Charging Deep Cycle Batteries in RV

[winnieslave]

What are the best ways to keep deep cycle batteries charged off grid without installing expensive solar panels?

 

[DavidEM]

A generator built in or portable driving the converter aka battery charger.

David

 

[Oldchinahand]

Yep

Fair Winds and Following Seas

 

[powercat_ras]

Install a battery monitoring system (BMS) that uses a shunt to give precise Amps In / Amps Out and % battery charge information. Generator to power the 120 VAC Converter / Charger (CC). The BMS gives you the information you need to see when the CC drops out of bulk charge mode into topping charge and/or float charge mode. Once the battery charge reaches 80% the CC will drop out of bulk charge mode and it takes many hours for the CC to go from 80 % to 100 % , and you may choose to shut off the generator and safe the fuel and lose the noise once your batteries recharge to 80%.

 

[Calson]

Adding solar panels or buying one of the fold out kits with a charge controller is the most economical solution. A generator will cost $1100 and then you need an adapter cable and carry around a gas can in the RV. With standard batteries the time to take them from 50% to 100% SOC will be considerable, as in hours. Solar panels provide slow charging which is more in line with the charge level that lead acid batteries can accept.

I went for years with two 100AH lead acide batteries and two 100W solar panels with no issues. I had a 3-way fridge so less demand than with the DC only ones. I had no need to haul around a generator or carry cans of gasoline.

 

[woodsyowl]

What are the best ways to keep deep cycle batteries charged off grid without installing expensive solar panels?

I agree with Elkman. A portable fold up solar panel with builtin controller will do the job much more cheaply than a generator. Solar runs for free and very little maintenance. Plus, no noise, no fumes, no gas can. Will also run the lights in your unit and probably your TV too. I run my DISH satellite and TV plus lights and water pump. Charges batteries during the day. Like magic.

 

[BCam]

DIY solar isn't all that expensive and installation is fairly straightforward for those with average DIY skills. Here's a Renogy 200 Watt, 2-panel kit with a 40W MPPT controller for under $400:

https://www.amazon.com/Renogy-Monoc...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Renogy has a less expensive kit with a lower model 30A PWM controller for under $300:

https://www.amazon.com/Renogy-Monoc...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Additional 100W panels can be added for approximately $100 each to the maximum capacity of the controller. You can also save money by assembling your own "kit", but I'm not sure the savings will be too significant.

Although portable panels can be more efficient since they can be positioned for optimum efficiency, with installed panels, there's nothing to set up and they're operational while in outside storage, thereby keeping your batteries charged. I installed an Amp-L-Start between my house and chassis batteries so, once the house batteries are charged, the chassis batteries will be charged as well.

There's also the potential theft issue with portable panels.

The one advantage of a generator is the ability to run things like your microwave. Although it's possible with an inverter, the drain on your batteries is significant, not to mention the cost of an adequate converter.

The cost of relatively quiet generators has decreased over the years to under $500 for some models. When I bought my Honda 2000i it was the only good choice at about $1,000 (I still think Hondas are the best). Even so, I considered it too noisy to use it for long term battery charging and its primary use was for running the microwave while camping without power. Note that generators can create more noise for your neighbors than for you, depending on how the exhaust is oriented. My MH has a built in generator and I feel the same about it, we like quiet when we camp.

 

[golden13]

This is less than $100

What are the best ways to keep deep cycle batteries charged off grid without installing expensive solar panels?

https://smile.amazon.com/gp/product/B07BMQRNXZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
50W INCLUDING the solar "brain." More than adequate to keep 100-200 Ah batteries topped off. It's flexible and waterproof!

 

[BCam]

https://smile.amazon.com/gp/product/B07BMQRNXZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
50W INCLUDING the solar "brain." More than adequate to keep 100-200 Ah batteries topped off. It's flexible and waterproof!

50W will keep the batteries "topped off" while in storage but would be woefully inadequate while camping "off the grid". The OP wasn't clear as to the situation being addressed. If power is being used to any degree, based on my personal experience, 200W of solar should be adequate if one is careful as to power use.

 

[HappiHenri]

Solar panels are not expensive any more. But a good solar system requires really good batteries - especially Lithium - if you want to get the job done right.

On my Class A I have 600 watts of solar panels and 400Ah of LiFePO4 batteries. The system works great and provides plenty of juice to power everything - microwave, TVs, lights, etc. - BUT - only when the sun shines.

Learned years ago that as much as I love having this solar setup that the sun does not always shine and/or I end up parking in the shade of a lot of trees. When that happens I have no choice but to run my generator to keep the batteries charged.

So the answer to your question is - make sure you have the generator 1st. Then, should your dry camping needs require more off-grid power you can always add solar and better batteries. But unless you spend most of your time in RV parks plugged into shore power you will need a generator - no way around that.

 

[Calson]

Last month I bought a Grape 190W panel for $218 and a Renogy 100W panel for $103. Home Depot currently sells a Renogy starter kit with one 100W panel and a charge controller for $195. I paid a local RV tech $420 to install them both on my Navion and to move a badly placed Zamp panel installed by some fool at Winnebago. Hardly what I would consider expensive.