If you really want the camper battery to help start the truck, then you’ll need heavy cable from the truck batteries back to the camper.

There’s a 10 amp multi stage marine battery charger in the camper. When I’m hooked to shore power everything is getting topped off by the charger. I ordered a 100 watt solar panel (http://www.amsolar.com/rv100.html) but haven't installed it yet. I'll probably just run the camper on it's own batteries once the solar is installed.
Even more confused now ?

 

[pods8]

If you really want the camper battery to help start the truck, then you’ll need heavy cable from the truck batteries back to the camper.


You'll need heavy cable as well if you ever run one set of batteries down and then turn it to "both" because when they go in parallel they will quickly try to equalize.

 

[ntsqd]

I see it as there are several types of control systems available:
Manual.
Fully Automatic.
Fully Automatic with a manual over-ride.

It sounds like you want the last type of system. Unfortunately there are nearly as many ways do this as there are people doing it. Within that type there are integrated systems and assembled from components systems. Some of these have a remote control, others do not.

Smart solenoids (Automatic Charge Relay, "ACR"; Voltage Sensing Relay, "VSR" & similar) have nearly taken over the automatic market from diode bridges. That isn't a bad thing, but I digress. Some are "single sensing" in that they only look at the voltage of one battery or battery bank, others are "dual sensing" and look at the voltages of both batteries or battery banks. Single sensing will only turn on when the battery monitored has reached some threshold voltage. Dual sensing will turn on when either battery/bank has reached that threshold. With the prospect of solar in the future I would suggest only looking at the dual sensing versions as it would be nice if once the house batteries were topped off that the solar or on-board inverter/charger could then top off the truck batteries too.

Some smart solenoid mfg's have included a remote control switch to turn on the solenoid regardless of battery voltage. Be careful of the solenoid's current rating with this. Some can stand starting currents, others can not. As has been pointed out, to enable starting off of the camper battery the cables from/to it will need to be large enough to handle starting currents over that distance. If you instead opt to carry jumper cables to fulfill this function then those need only be wires big enough to carry the alternator's maximum output over that distance, plus a little safety margin. That is likely a significant difference in both weight and in cost of wire/cable and related components.

The smart solenoids that I am familiar with (all two of them) only have the two stud connections plus a reference grounding wire. Because of that they can go anywhere convenient in the wire or cable from the alternator/truck battery(ies) to the camper battery(ies). You may want it under the hood or in the camper, but it is not restricted to either place, only to someplace protected.

If being able to flip a switch to self jump-start is what you really want then there are two ways to go. A smart solenoid with a switch (remote or not) that can carry starting current, or a smart solenoid that can not carry starting current combined with some sort of manually activated switch or solenoid that can carry starting current.

My own choice was to use BEP Marine's VCR combined with a marine battery bank switch. Fully automatic until I need it to be fully manual. If/when that situation arises opening the hood to access the switch isn't a big deal to me, but some want control of that function in their dash.

 

[natjwest]

Natjwest, I use nothing more than a Perko marine battery combiner switch in the camper...
...
Even more confused now ?

Actually I am totally less confused now, you did a great job explaining it and I think I'll do your way. Leaving it in "both" is an idea I hadn't really thought of. But what the hell is this unit? What does that other box, the 7610 Automatic Charging Relay (ACR), do?

http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=17251&catalogId=10001&langId=-1&storeId=11151&storeNum=10109&subdeptNum=10548&classNum=10597

 

[UglyScout]

It appears to be an automatic 'isolator/relay' box - they call it an ACR- much like the 1314/1315.

 

[HERR42]

it just does not seem prudent to expose the campers electrical system to the vehicle starting system.

while i understand the thought that "there is a spare battery there, take advantage" i dont see how you
can do it without providing an adequate current path i.e. big cables. big.....

exposing the camper battery to a hungry starter is really going to be a problem.

on the other hand, allowing the campers solar or converter to charge the truck batteries is a noble pursuit.

 

[UglyScout]

on the other hand, allowing the campers solar or converter to charge the truck batteries is a noble pursuit.


But if you don't use the truck batteries to power the camper -- why would you need to add additional charge to the truck? My trucks alternator seems to make plenty of power to keep things charged up.

The added complexity to wire the truck and camper batteries toegther (suitable for any serious ampeage) doesn't seem worth it to me. A simple one-way automatic isolator seems plenty for me.

 

[craig333]

Natjwest, I use nothing more than a Perko marine battery combiner switch in the camper.I use the simple Perko switch from West Marine part # 281469 for mine. It has 4 positions: Battery 1, Battery 2, Both, Off. This allows me to run the camper on a combo of the truck and camper batteries, camper battery only, or truck battery only. When switch is in the “Both” mode then the truck and camper batteries are in parallel, and, of course the camper batteries help start the truck. I generally leave everything in parallel on “Both” setting. If you really want the camper battery to help start the truck, then you’ll need heavy cable from the truck batteries back to the camper.

There’s a 10 amp multi stage marine battery charger in the camper. When I’m hooked to shore power everything is getting topped off by the charger. I ordered a 100 watt solar panel (http://www.amsolar.com/rv100.html) but haven't installed it yet. I'll probably just run the camper on it's own batteries once the solar is installed.
Even more confused now ?


I run mine the exact same way. Been working perfectly for six years now. And its only 10 guage wire to the camper from the truck.

 

[natjwest]

I run mine the exact same way. Been working perfectly for six years now. And its only 10 guage wire to the camper from the truck.

Thanks, craig. It's good to hear 10 ga is working for you. I'd rather not mess with 4 or less.

 

[pods8]

I run mine the exact same way. Been working perfectly for six years now. And its only 10 guage wire to the camper from the truck.


What type of battery are you running in your truck and how often (if at all) have you had to replace it?

I just don't see anything good coming out of running a truck starting battery in parallel with camper deep cycles. The normal truck battery isn't made for deep cycle use. Now if you're running optimas or something in the truck they are built a bit more for that service.

 

[HERR42]

What type of battery are you running in your truck and how often (if at all) have you had to replace it?

I just don't see anything good coming out of running a truck starting battery in parallel with camper deep cycles. The normal truck battery isn't made for deep cycle use. Now if you're running optimas or something in the truck they are built a bit more for that service.



and i dont understand how the wiring doesnt fry when you hit the starter....with the camper in parallel.
luck?

 

[UglyScout]

and i dont understand how the wiring doesnt fry when you hit the starter....with the camper in parallel.
luck?


I would guess it is part luck and part the fact that the main truck battery is never discharged enough to require much 'help' from the camper battery. If the truck battery were discharged low enough and the camper battery were fully charged and you hit the starter I could see wires melting.

I've seen #8 melt as an alternator tried to recharge a mostly dead battery - and alternators usually top out at 150 amps - where as you starter may hit as much as 250-300 amps!

 

[HERR42]

my point exactly!

in addition, the 30 amp thermal breaker should trip....maybe it is all the time and no one knows?

 

[craig333]

I run an optima in the camper. Basically for an overnighter I'm not concerned, I'm just not using that much juice. For a longer trip I"ll isolate the camper battery from the truck.

My truck batteries are due for replacement. Noticeably harder starting now. They have seven years on them so no complaints here.

 

[craig333]

I may just go out and toss my ammeter in between the camper and the truck and see just what it does when I start the truck. Its never tripped the breaker.

 

[HERR42]

I may just go out and toss my ammeter in between the camper and the truck and see just what it does when I start the truck. Its never tripped the breaker.



how would you know? its thermal...it would reset on its own.

i sure would like to see the results!

 

[ntsqd]

The whole starting deal is part of why I have the VSR/ACR. Can leave the aux bank isolated at the battery switch, but still have the alternator charge it while running. If you go with the "dual sense" version of these units then any solar input will close the circuit and top off the starting battery. This last feature isn't so important while camping, but is a real bonus when the vehicle sits for long periods between uses because then the solar can keep the stating battery(ies) topped off against the little draws (computer memory, clock, etc.) that all late models have.