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How fast your battery will charge is determined by two key factors – your battery’s Amp per Hour (AH) rating and the charger’s rate of charge. Your 100 AH battery at 10 amps speed will be charged in about 10 hours and at 5 amps in about 20 hours or more.
Battery charging is a long process and is usually done in stages (with a good quality charger). Lithium batteries are known for their high recharging speeds and capacity to consume practically all of the energy stored in them before needing to be recharged. They also cost more than other types of batteries.
Lead-acid deep cycle batteries are the most widely available and least priced on the market. They do, however, have some disadvantages, such as the necessity for regular maintenance and the slow charging speed.
The capacity of deep cycle batteries is measured in Ah (Amp Hours). The most popular deep cycle battery for RV is Group 24 with a capacity of 70Ah-100Ah.
The charging process increases the heat inside the battery and usually, the slower it’s being charged, the better. If you charge a GEL or AGM deep-cycle battery super-fast, you may lower its lifespan.
Multi-stage battery charger
Slow, multi-stage charging is the best option because it has no negative impact on the battery’s cells or plates. Here is my pick for the best AGM/GEL battery charger (paid link) and yes, you can click on the picture:
You can charge a lithium battery using a lead-acid charger if you want, but you must not use a lead-acid charger with an automated “equalization mode” that cannot be switched off permanently. The charger from NOCO Genius (paid link), on the picture below, can charge them all:
And this is a good, detailed explanation of what size of charger you need for fast charging your battery:
Even though you may be pressed for time, make sure your RV battery is fully charged before setting off on a trip. Your battery will charge faster if there is no load connected to it while charging.
Converter-charger (at the RV park)
The ability to have lights, appliances, and devices is one of the key advantages of camping in an RV over camping in a tent. If you own an RV, the knowledge of how to use your electrical system in your vehicle is critical.
Your battery is the heart of the electrical supply system, around which the entire system revolves. Lead-acid, AGM (Absorbed Glass Mat), and lithium are the three most common varieties of RV batteries.
12-volt batteries are usually used in RVs since some RV appliances and lights run on 12 volts. Deep cycle batteries are usually preferred by RVers because you can discharge them deeper before recharging.
Each of these types has its own set of benefits and drawbacks, such as charging time, maintenance requirements, and the amount of stored energy that can be used before recharging is required.
When you plug into a power pole at a campground, the AC current from the power pole charges your home batteries through your convertor. It can take a long time to recharge your batteries this way, especially if your batteries are lead-acid.
However, while they’re being charged, you may use the DC power that comes straight from the pole to power your RV. Many campers boondock for many days, exhausting their batteries, then stay a night at an RV park to hook in and recharge their batteries before going boondocking again.
Boondocking (which is camping without access to utilities like electricity and water), is one of the most prevalent uses for an RV battery. The fastest way to charge your RV batteries to utilize when boondocking is to connect them to a power outlet at your RV park with enough power amps.
Whether you are plugged into the shore power or are using a generator, the converter in RV is responsible for charging your batteries. This is the most common method of battery charging while away from home.
Depending on how low your battery is, this could still take 3 to 4 hours. If your battery is completely dead, expect to wait at least 10 hours for it to be fully charged.
If you are in an RV park already and your battery is not completely depleted, just plug it in and let it charge by itself. You will be able to use appliances alongside charging and enjoy a wonderful camping experience.
Alternator (on the road)
An RV battery is a 12-volt power source that may provide all of the energy your RV requires. If you’re driving a motorhome, the alternator in your engine can charge your house batteries as you travel.
As you go from one boondocking location to the next, using the vehicle’s alternator is a terrific method to keep the batteries charged. When you start your RV engine, unlike the chassis battery, your house batteries will NOT start charging automatically.
You need a special setup to do that. DC-DC chargers are specifically designed to charge your service battery with an alternator. Here is a good quality charger from Victron (paid link):
This excellent charger in the picture above also comes with a Bluetooth smart system. It can be turned ON / OFF remotely, and even detects if your engine is running! Can be used with either lead-acid or lithium-ion.
Here is a good wiring explanation:
To charge your battery while driving your RV will need the following accessories:
- Voltage-Controlled Relay
- Anderson plugs
- High amperage cable
Connect the start and house batteries to the VCR first. Stable connections and decreased voltage loss can be achieved by using high-quality cables and plugs.
It will help prevent the connection from being lost when traveling over uneven terrain. A 50 amp auto-reset circuit breaker connected to the positive side of the battery will also reduce the chance of overheating.
Remember to keep an eye on the battery when driving and not overcharge it. Using a professional DC to DC adaptive 3-stage charger (paid link) can help with that.
Other charging methods
If your RV is equipped with photovoltaic panels (that collect solar energy and store it in the coach batteries), all you need is a good quality charge controller and you are good to go!
To avoid damaging your batteries, you’ll need a solar charger controller. It adjusts the current and voltage flowing from the solar panel to prevent your battery from being overcharged.
Charge controllers from Victron (paid link) seem to be very popular among RVers:
Charge your batteries with a generator wherever you’re camping, but don’t forget that these “noisemakers” will keep your neighbors up at night and you don’t want to do that! Unless you like to drive people crazy, of course…
A generator will charge your batteries in the same way that a power pole would in an RV park:
Your generator provides 120 volts AC to the converter in your RV, which then charges your batteries.
Some people choose to charge their RV’s batteries using their generators, especially if they need a charge in an emergency. Although generators are an excellent alternative for emergencies, they were not designed to be used for continuous charging.
A standard generator produces only 12 volts, however, charging a battery requires roughly 13.6 volts. You might be able to charge a partially depleted battery in 5 to 6 hours if you keep going at this rate.
If you want a good generator that can be used to charge in an emergency, make sure it’s heavy-duty and has at least 4,000 watts of capacity. You can check out some generators here and filter them out by your needs.
This guy thinks that charging your battery with a generator is the fastest way to do it:
A typical RV generator is not usually very powerful and will charge your batteries in a reasonable amount of time (in between 10 and 24 hours). However, if your generator is 4,000 watts or above, it will charge your RV batteries considerably faster!
You can (and you should) install a battery monitor in your RV to know exactly how much energy your batteries have and how much is being utilized. Installation might range from just attaching one model to your battery poles to placing a gauge inside your RV.
These monitors should give you an idea of the state and capacity of the batteries. Some even allow information to be accessed via a Bluetooth phone app.
They are available in a variety of shapes and sizes, with the most popular being a Victron model (paid link). Conveniently available from Amazon:
Higher-end monitors will have gauges and meters that display how much power is used and how much energy is stored during charging.
You can prevent overcharging and temperature extremes by using a battery controller! It will keep your batteries from becoming overcharged. When the battery is full, the controller will limit or halt charging.
The battery disconnect switch should be turned off while the RV battery is not in use. It’s a good idea to unplug the batteries or use a trickle charger when storing your trailer or coach.
Tips for charging your battery fast!
Because RV batteries are needed when there are no external power sources available, keeping your batteries charged is critical. Make sure to check your battery at least 48 hours before your travel so you have enough time to charge it and don’t have to worry about overcharging it.
A basic battery charger can charge your battery in 20 to 48 hours, depending on the amps and chosen charge speed. Batteries their own can only do so much, but they’ll keep you going until you can find a more powerful power source.
You should attempt to maintain your batteries charged at all times to prevent them from dying completely. Dead batteries take far longer to recharge than partially charged batteries.
The majority of conventional RV batteries will lose 4% of their charge each week. To keep your batteries from entirely going out, you may want to invest in a compact battery charger (between 2 and 5 amps) that can help keep them charged while not in use.
If you are unsure about the state of your batteries, then have them tested by a specialist. You can take your RV batteries to almost any repair shop or dealer and have them looked at.
You can keep your battery on a trickle charger (2 to 5 amp), to avoid total battery drains in the future and that is a real time-savior!
Make sure the plates of the battery are submerged in liquid as well. If they aren’t, unscrew the caps and fill the filler tube with distilled water to the bottom. After that, you’ll want to charge the battery right away.
** Warning! The battery contains powerful acid, therefore wear gloves and safety glasses to protect yourself, when filling the battery with water. If you don’t feel comfortable doing it yourself, you can have it done by a professional at a repair shop.
There are many methods of how to charge your batteries and they will all work with a proper setup. Quick (or fast) charging basically comes down to how powerful your charger is and how fast are you willing to charge it!
Charging too fast is generally NOT recommended for any type of battery, but, if you really need to, deep cycle lithium-ion batteries are your best bet!
This article is for informational purposes ONLY and is NOT a replacement for professional advice!