25 replies to this topic

[ExplOregon]

Hi Vic,

 

My battery is a Deka Intimidator Group 24 79aH AGM.

It's what was factory installed from FWC.

 

Regarding number 3, ya I was also wondering about that. You bring up a good point. I might need to re-sync after a full charge. Since the solar panel isn't hooked up when in storage/parked, I also have a Noco Genius 10 wired in to charge and then maintain my battery when parked. I've noticed that charging from the alternator doesn't get me back up to 100% SOC even after a long drive. It will get in the 98-99% range. So I just use the Noco to top it off and maintain.

 

I haven't plugged in the Noco unit since installing the MPPT. For a test, this weekend though, I drew the battery down to 94% then plugged in the solar panel to see: 1) how many watts it would bring in on a sunny day at noon 2) how quickly it would charge the battery 3) if it could get the SOC to 100%.

 

Regarding test 1: at the beginning, it was pulling in ~90Ws in full sun. There were big clouds coming in and out so the wattage was jumping around a bit.

 

Test 2: the panel was able to get the SOC to 99% in about 1.5hrs. I noticed that MPPT switched from bulk to absorption. At that that point, the cloud cover was constant and I was pulling in about 8-12W, which sounds about right given the cloud cover and the switch to absorption from bulk state.

 

Test 3: I ended up having to leave and couldn't leave the panel laying out so I wasn't able to see if the panel would get the SOC to 100%.

 

Sounds like I should draw the battery down again, but this time, plug the Noco unit it to bring it back up to 100% and then do a re-sync.

 

Sidenote: I accidentally left the kill swtich/power knob on overnight. The SOC dropped from 99% to 96%. I was surprised to see the SOC drop so much considering that the only thing drawing a current overnight would have been the CO monitor. No lights, fan, heater, etc were running. Is there a chance that I have some "vampire" current being sucked out somewhere or does a 3% drop in SOC overnight seem reasonable?

[Vic Harder]

Important bits you may have already thought of:

 

A) when you plug in your NOCO, it also needs to go "through" the shunt so that the BMV can read the incoming charge

If you want to Synchronize to 100%, leave it in the sun, with the NOCO plugged in for a day... so it is for sure fully charged

C) You will want to "Calibrate" your BMV as well.. so pull the kill switch and the CO monitor fuse/connection so that NOTHING is drawing any current and use the calibrate function on your BMV.  Leave the CO disconnected and put the kill switch in the on position and the BMV on the current screen.  It should indicate no current flow.  If it does, pull fuses to figure out what circuit is still drawing power.  Don't forget to reconnect your CO monitor after all this testing

D) Deka's specs are here - https://www.eastpenn...meters-1913.pdf  stuff that matters to you: 

- Bulk/Absorb voltage = 14.1 - 14.4V

- Float voltage = 13.44 - 13.56V

- temp coef = -3mV

[ExplOregon]

No way I can think of everything so keep the important bits coming

 

Regarding:

A) Yes, the NOCO unit is hooked up to the BMV shut with all the other negative wires. Haven't had the chance to leave the solar and NOCO unit out all day, but plan to do that this weekend since I'll be home.

 

C) So I noticed some odd things when looking into this item. The primary thing to note is that even with the kill switch in the off position (no power), the BMV is registering an irregular, small draw of current. On the trend/graph function of the BMV, it shows current at 0 amps, but every 5-10s it spikes to -0.1 amps and then back to 0 amps. Some times there will be multiple spikes in a row. With the kill switch in the on position, the BMV registers a consistent draw of -0.2 amps with nothing "on" but the CO monitor. I then tried your trick of pulling fuses with the kill switch on. I pulled the CO monitor first and the current dropped from -0.2 to -0.1 amps. Next I pulled the fuses one at a time. Nothing happened until I pulled the fuse for the USB bank. After that, the current rested at 0 amps. Note that nothing was plugged into the USB or 12V outlet. Is it normal for the USB to be drawing a current when nothing is plugged in? I also haven't "calibrated" via the app yet? Maybe I need to do that?

 

C.2) This weekend after a 3hr drive when the alternator was charging the batteries back up (from 90% to 99%), I noticed that just after turning the truck off that the BMV was registering a draw of -2 amps or -27W (I can't remember the specific numbers so no idea if 2 amps correlates with 27 watts. I just remember that it registered around -27W). This was with the kill switch off and nothing running but the CO monitor. Over an hour later, the draw had dropped to -0.1 that I mentioned above. This also seemed odd to me. Why was the truck drawing current/watts after it was turned off? Is this just the two batteries equalizing or something?

 

D) Thanks for the specs!

[craig333]

The big red switch. Unlike most I don't run a battery separator. All done with the switch. Position one runs the camper  on the camper batteries. Position two the camper runs on the truck batteries. Position 3 the camper runs on both. Three  would allow the alternator to charge the camper batteries and or allow the solar the charge the truck batteries. I've never had a reason to run the camper on the truck batteries but before I put new batteries in the truck I did use 3 to charge (basically jump start) the truck batts. It normally stays in position one. Solar does the job and I've yet to need to add in the alternator. Running the camper on the truck batteries is basically a holdover from the early days when there was no camper battery. 

[Vic Harder]

No way I can think of everything so keep the important bits coming

 

Regarding:

A) Yes, the NOCO unit is hooked up to the BMV shut with all the other negative wires. Haven't had the chance to leave the solar and NOCO unit out all day, but plan to do that this weekend since I'll be home.

 

C) So I noticed some odd things when looking into this item. The primary thing to note is that even with the kill switch in the off position (no power), the BMV is registering an irregular, small draw of current. On the trend/graph function of the BMV, it shows current at 0 amps, but every 5-10s it spikes to -0.1 amps and then back to 0 amps. Some times there will be multiple spikes in a row. With the kill switch in the on position, the BMV registers a consistent draw of -0.2 amps with nothing "on" but the CO monitor. I then tried your trick of pulling fuses with the kill switch on. I pulled the CO monitor first and the current dropped from -0.2 to -0.1 amps. Next I pulled the fuses one at a time. Nothing happened until I pulled the fuse for the USB bank. After that, the current rested at 0 amps. Note that nothing was plugged into the USB or 12V outlet. Is it normal for the USB to be drawing a current when nothing is plugged in? I also haven't "calibrated" via the app yet? Maybe I need to do that?

 

C.2) This weekend after a 3hr drive when the alternator was charging the batteries back up (from 90% to 99%), I noticed that just after turning the truck off that the BMV was registering a draw of -2 amps or -27W (I can't remember the specific numbers so no idea if 2 amps correlates with 27 watts. I just remember that it registered around -27W). This was with the kill switch off and nothing running but the CO monitor. Over an hour later, the draw had dropped to -0.1 that I mentioned above. This also seemed odd to me. Why was the truck drawing current/watts after it was turned off? Is this just the two batteries equalizing or something?

 

D) Thanks for the specs!

 

c) If pulling the fuse for the USB panel changed the readings, then yes, the USB is doing something.  Calibrate with all fuses pulled, including the CO sensor.  And yes, you need to calibrate, although it seems likely that it already is calibrated.

 

c2) Seems like your house batteries were "charging" the truck batteries a little bit, or yes... "equalizing"

[Vic Harder]

The big red switch. Unlike most I don't run a battery separator. All done with the switch. Position one runs the camper  on the camper batteries. Position two the camper runs on the truck batteries. Position 3 the camper runs on both. Three  would allow the alternator to charge the camper batteries and or allow the solar the charge the truck batteries. I've never had a reason to run the camper on the truck batteries but before I put new batteries in the truck I did use 3 to charge (basically jump start) the truck batts. It normally stays in position one. Solar does the job and I've yet to need to add in the alternator. Running the camper on the truck batteries is basically a holdover from the early days when there was no camper battery. 

 

That works.  KISS.