Question to Battery Gurus... (1 Viewer)

[Sandroad]

I

This is really all anyone needs for extended off-grid travel.

So expo:
https://www.amazon.com/Renogy-Monoc...35652153&sr=8-17&keywords=100w+portable+solar

I use a Renogy 100w flexible panel for my camper when off the grid. Runing the power through a Morningstar MPPT charge controller to a couple of Duracell group 31 AGM batteries gives me all the electricity my camper with 2 people needs pretty much indefinitely. The RV industry has many solutions on many scales of many parameters for off grid power. For me choosing the best for a particular need often means using Occam’s Razor.

 

[indycole]

Can you expand on the redarc exchange? They market to just such solutions (or at least their proponents do), so I’m curious.

Redarc has a solution for many electrical situations but there are only so many things you can do to keep an AGM starting battery fully charged. I originally reached out to get their feedback on a cockamamie idea to place a solenoid-based switch between the alternator, the starting battery, and a BCDC. The idea was to 1.) directly connect the alternator to the battery upon startup, 2.) press a switch inside the cabin that switches the alternator to connect to a BCDC which then, 3.) charges the primary battery using the right charging profile. This was more of a theoretical investigation as that solution is a little hacky for my tastes. Either way, they did not recommend doing that.

They did recommend the following options:
* Swapping out my current AGM for an AGM that "does better" with the stock alternator's output (Northstar / X2 Power, Odyssey, and Optima don't seem to get a full charge... I don't know about Interstate?)
* Install roof-top solar panels that connect to the primary battery instead of the aux battery (not opposed to this but already have way too much weight on the roof... even if panels aren't that heavy)
* Charge the AGM battery at home (what I currently do)

Other options
* Be okay with never getting a full charge... the best the alternator will do is 80-90% for my Northstar / X2 Power
* Revert to a flooded battery (I actually considered this but one reason I went AGM is that I broke a flooded battery in my prior vehicle when traveling offroad)
* Trick the alternator using the HKB / Dirty Parts diode-infused fuse — this was my original plan but as mentioned in other posts I couldn't get that solution to work on the 2016
* Try out the hacky idea above (I wouldn't be surprised if the truck exhibits some strange behavior in the microseconds during the flipping of the switch)
* Swap the alternator and/or voltage regulator... not for me

 

[TeCKis300]

I use a Renogy 100w flexible panel for my camper when off the grid. Runing the power through a Morningstar MPPT charge controller to a couple of Duracell group 31 AGM batteries gives me all the electricity my camper with 2 people needs pretty much indefinitely. The RV industry has many solutions on many scales of many parameters for off grid power. For me choosing the best for a particular need often means using Occam’s Razor.

I agree with you and I think a 100W flexible panel is the most elegant solution here. Travel trailers/campers have been transitioning to this strategy.

It does depend how people want to use their systems. In general, working to increase power reserves gets to be too heavy and expensive, especially for a mobile vehicle. It’s better to attack the power generation angle, which potentially can give infinite reserves off grid.

Most overlanding type trips involve lots of vehicle on time. Batts literally don’t matter during this time as power is provided by the alternator – for winch, lights, electronics, etc. Batts come into use after setting up camp. There should be enough reserve to go through the night and some margin into another day perhaps. That doesn’t take huge batteries banks to accomplish. Like I said, with my camper with way more electrical loads than an overland vehicle, two group 27 (~160ah, 80 usable, will cover me almost 2 days). So these dual 31 AGM setups are waaaay overkill, nevermind the huge weight penalties.

A better setup would be a single large 31 (flooded for best compatibility), or two smaller 24 or 27s as redundancy (weight!). With handheld emergency jumper as backup. Supported with a 100W flexible panel perhaps deployed on the hood if one is camping during the day. Since it’s portable, if you’re under shade, you can reposition outside of the shade as necessary. With an easy to get to connector right at the base of the windshield. Easy, no brainer setup, no transfer switches, no wiring of independent circuits. Potentially infinite battery reserves.

 

[linuxgod]

* Install roof-top solar panels that connect to the primary battery instead of the aux battery (not opposed to this but already have way too much weight on the roof... even if panels aren't that heavy)

FYI not that you want to go this route, but the 100W flexible solar panels weigh about 2#, and could be taped down to the roof (or the top of a hard-top RTT) with some 3M VHB tape or Eternabond.

 

[TonyP]

A non-hardmouted panel might be ideal for vehicles like these. Re-positioning your vehicle throughout the day for optimal sun exposure might be a pain. Also, if you want to park under some shade, you'll have issues. Or if you don't have a RTT and want to put stuff on the roof. With a mobile panel, put it wherever, angle it however, fold it up and throw it in your rig when you're done. Potentially less damage too from branches or rocks or raining frogs or whatever.

 

[indycole]

FYI not that you want to go this route, but the 100W flexible solar panels weigh about 2#, and could be taped down to the roof (or the top of a hard-top RTT) with some 3M VHB tape or Eternabond.

You're right, I'd actually like to figure out a way to tape some think surface-mount panels to the top of the RTT in such a way that the panels won't overheat/lose efficiency. I'd use the roof-top panels to keep the starter AGM topped off.

That said, the roof-top panel would work relatively well while driving but who wants to park in direct sunlight when camping and move the vehicle around to get the incident sunlight... especially after leveling for the RTT? That's when you whip out a second solar panel in the form of a blanket or panel that you can move around and keep your house battery charged, as Mr. P said.

 

[Mineral]

Hey Guys,

By way of general followup, I picked up the X2 in 27F on a Friday. Was a simple plug and play. Ran a couple local errands and let her sit for over a day.

Today (Sunday), I drove out about 10 miles for a quick visit this afternoon. Ducked in where I had to go for 15 min, then went back home.

Before I left home, the battery registered 12.68v. When I returned, the battery registered 12.98v. This is on stock diode in an 11 LC200; voltage booster is still in transit from Oz.

Isn’t full charge for an AGM at 13.0v, per the attached?

The alternator was probably charging at the “cold” setting for most the short errands (higher voltage).

But, this leads me to think the stock diode might be doing the trick with keeping this X2 near top off.

Am I being lulled into a false sense of security thinking the voltage booster might not be needed? Will the charging profile change on a long trip and/or after eating into the X2’s capacity with a few nights of lights and tunes? Or maybe I just have a freak alternator / diode setup that is a little outside the typical bell curve in favor of AGMs?

Let the school bell ring; am ready to learn.

 

[Mineral]

Parenthetically, here is why I went X2 27F, if anyone is curious.

Both X2 27F and 31M were avail locally, whereas the Interetate 31P-AGM7 required up to 2-3 weeks wait. Odyssey’s are awesome, supposedly, but the dearth of dealer network killed that brand as an option for me.

Relative to the X2 31M, the 27F had 9/10 the amp hours at 5/6 the cost, and required no mods to fit in the primary tray.

The 27F also has a 5 year warranty whereas the 31M has a 4 year warranty. Fwiw, the guys at Batteriesplus claim they hardly ever see an X2 go belly up prior to the warranty window - even in the Phoenix heat. That helped the decision, too.

Not saying X2 27F is the best solution for everyone; it works for me and my use case living in Phx.

Happy battery hunting to all and finding what works best for you!

 

[RET2]

If you're not running a fridge or other appliances you most likely will be fine. BTW the stock setup is just a fuse not fuse diode combo. In addittion the voltages you measured will go down as the surface charge wears off to what is called a float voltage. All of the electronics have a small but steady parasitic draw. It maybe enlightening to install a dual voltage meter to monitor battery state?

 

[tbisaacs]

Parenthetically, here is why I went X2 27F, if anyone is curious.

Both X2 27F and 31M were avail locally, whereas the Interetate 31P-AGM7 required up to 2-3 weeks wait. Odyssey’s are awesome, supposedly, but the dearth of dealer network killed that brand as an option for me.

Relative to the X2 31M, the 27F had 9/10 the amp hours at 5/6 the cost, and required no mods to fit in the primary tray.

The 27F also has a 5 year warranty whereas the 31M has a 4 year warranty. Fwiw, the guys at Batteriesplus claim they hardly ever see an X2 go belly up prior to the warranty window - even in the Phoenix heat. That helped the decision, too.

Not saying X2 27F is the best solution for everyone; it works for me and my use case living in Phx.

Happy battery hunting to all and finding what works best for you!

Redarc has a solution for many electrical situations but there are only so many things you can do to keep an AGM starting battery fully charged. I originally reached out to get their feedback on a cockamamie idea to place a solenoid-based switch between the alternator, the starting battery, and a BCDC. The idea was to 1.) directly connect the alternator to the battery upon startup, 2.) press a switch inside the cabin that switches the alternator to connect to a BCDC which then, 3.) charges the primary battery using the right charging profile. This was more of a theoretical investigation as that solution is a little hacky for my tastes. Either way, they did not recommend doing that.

They did recommend the following options:
* Swapping out my current AGM for an AGM that "does better" with the stock alternator's output (Northstar / X2 Power, Odyssey, and Optima don't seem to get a full charge... I don't know about Interstate?)
* Install roof-top solar panels that connect to the primary battery instead of the aux battery (not opposed to this but already have way too much weight on the roof... even if panels aren't that heavy)
* Charge the AGM battery at home (what I currently do)

Other options
* Be okay with never getting a full charge... the best the alternator will do is 80-90% for my Northstar / X2 Power
* Revert to a flooded battery (I actually considered this but one reason I went AGM is that I broke a flooded battery in my prior vehicle when traveling offroad)
* Trick the alternator using the HKB / Dirty Parts diode-infused fuse — this was my original plan but as mentioned in other posts I couldn't get that solution to work on the 2016
* Try out the hacky idea above (I wouldn't be surprised if the truck exhibits some strange behavior in the microseconds during the flipping of the switch)
* Swap the alternator and/or voltage regulator... not for me

Also looking to be schooled. I have a single X2 27F. May go dual someday but not now. Would the redarc bcdc be effective maintaining a single agm primary battery? I was under the impression it was designed to keep a secondary charged up.

Have also considered your route-just get a Noco or Odyssey AGM charger and top the battery up fully once in a while.

 

[Mineral]

At the risk of inadvertently burrying tbisaacs question, please look above ^^^^^

BTW the stock setup is just a fuse not fuse diode combo.

Thx for that clarification. Appreciate the attention to detail.

In addittion the voltages you measured will go down as the surface charge wears off to what is called a float voltage. All of the electronics have a small but steady parasitic draw. It maybe enlightening to install a dual voltage meter to monitor battery state?

Good to know. Learned something new. Thx.

So, the instrument cluster has a battery gauge in the 2011. It’s analog, but the needle was fairly accurately hovering over the “13v” marker today. Am guessing you could approximate to the nearest half to maybe quarter fraction using the factory meter. Which could be a good enough ballpark to see how the battery fairs as the surface charge wears off. Perhaps when I triple lock, I’ll add a more granular voltage meter when also putting in the e-locker engagement mechanism.

 

[indycole]

Also looking to be schooled. I have a single X2 27F. May go dual someday but not now. Would the redarc bcdc be effective maintaining a single agm primary battery? I was under the impression it was designed to keep a secondary charged up.

Have also considered your route-just get a Noco or Odyssey AGM charger and top the battery up fully once in a while.

Are you monitoring the voltage on the 27F X2? I'm curious if it's staying completely charged as I could also consider going down in size the next time around. We've been on a bit of a road trip over the holiday and after 8 hours of driving it did look I got almost a full charge on the 31 X2.

Redarc did not recommend using a BCDC for a single primary AGM and I haven't seen evidence of one trying it. I was mainly interested in whether that would work, theoretically, but they could neither confirm nor deny. Hitting the battery with a charger every so often isn't too inconvenient.

 

[TonyP]

I think using the BCDC to charge just one battery would work. But charging it, manually to top it off, before a camping trip would be quicker, easier and cheaper.

 

[tbisaacs]

Are you monitoring the voltage on the 27F X2? I'm curious if it's staying completely charged as I could also consider going down in size the next time around. We've been on a bit of a road trip over the holiday and after 8 hours of driving it did look I got almost a full charge on the 31 X2.

Redarc did not recommend using a BCDC for a single primary AGM and I haven't seen evidence of one trying it. I was mainly interested in whether that would work, theoretically, but they could neither confirm nor deny. Hitting the battery with a charger every so often isn't too inconvenient.

I’m at 12.81v after sitting over night.

 

[Mineral]

12.81 is about a 95% charge - at least according to the chart above. That seems to be pretty good.

Some followup questions:

• How long have you had the 27F? Curious if you already wore through the surface charge to float voltage.
• Do you have a voltage booster installed on your 08 LX?
• Are you running any appliances?

Thx!

 

[tbisaacs]

12.81 is about a 95% charge - at least according to the chart above. That seems to be pretty good.

Some followup questions:

• How long have you had the 27F? Curious if you already wore through the surface charge to float voltage.
• Do you have a voltage booster installed on your 08 LX?
• Are you running any appliances?

Thx!

I bought the X2 back in June and immediately put it to use powering my ARB fridge so I definitely have burned though surface charge. I also use a Renogy voyager solar controller to plug in a 100w panel at camp. I also have a new alternator and dirty parts diode (more on that here).

 

[linuxgod]

Isn’t full charge for an AGM at 13.0v, per the attached?

It depends on the battery. The WindyNation 100Ah AGMs have a full charge at 12.84V and are fully discarged at 11.64V. Email the manufacturer and ask, don't just assume.

 

[Mineral]

Here is the official reply from NorthStar's Director of National Accounts, Transportation Products:

Thank you for reaching out to NorthStar Battery.

A fully charged 27F battery will range between 12.7 – 13.0 volts.
​

[edit 9/11/18]

By way of follow-up conversation, the below was provided in supplement:

The chart is below. I will caution you that this charge (SoC in general) is based on Open Circuit Voltage (OCV), which means when the battery is not connected to anything. Once the battery is connected to a circuit, you would then be looking at Closed Circuit Voltage (CCV) and that chart is based upon amp load of the circuit and therefore there is no standard chart.

They did recommend the following options:
...
* Charge the AGM battery at home (what I currently do)

After sharing the thread with the Northstar rep, he asked me to share the following on Indycole's above post:

Thanks for sharing the link. Looks like a fun forum!

I was reading post #82 from indycole and would be curious to know what type/size of external charger he is using. I recommend using a 15 – 25 amp smart charger to thoroughly charge pure lead batteries.

I would recommend the Dual Pro PS1 or NOCO’s G15000

Both manufacturers offer larger amperage output options, but for single battery applications (including group 31’s). 15 amps is sufficient.

Use the dongle disconnect and leave the battery plugged in when the vehicle is not in use (assuming it is not a daily driver). This will ensure the battery is at full capacity when you hit the trail.

Feel free to reach out with technical questions anytime…I’ll do my best to assist.
​

Great customer service over at NorthStar: friendly, informative, and prompt!

​

 

[Mineral]

Also, fwiw, the transit time for the HKB diode is currently slower than expected.

Great customer service, tho; they responded to my inquiry right away. Here’s their response:

Usually takes 1 week or so arrive in US, then 1-3 for USPS to actually deliver it for some reason.
​

[Edit 9/15/18]

HKB diode arrived this week, taking about 2 weeks between order placement and receipt.

Install today was straight-forward and took all of 5 minutes.

Before install, when vehicle was pretty much cold, wife revved to 1500 and the meter piqued at 13.77 volts.

After install, still cold, she revved back to 1500, per instructions, and the meter piqued at 14.23.

That's a 0.46v jump - which is shy of the advertised 0.5 - 0.6v gain. But, the instructions say that the voltage should rise after revving the engine slowly to 1500 and also waiting a bit. And, perhaps, my simple Autozone meter has a margin of error, too.

Both the stock reading and the modified reading fell within the expected ranges specified by HKB, so called it good.

 

[PhillipPinot]

Hi, what was the consensus? Could anything else fit in the Slee tray and connections? I'm having a tough time locating a 31P-AGM7 but the 31M-AGM7 and 31-AGM7 were in stock.

Edit: wow, so it seems like the AGM batteries really aren’t good to have on the 200? I think I’m better off returning the Slee battery tray and just getting a “normal” battery.