Renogy Batteries

[crater]

Originally Posted by Bill in Redlands

I recently installed 400 watts of solar on the roof and believe it will go a long way toward keeping them charged. Planning a road trip to see if I am right.

You'll get on average 30 amp hours of battery charge per 100w (maybe more maybe less kind of thing depending on sunlight and how it's hitting your panels).



I recently installed 1 of them in our Delano and it came with 100w of solar on the roof(and the controller luckily supported lithium already) and we go out for our first boondock this weekend. I did however leave the inverter and radio on all night the day i installed to try and kill the battery a bit and overnight only ended up using 19 amp hours. Then solar charged that 19 amp hours before 1pm the next day. I think you'll be pretty happy with your setup and will recharge in no time.



I might add a 2nd battery, this weekend is going to be basically a shake down test to see what we're really using and if its necessary to give battleborn another 900 bucks :-D



I also replaced the converter with a Progressive Dynamics one that tops of lithium properly.



Also, I grew up in Crestline and lived in Banning for a bit and worked in Redlands (as ESRI). Moved to LA for work and then eventually to Idaho now. The only thing I miss is Baker's Drive thru.

[Chance]

A lot depends on expectations; and on how RV will be used.

19 Amp-hours is only around 230 Watt-hours, so if powering a full-size RV microwave, for example, you’d go through that 19 Ah in about 8 minutes.

For campers who don’t use much power, it’s a great way to go in order to power LED lights, fans, water pump, TVs, etc. These are all low power users, although they can add up quickly. However, if wanting to power microwave, coffee maker, etc. even a few minutes a day, it’s best to consider all energy needs carefully.



On this subject, it’s interesting that with the optional 380 Watts of solar on 2021 Coachmen Cross Trek Class B+ one could get around 100 Ah of solar charge daily. Since there isn’t a generator, that should keep from having to run engine to charge batteries most days as long as A/C isn’t used while boondocking. Anyway, just shows that as long as there is enough battery capacity to accept solar production, it will reduce generator time considerably (provided air conditioning isn’t needed). Other than powering A/C, there’s much less need for generators any longer.

[Bob Denman]

Chance,
Question: If (A very big "If"...) you have a 350 watt system on your roof, and it's getting 8 hours of Sun daily...
Assuming at least average efficiency: how can you figure the Amp-Hours that'll it'll put back into your batteries?

[Chance]

Originally Posted by Bob Denman

Chance,
Question: If (A very big "If"...) you have a 350 watt system on your roof, and it's getting 8 hours of Sun daily...
Assuming at least average efficiency: how can you figure the Amp-Hours that'll it'll put back into your batteries?

A very rough average for typical solar production is 3 times the panel’s rating. Therefore, 350 Watts of nominal capacity should yield around 1,000 Watt-hours of energy. If you have a 12-Volt system (and most RVs do), then it’s about 85 Amp-hours into batteries.

Again, very average because in winter, or rainy day, etc., you could get much less, and if in summer in the desert, you could easily exceed 100 Ah on a good day.

One disadvantage of solar for my type of use is that I can’t count on it to meet my needs all the time, and if I need a backup charging system anyway, then why bother? I have mixed feelings about solar in my future because the more energy I need, the less appealing it becomes.

[Bob Denman]

Thanks for the info!
And I fully understand that "my mileage may vary".

I saw that Renogy was offering a 350 watt flexible solar panel kit that comes with an mppt controller.

[Chance]

Yes, and another major factor is that the smaller the RV, the less free space there is on roof, so it limits amount of panel capacity. Yet, power needs may not be proportionally different between a van and large Class A.

[crater]

Originally Posted by Chance

One disadvantage of solar for my type of use is that I can’t count on it to meet my needs all the time, and if I need a backup charging system anyway, then why bother? I have mixed feelings about solar in my future because the more energy I need, the less appealing it becomes.

Yeah, that's totally key here. Like you mentioned before if you're trying to run A/C and Microwaves and all that you can burn it down quickly. If you're like my wife and myself where we only sometimes boondock and our cooking is done all propane and usually only out there for maybe 3 day weekends. Then a single 100ah lithium and 100-200w solar may be totally fine.

[Chance]

For the first 20 or so years of RVing, we drove from campground to campground with full hookups, so solar would have been 100% useless. And since we didn’t rely on inverters, one battery was plenty to power the water pump and miscellaneous 12V electrical stuff during day while driving. For that type of travel, solar, lithium, etc. would have been pointless. Granted, we spent a lot on campgrounds.

Our generator didn’t get much use either because during the day we used it a few times to power microwave or leave dogs in motorhome with air conditioning.

Today, I would prefer trading generator for enough battery to run microwave or make coffee from an inverter, and also power A/C for a couple of hours. That’s as long as I would leave dogs unattended unless at a campground with shore power.

Needs are personal, plus they change over time. We boondock more now so our next camper needs to have different capabilities.

[The_Breeze]

Originally Posted by Chance

cut...

Needs are personal, plus they change over time. We boondock more now so our next camper needs to have different capabilities.

I'd question dumping the generator. An onboard, maybe, but not entirely. Maybe you stick with an onboard and then use that space for batteries sometime in the future? I don't know...

In the mean time, you may need a way to charge your batteries if you boondock a while. I just got away really cheap on a wet set of 4 and I'm ecstatic with the result. I don't need to run my generator when I do but I do it because I'm still learning. The lowest I've taken them is 12.22. They are deep cycle and feel I have some extra margin for error there. but don't want to take advantage of it. Just something else to ponder - like your head isn't full enough already. I ran the gen for 50m today, let them rest for 5m and they came in at 13.04.

(re: https://www.thorforums.com/forums/f1...tml#post239015)

[Bill in Redlands]

Originally Posted by crater

I also replaced the converter with a Progressive Dynamics one that tops of lithium properly.

Also, I grew up in Crestline and lived in Banning for a bit and worked in Redlands (as ESRI). Moved to LA for work and then eventually to Idaho now. The only thing I miss is Baker's Drive thru.

You got me cruising the web looking at converters that top the lithium batteries correctly. The Progressive Dynamics would work but does not fit in the space where my current converter is. I am looking for alternatives, either
a smaller converter or alternative space near the power distribution/fuse/breaker cabinet. On the Axis 24.2, that is a confined space below the fridge.

I ended up in Redlands chasing a job and raised my kids here. We like the ability to go to beach, desert or mountains on a whim. Maybe I'll drive through Bakers tomorrow - haven't had a shake in months.

[Chance]

Originally Posted by The_Breeze

I'd question dumping the generator. An onboard, maybe, but not entirely. Maybe you stick with an onboard and then use that space for batteries sometime in the future? I don't know...

In the mean time, you may need a way to charge your batteries if you boondock a while. ......cut.....

“Dumping the generator” has been discussed extensively on various threads dedicated to that specific subject.

With present-day technology, the main (practically only) reason most motorhomes need to haul around a generator is to power air conditioning for extended periods. This trend started with Do-It-Yourself van campers and spread to a few major manufacturers now offering compact motorhomes without generators.

While it’s possible to modify motorhomes extensively, it’s usually more cost effective to design and build them the way you want from onset. Doing major upgrades like replacing a generator with alternate forms of power would be too expensive for what you’d get. In my opinion I’d build motorhome initially without a generator, or else build it with a generator and keep it.

Between engine alternator(s), solar, and shore power, it’s possible to charge batteries without a generator, so air conditioning remains the major obstacle to eliminating generators. Unless of course you spend tons of money on a high-capacity lithium battery system like the EcoTrek, Volta, Xantrex, or the Thor system for vans (which I haven’t seen details on yet). Technically it can already be done, just takes money.

[Bob Denman]

Yes...
The issue of money!

https://www.thorforums.com/forums/at...1&d=1592581579

[Chance]

The only exception I’m aware of to spending lots of money on a high-capacity lithium-battery electrical system in order to eliminate the generator is the Coachmen Cross Trek line of motorhomes.

They seem to apply the cost of the typical Onan built-in generator towards a Xantrex 3,000-Watt inverter and much larger AGM battery. For 2021 they appear to have added extra battery- and solar-capacity options while keeping cost competitive.

That seems like a great and affordable middle ground for those who drive often, or camp in mild weather, and or mostly overnight in campgrounds with shore power. No doubt some RV owners use their generators a lot of hours, but many hardly use them much at all.

[Bob Denman]

That's why I keep looking at AGM batteries and solar power...

... and a bigger inverter...

...and re-wiring the rig to take advantage of the newfound power!

It never stops!

[Long & Winding road]

Originally Posted by Bob Denman

That's why I keep looking at AGM batteries and solar power...

... and a bigger inverter...

...and re-wiring the rig to take advantage of the newfound power!

It never stops!

Yep, never stops.

Bob, were you looking at 2 batteries for your setup? Like 200 - 250 amp Hr total (with 100 - 125 useable with AGM setup)?

You could get by with just 200 watt solar setup (maybe 300 to help on cloudy days). I just tought I would mention that since you were looking at a "350 watt" solar system.

[Long & Winding road]

Originally Posted by Bill in Redlands

You got me cruising the web looking at converters that top the lithium batteries correctly. The Progressive Dynamics would work but does not fit in the space where my current converter is. I am looking for alternatives, either
a smaller converter or alternative space near the power distribution/fuse/breaker cabinet. On the Axis 24.2, that is a confined space below the fridge.

I installed a progresive Dynamic in my Axis (My converter is Not for "Lithium" but you can us boost and make it work fine if one wanted to).

It fits just fine in my Axis (Mine is under the bed but still fits inside the OEM plastic "all in one" fuse box / converter box. So I'm bet the PD Litium version will fit yours just fine unless PD says it wont.

Sure its slightly larger than OEM....Larger fans + larger heat sinks but it fits perfectly in the OEM spot and works like a champ.

Just thought I would mention that.

[Long & Winding road]

Originally Posted by Chance

For the first 20 or so years of RVing, we drove from campground to campground with full hookups, so solar would have been 100% useless. And since we didn’t rely on inverters, one battery was plenty to power the water pump and miscellaneous 12V electrical stuff during day while driving. For that type of travel, solar, lithium, etc. would have been pointless. Granted, we spent a lot on campgrounds.
.

I agree..... most of us dont "need solar".... We just "Want it".

I have NOT installed solar ... yet... but it still on my short list. We do a lot of day trips. Might stay parked 6 + hours at a trail head (Mtn biking) or local lake front in off season .... Plus we will work several hours a day on the road while traveling. So I find solar would help sometime so I would not have to use the Genny as much or at all (if not too hot outside).

Plus my Frig. is setup on my inverter now so its nice to run it on 12 v instead of propane while on the road. So if the engine is not running the frig will pull my 2 agm batteries down pretty quickly when stopped. Sometimes I forget to turn the propane back on and turn the inverter off etc.

[Chance]

Originally Posted by Long & Winding road

I agree..... most of us dont "need solar".... We just "Want it".

I have NOT installed solar ... yet... but it still on my short list. We do a lot of day trips. Might stay parked 6 + hours at a trail head (Mtn biking) or local lake front in off season .... Plus we will work several hours a day on the road while traveling. So I find solar would help sometime so I would not have to use the Genny as much or at all (if not too hot outside).

Plus my Frig. is setup on my inverter now so its nice to run it on 12 v instead of propane while on the road. So if the engine is not running the frig will pull my 2 agm batteries down pretty quickly when stopped. Sometimes I forget to turn the propane back on and turn the inverter off etc.

I don’t want solar or “anything” unless it serves a real purpose or meets a need. I’m a believer in less-is-more as long as my needs are met. As a great man said, make it as simple as possible and no simpler.

If I stop to ride for a few hours, my batteries won’t go dead without solar during that short a period, and will recharge while I drive afterwards or at campground with hookups. Solar just adds more stuff on roof that I could do without. If I needed more juice, I’d add an extra battery before I’d add solar. Solar is great for boondocking multiple days in a row without driving, but we’ve never done that or have plans to do so. If some day that changes, I’d consider solar then.

Regarding your fridge, I certainly hope my next motorhome will have a 12V (or 48V) modern compressor fridge. I do not want another propane absorption fridge. I know for those boondocking for days at a time propane fridge makes sense, but that’s not us. For our type of travel/touring and camping, electric compressor fridge makes much more sense to me. I do want an efficient one though, not something designed for a house.

Also keep in mind that as alternators and batteries become more and more powerful, it makes solar less of a need for those that drive daily (unless they are in campground on shore power, in which case they don’t need solar anyway). Some high-capacity alternators can produce much more energy in an hour of driving than most solar systems in a 24-hour period. Granted, batteries must be able to accept fast charge rate, and that’s not always the case.

As usual, Devil's in the details.

[Bob Denman]

Originally Posted by Long & Winding road

Yep, never stops.

Bob, were you looking at 2 batteries for your setup? Like 200 - 250 amp Hr total (with 100 - 125 useable with AGM setup)?

You could get by with just 200 watt solar setup (maybe 300 to help on cloudy days). I just tought I would mention that since you were looking at a "350 watt" solar system.

The system I'm looking at comes with a pair of 175 watt flexible panels. I'd rather have more capacity than is necessary... With room to expand to 525 watts in the future.

[The_Breeze]

Originally Posted by Chance

cut...

Technically it can already be done, just takes money.

Isn't that almost always the final hurdle? I'm in SD. Was hoping to beat the heat and not run the A/C. Guess what?