Favorite Battery Monitor System?

[Squatch]

Volt meter just doesn't tell the whole story. A lot depends on the battery. I've been using Optima's in my boat for years. When fully charged they are at 12.7-8 volts. When my Powersonic deep cycle gets down to 12.7 I'm at 91%!!! Normal for this battery is 13.4-5 volts at 100%. The ability to customize the charge profile with the Bogart stuff counts for a lot with me.

After a lot of homework and reading I don't think that MPPT is really that much better on a small 12 volt system. It seems this stuff comes into it's own when using 48v panels and such.

 

[rando]

I think all the units being discussed here have the ability to customize both the charge (and discharge for the monitors) profiles. I agree that MPPT doesn't buy you a whole lot, realistically 10 - 20%, but as the MPPT controllers are now essentially the same price as quality PWM chargers, there is not much reason not to use MPPT.

 

[Esus]

Do you have any pictures of how you mounted your controller? Thanks.

I posted a pic of the LED guage earlier in this thread. Here is the electrical setup with battery, controller, shunt, etc:

There is a mistake in this photo - the negative from the controller should go to the shunt, not the battery. My BMV was unaware of any charging from the array until this was corrected.

Also, the MPPT controller is technically supposed to be mounted horizontally, though I haven't had any issues with it as such.

 

[Vic Harder]

I made the same mistake when wiring mine up too... followed the instructions for both devices, just didn't think about putting the two together. Rando straightened me out quick though...

I wonder about the horizontal mounting too. Heat/air flow is their concern I think. I see you have standoffs to get airflow underneath? I've checked the temp of the unit a few times when charging, not even warm, so not worried yet.

 

[Esus]

I made the same mistake when wiring mine up too... followed the instructions for both devices, just didn't think about putting the two together. Rando straightened me out quick though...

I wonder about the horizontal mounting too. Heat/air flow is their concern I think. I see you have standoffs to get airflow underneath? I've checked the temp of the unit a few times when charging, not even warm, so not worried yet.

Glad I'm not the only one!

Yep, added the standoffs for a bit more air flow. I've checked it several times, especially when the camper is in full sun and PV array is cranking. It doesn't even get warm. Which is good because this really was the best way to mount in my particular space/setup.

 

[ckent323]

Eric/VIc, et al,

1) What did you use for standoffs and how thick?

2) Other than airflow does orientation matter for the Victron controller,etc (not including batteries)? - I don't think so but wanted to be sure


3) Grounding question: At this juncture I don't intend to connect the camper to the truck electrical system. I have been running without a ground to the truck for years and have used shore power and generator to keep the batteries charged with no apparent problem (never really thought about it much). What are your thoughts?

In regards to Eric's question about the capacity of the Victron 75/15 if I need to add panels: I looked at both the present solar system (200 W) as well as the the likely size of an upgraded system if needed which would be 300 W - 400 W.

An upgrade to even 300 W would certainly exceed the capacity of the Victron 75/15 and when connected in parallel would slightly exceed the capacity of the Victron 100/30 by a couple of amps.

So the addition of more panel watts would either involve replacing the 75/15 with a 100/50 ($295 or 3x the cost of the 75/15) or adding another 75/15 (which was Vic's approach). I decided that I would just add another 75/15 when/if the time comes (I got mine from PKYS for $88.40).


Regards,
Craig

 

[Esus]

Eric/VIc, et al,

1) What did you use for standoffs and how thick?

2) Other than airflow does orientation matter for the Victron controller,etc (not including batteries)? - I don't think so but wanted to be sure

3) Grounding question: At this juncture I don't intend to connect the camper to the truck electrical system. I have been running without a ground to the truck for years and have used shore power and generator to keep the batteries charged with no apparent problem (never really thought about it much). What are your thoughts?

I believe I added four or five washers to each mounting point. Simple and cheap.

I have no idea why they mention in the instructions to mount vertically. Only thing I could think of was heat. I was trouble shooting something with a Victron support guy and mentioned the orientation to him in an email and he said it didn't really matter.

I'm not grounded beyond the camper itself. I'm not sure what the stock ground bus is grounded to but it's probably the frame which is fine.

 

[Vic Harder]

I used 1/2 alum tubing for my standoffs. Vertical alignment allows air to flow more readily under over the heat sink. If you can do it that way, it is better. Here is how I laid out my panel.

And mounted inside the battery box

If you ever want to get another 75/15, let me know. I want to upgrade the roof MPPT controller to a 30 amp unit.

I ran a 4g cable to the camper frame as my ground in the camper.

That said, I have yet to deploy my portable panels... maybe this fall camping in the Canadian Rockies?

 

[Esus]

Great looking setup Vic