Crud! My inverter won't power my e-bike charger!

[BigT]

those appear to be 10 gauge wire,  yellow connectors = 10-12 gauge wire.  from the picture the inverters wires seem to be piggy backed with another set of wires.  is that true?  where do those other wires go?

avoid those set screw type terminals like on the battery terminal you posted,  you will be fighting them forever with the wires coming loose.  they use those on a lot of solar controllers,   for what reason I have no idea.  they do not work well in mobile applications or with stranded wire.  BTW only use stranded wire, do not use solid wire.

highdesertranger

The yellow connectors were the largest I could find locally, so I just crammed the #8 stranded wire into them. 

Yes, I piggy-backed the wires from the same terminals that run from the CC to the battery.  The 12V side of the CC.  
It works for small things, like bicycle lights and flashlight batteries, but Christmas day was the first time I tried running something larger since the install.  Still, it's a tenuous connection, and one I never really trusted.  

I guess I'll go do what I should have done the first time.

 

[Seminole Wind]

since you are running with only the starter battery (nothing wrong with that) you want to have some means to prevent your loads (inverter and such...) from discharging the battery to the point you cant start your engine. when you were running the load off the controller, the controller probably had some sort of cut off. your inverter "may" have a low volt cut of, but check and see what it is and make sure if it will leave you enough juice to get the engine started in the worst conditions you get in. some of the inverter cut offs are quite low, like 10 or 10.5 volts. many of the dual purpose batteries that have a few extra amp hours lose some cold cranking amps and can have a harder time starting an engine when run down low.

if the inverter does not provide sufficient protection, i would suggest adding some sort of low volt cut off. you could also still use the load control from the inverter to trip a really that is sized for the the load of the inverter

avoid those set screw type terminals like on the battery terminal you posted, you will be fighting them forever with the wires coming loose. they use those on a lot of solar controllers, for what reason I have no idea. they do not work well in mobile applications or with stranded wire. BTW only use stranded wire, do not use solid wire.

highdesertranger

agreed! they are a pain. over the years i have found a couple things that help.

tinning the tip of the wire, where you solder just the stripped portion of wire. essentially sticking all the strands together with solder to form a solid mass where the wire enters the connection and gets held by the set screw

also, properly mount the controller or what ever it is and then secure the wire withing a few inches of the connection to prevent movement. or having a short secured wire going to a post and nut terminal before continuing can help a lot

 

[BigT]

With your wagan being sine wave and wired with seriously undersized cables, it is quite possible a first step fix (on the cheap) would be to wire it dirrectly to the battery with (much) larger cables. in your situation where the wagan is hard to stuff bigger cables in and you have a long run. (and i assume you are trying to not hurt your pocket book too much) i would hit walmart for some jumper cables. you can get a set of #2 (2 gauge) 20 foot long jumper cables for $20-30. i know these are copper clad aluminum cables but they will carry a boat load of current compared to the 18 gauge copper you have now. and if you use good lugs and heat shrink they will last dang near forever. (i have a similar cable i made in 1992 that looks and tests as if i just made it yesterday) use these cables to run the long distance from the inverter to the battery. put proper lugs on the end by the battery and then use a bus bar and a short section of what ever the largest size wire the wagan inverter will accept. that little short 6 inch or so section will have a tiny impact and the heavy cable will handle the long distance load nicely. if after doing the wire upgrade it still does not work, then upgrade the inverter. the wire up grade would have been needed for the better inverter anyways...

I'm hoping to mount the inverter a lot closer to the battery, say within 6 or 7 feet, and run lighter wires (I hope).  I'm not steadfastly against the idea of running #2 wire, but it would make my life a lot easier, and the project a lot faster, if I could use #6 or #8 wires and leave the bus bar out of it.  

My factory battery terminals have little studs on them that I'd very much like to run the inverter power off, of so I won't have to cut off and replace my battery terminals themselves.

 

[BigT]

your inverter "may" have a low volt cut of, but check and see what it is and make sure if it will leave you enough juice to get the engine started in the worst conditions you get in. 
___________________________________________

agreed! they are a pain. over the years i have found a couple things that help.

tinning the tip of the wire, where you solder just the stripped portion of wire. essentially sticking all the strands together with solder to form a solid mass where the wire enters the connection and gets held by the set screw

Can't I just turn the inverter off when I'm not using it?  I don't run a fridge off it, so it's not on constantly.  I just use the inverter (very rarely) for charging small electronics (laptop, bike lights, razor, and now e-bike charger), and even then only when the engine is running.  Otherwise the power switch is turned off.  

Also, I should clarify my earlier comment about the connections to the CC.  The "screw terminals" are used with crimp-on "fork" connectors, not bare wire stuck into a hole and tightened with a screw.  When not piggy-backed with an additional fork connector, as I have now, they seem pretty secure.

 

[Seminole Wind]

yes, you can be the "low cut off" and if you only run the inverter with the engine running you are probably pretty secure.

but with a 75amp hour battery and a bit of solar you could do quite a bit with out the engine running.
if you go that path you could still manually control the inverter or other load. but sooner or later we end up forgetting or falling asleep and then end up with a dead battery. i cant recall how many times i had to pop start my metro when i ended up watching one too many youtube videos as the battery was getting weak. lol

 

[bullfrog]

Harbor Frieght has a jumper pack on sale for less than $40 which also has a usb port as well as 12 jumper cables and plug. Might be worth considering for emergency starts or maybe even to supliment your system.

 

[BigT]

A couple of years ago I picked up one of those compact jumper kits to keep in the van, but the solar panel seems to keep things nicely topped off when the engine's not running.....  if the sun is shining, anyway.  I've used the jumper a couple of times, but only on other people's cars. 

As for my decision...  I took another look at the available spaces to mount the inverter, and just as I thought, the fender-well where it's currently located, is really the only option.  

So.......  I'm going to leave the inverter where it is and run some #2 battery cables from the engine compartment, 12' to the inverter.  
Somewhere I thought I saw someone suggest that you have to count the length of both the positive and negative cables.  If that's the case, make that 24' of #2 wire.  I hope that's an acceptable distance to run.  

Is there's a smaller gauge wire I could get away with?  Say #6 or #8, if run directly from the battery to the inverter, or would I be right back where I am now?  

If I do go with the huge #2 cables, can anyone recommend a good source for crimp-on, eyelet connectors and in-line fuse holders that will fit over #2 cables, but drop down to a much smaller eyelet size than what you'd normally find on a automotive battery cables?  Not sure what I'm going to crimp those huge connectors with. 

The studs I'm dealing with on both the battery and the inverter are about 1/4".

 

[Seminole Wind]

you should be able to get #2 lugs with 1/4" ring at many auto parts stores. also in alot of cities you can find a "battery store" like interstate has store fronts or a place that caters to golf carts. also check marine supply stores

most of those places can also make the crimps for you.

if you come to the RTR and can wait till then i will have my big crimpers and i bet a few others will be there that can help crimp that size

 

[BigT]

you should be able to get #2 lugs with 1/4" ring at many auto parts stores. also in alot of cities you can find a "battery store" like interstate has store fronts or a place that caters to golf carts. also check marine supply stores

most of those places can also make the crimps for you.

Oh sure, why didn't I think of a battery store?  A friend is NorCal Regional Manager for "Battery Systems".  I should be able to get everything I need from him, and at a good price.  

Kragens is a lot closer, though, so I might start there.  

BTW...  What size fuse should I run between the battery and the inverter?  

Thanks for all the helpful advice!

You can just make out the inverter, mounted to the fender-well, in this photo.  It's about the only open space where I can put it.  

.

 

[Seminole Wind]

there are 2 aspects of choosing the fuse size.the inverter will have a recomended fuse to protect the inverter. and each wire size will call for a fuse size to protect the wire. use the smaller of the 2. first check the specs for the inverter. they should list the recommended fuse. if your wires are large enough to handle that amperage your good to go. my suspicion is if you use the #2 wire you will be fine with the recommended fuse for the inverter.

here is a page with info and a chart
http://bdfuses.com/fusesnwires.php

 

[abnorm]

All the old photos are lost(photobucket)...…….I remember seeing your build photos a while back...….(I've got a BIG Transit)

I'm surprised you can't find another location for the inverter...….and likewise I can't imagine giving up that valuable real estate for the CC

I would think you could find a suitable location on or around the drivers seat...…..Would you miss two inches in front of the seat/pedestal ?
Or behind the seat...…..On the wall...….Dogbox

Or up by the passenger footwell...…..Glovebox...….under your bed


I would also move that CC ……….. UP higher out of the way.....protecting the wire runs in the process

Yeah where are you ?......Lots of us are in Q waiting for the RTR...….. "have-tools-will-travel"

 

[tx2sturgis]

Before you go to all the trouble to run new cables, you could test the inverter (with the ebike charger) right where it is:

Disconnect your solar panels, either at the controller, or wherever it is convenient. 

Pull the fuse protecting those heavy black cables to (or at) the battery, and then disconnect those black cables (which look like 6 or 8 gauge to me) running to the battery from your solar controller. Wrap tape around the positive end while it is disconnected just to be safe.

Remove the short inverter power cables.

Hook those black battery cables up to the inverter, pay attention to the polarity.

Replace the fuse at the battery. You might need a larger fuse.

Power up the inverter. 

Test your ebike charger.

If those cables are heavy enough, the inverter should very easily run your ebike charger.

 

[BigT]

The RTR is happening again already??  I've been a 'little' out of touch.  

No way I can get away for a road trip to wherever it's being held this year.  I assume it's still in Arizona?

I'm just wrapping up a week off, unpaid, of course, for the Christmas break, but Tuesday I have to return to my ball and chain.  
No chance of getting any time off for a while.  We're too short-handed right now and need all the drivers to refrain from calling out.  

Thanks for the offer of help, but I'll get this done on my own, like I always do.     I just need a few tips here and there to make things go more  smoothly.

 

[BigT]

Before you go to all the trouble to run new cables, you could test the inverter (with the ebike charger) right where it is:


If those cables are heavy enough, the inverter should very easily run your ebike charger.

Hey, that's a great idea.  Thanks!

Those black wires are the standard MC4 solar cables.  I think they're either 10 or 12 gauge.

Come to think of it.  If that works, maybe I could forego running more wires, and just use the ones between the CC and battery when needed.  Sure it's not as convenient as having its own, dedicated cables, but I really never use the inverter, so rigging some quick-disconnect plugs or splice that could be easily switched between the two systems, could work.

 

[tx2sturgis]

Those black wires are the standard MC4 solar cables.  I think they're either 10 or 12 gauge.

Ok, but I am referring to the cables that feed from the controller to the batteries. Whichever those are, use those, NOT the solar panel cables. Those solar panel cables have a 600-1000v insulation rating, so yes, they look like a heavier gauge wire in the pics.

 

[BigT]

Ok, but I am referring to the cables that feed from the controller to the batteries. Whichever those are, use those, NOT the solar panel cables. Those solar panel cables have a 600-1000v insulation rating, so yes, they look like a heavier gauge wire in the pics.

Well, I went ahead and used the MC4 solar cables that run, part way, to the battery.  At some point I spliced #8 wire the rest of the way to the battery and a blade fuse.  It worked fine!    The charger ran like it's supposed to!  Hopefully the fact that the e-bike battery was already fully charged didn't have any real effect on the results...  :-/  (I'm not sure if chargers have to work harder when charging completely dead batteries).  

You know, there was a time, and not that long ago, that I would have thought of that idea by myself, but I fear the work I do is softening my brain and lowering my IQ.  
Before long I'll look just like my avatar photo.  

When you drive back-and-forth all day, over the same roads, day in and day out, 'till you start looking for places in the rig to throw a rope/noose over, it can have detrimental effects on your mind.  People always think I'm joking when I say "The longer I work here, the dumber I get."  Sadly, it's no joke.  

OK, so, cool!  Maybe I *can* get away with running more of the #8 wire and connectors I have in abundance, and not have to run out and buy heavier gauge, automotive battery cable.  I do like the location I currently have the inverter mounted, and moving it to under the seat or footwell would only save me about 4', but I'm not opposed to moving it if I have to.

 

[bullfrog]

Pretty is okay as long as it works!

 

[BigT]

I'm not worried about what it looks like, I just know that finding 6 or 8 gauge wire and connectors is a lot easier around here than the #2, automotive stuff. It's also a lot easier to route/run through the van.

Not trying to cheap out, I just want to keep things as simple and stress free as possible.

 

[tx2sturgis]

Well, I went ahead and used the MC4 solar cables that run, part way, to the battery.  At some point I spliced #8 wire the rest of the way to the battery and a blade fuse.  It worked fine!    The charger ran like it's supposed to!  Hopefully the fact that the e-bike battery was already fully charged didn't have any real effect on the results...  :-/  (I'm not sure if chargers have to work harder when charging completely dead batteries).  

Great!

And yes, the ebike charger will pull more or less the same while charging, from empty to full, and when the ebike battery is fully charged the ebike charger will go into standby and pull almost nothing. So you need to do your testing with the ebike battery low enough to take a charge from the ebike charger. 

I think 6 or 8 gauge wire will easily handle your inverter under this load condition, the ebike charger is probably pulling about 160 watts. (52v x 3A + overhead).

That's roughly 12.3 amps at 13 volts, lets call it 15 amps with overhead and slight efficiency losses.

If this all works, and I'm guessing it will, it should be a lot easier to afford and route 8 gauge wire. 

Be sure you use a suitable inline fuse. 20-25 amps should be in the ball park.

Keep in mind that amount of current being pulled from your starter/deep cycle battery must be offset with solar or running the engine.

 

[BigT]

Keep in mind that amount of current being pulled from your starter/deep cycle battery must be offset with solar or running the engine.

I was able to put a little bit of power into the e-bike battery before the green light came on and the charger went into standby, so I know it was able to run it.  

You know, I've never run the numbers on solar vs battery use.  I always looked to Sternwake for that sort of thing.  

I've got 190 Watts of solar going in, but of course no real idea of what's going out with particular items.  

I have a "Endless Breeze" 12V fan that I know only draws 1 Amp on low, so I always figured my panel was pumping more in than I was losing..  At least when the sun was overhead.  

I really don't know how long I could run the inverter with the battery charger plugged into it, if the engine wasn't running and I was counting on the 190W alone.  Fortunately I don't have a problem idling my engine for extended periods of time.  

The idea is to charge the e-bike battery while in-route between distant riding locations.  But idling in a camp spot or parking lot is fine too.