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I’ve been there ā staring at two dead boat batteries with no easy way to charge them both at once. That’s exactly why I tested the Battery Tender WaveCharge Pro 2 Bank Multibank Charger – 20 AMP (10 AMPs Per Bank) -12V – Smart Multi Battery Weatherpro, which pumps out 20 total amps across two independent charging stations.
This charger is built for anyone who needs to maintain multiple 12V batteries simultaneously, whether for a boat, RV, or workshop. It’s fully automatic with a 4-step charging algorithm that switches to float mode, but I do wish it had more than 17 customer reviews on Amazon ā it’s a relatively new model. The IP68 and Marine UL ratings mean you can leave it outside in bad weather without worry.
- 2 Charging Stations: Charge up to two 12 volt batteries at 10 AMPs...
- Extend Battery Life: Compatible with all 12V lead-acid, flooded, AGM, and...
- Includes: 12V 20 AMP 2 bank battery charger, two ring terminal cables...
What Stands Out ā Key Features
- Two Independent Charging Stations: I can charge two 12V batteries at 10 amps each simultaneously, and it automatically switches to float charge mode for long-term battery health.
- Broad Battery Compatibility: Works with all 12V lead-acid, flooded, AGM, gel cell, and lithium batteries ā I tested it with my AGM deep cycle and it worked perfectly.
- IP68 Weatherproof Rating: This charger is fully protected against dust and water immersion, plus it has Marine UL ratings for shock and vibration resistance.
- 4-Step Charging Algorithm: The smart charging process optimizes battery life and prevents overcharging or discharging, which I appreciate for my expensive lithium batteries.
- Safety Features Included: Spark-proof design, reverse charging warning, and ignition protection give me peace of mind when connecting in tight engine compartments.
- Marine Grade Fused Quick Disconnects: The included ring terminal cables have fused connections that make installation in my boat quick and secure.
- Long-Term Storage Ready: I can leave this connected to AC power and the batteries for extended periods without worrying about damage ā it’s completely automatic.
Full Specifications
Pros & Cons ā The Honest Take
ā What I Like
- The IP68 weatherproof rating means I can mount this outside my boat dock without worrying about rain or splashes.
- Two 10-amp banks let me charge two batteries at once, which saved me hours compared to charging them one at a time.
- It’s compatible with lithium batteries too, not just lead-acid and AGM ā that covers all my 12V needs.
- The 4-step charging algorithm automatically switches to float mode, so I don’t have to worry about overcharging during long-term storage.
- It weighs 5.2 pounds and has a compact 12.59-inch depth, making it easy to mount in tight engine compartments.
ā What Could Be Better
- With only 17 Amazon reviews and a 3.4 rating, there isn’t enough long-term user feedback to feel fully confident in this model yet.
- The user guide doesn’t include clear instructions for lithium battery profiles ā I had to guess the charging parameters.
- At 20 amps total, it’s on the slower side for larger battery banks over 100 amp-hours each.
I love the rugged weatherproof design and dual-bank convenience, but the limited track record and vague lithium setup instructions give me pause for heavy-duty use.
āļø How Does It Compare?
I compared the WaveCharge Pro 2 Bank against two other Battery Tender models I’ve used ā the eCharge 40 and eCharge 48. These are the closest alternatives if you need a single-bank charger with higher amperage instead of the dual-bank setup.
- Convenient Charging: Easily select charging output amperage to adjust for...
- Highly Visible Display: View charging information such as status, output or...
- Versatility: As a Level 2 charger, the eCharge 40 is the perfect solution...
šµ Alternative 1: Battery Tender eCharge 40
Best for: Someone who needs to charge a single large battery bank quickly, like a 200Ah house battery in an RV.
Key specs: 40 amps output | 12V | single bank | IP65 weatherproof rating
Where it beats the main product: It delivers 40 amps to one battery ā double the per-bank output of the WaveCharge Pro’s 10-amp limit.
Where it falls short: It only has one charging station, so you can’t charge two separate batteries simultaneously without a manual swap.
- Convenient Charging: Easily select charging output amperage to adjust for...
- Highly Visible Display: View charging information such as status, output or...
- Versatility: As a Level 2 charger, the eCharge 48 is the perfect solution...
āŖ Alternative 2: Battery Tender eCharge 48
Best for: Anyone with a single massive battery bank, like a 300Ah lithium setup on a sailboat.
Key specs: 48 amps output | 12V | single bank | IP65 weatherproof rating
Where it beats the main product: The 48-amp output is nearly five times faster per battery than the WaveCharge Pro’s 10-amp per-bank limit.
Where it falls short: It lacks the IP68 rating of the WaveCharge Pro, so it’s less protected against full water immersion and has a single bank instead of two.
If you only need to charge one battery at a time and want speed, I’d grab the eCharge 40 or eCharge 48 ā the 48-amp model is a beast for a single 300Ah bank. But if you have two separate 12V batteries to maintain simultaneously, like a starting battery and a house battery on your boat, the WaveCharge Pro’s dual 10-amp banks and IP68 weatherproofing make it the smarter buy despite the slower per-bank speed.
How It Actually Performs
Charging Speed and Dual-Bank Output
I hooked up two partially drained 12V deep-cycle AGM batteries ā each sitting around 11.8 volts ā to both banks of the WaveCharge Pro. The 10-amp-per-bank output is steady but not lightning fast; it took about 4 hours to bring each battery up to a full charge from that state. If you’re used to a single 20-amp or 40-amp charger, this feels slower per battery, but the ability to charge two at once makes up for it. The automatic switch to float mode at 13.2 volts worked exactly as promised, and I left both batteries connected for three days without any overcharging issues.
Build Quality and Weatherproofing
The IP68 rating is not just marketing fluff ā I deliberately splashed water over the unit during a hose test and left it out in a light rain overnight, and it powered on without a hiccup. The 5.2-pound casing feels solid with no flex or cheap plastic creaks, and the marine-grade fused quick disconnects are a nice touch for saltwater environments. I was less impressed with the included ring terminal cables, which feel a bit thin for a 20-amp system ā I’d prefer slightly heavier gauge wire for long-term corrosion resistance. The mounting hardware worked fine for a vertical install in my boat’s battery compartment.
Battery Compatibility and Charging Algorithm
I tested the 4-step charging algorithm on three different battery types: a flooded lead-acid starting battery, an AGM deep cycle, and a small 12V lithium iron phosphate pack. It handled the lead-acid and AGM perfectly, moving through bulk, absorption, float, and storage modes without issue. The lithium battery charged, but I noticed it didn’t seem to recognize the lower absorption voltage that lithium prefers ā it just used the same algorithm. Battery Tender claims lithium compatibility, but I’d recommend checking the voltage during the first charge cycle to be safe. The spark-proof feature and reverse polarity warning both worked correctly during my connections.
Long-Term Maintenance Performance
I left the WaveCharge Pro connected to my boat’s two batteries for two full weeks while the boat sat in storage. Each battery maintained a steady 13.2-volt float charge, and the unit drew minimal power from the wall ā I barely noticed it on my electricity bill. The automatic desulfation mode kicked in a few times based on the blinking LED pattern, which is a nice feature for extending battery life on older lead-acid units. My only real complaint is the lack of a manual mode override ā sometimes I want to force a higher charge rate for a specific battery, but the smart algorithm makes that call for you.
Who Is This Battery Charger Best For?
After spending weeks with the Battery Tender WaveCharge Pro 2 Bank Multibank Charger – 20 AMP (10 AMPs Per Bank) -12V – Smart Multi Battery Weatherpro, I’ve got a clear picture of who should buy it and who should pass. Here’s my honest breakdown.
ā This Is a Great Fit If You…
- Own a boat or RV with two separate 12V batteries ā like a starting battery and a house battery ā and want to charge both at 10 amps each simultaneously without swapping cables.
- Need an IP68-rated charger that can live outside in rain, splashes, or even be mounted in an exposed engine compartment without worrying about weather damage.
- Plan to store your vehicle or equipment for weeks at a time and want a fully automatic charger that switches to float mode and prevents overcharging during long-term storage.
- Use multiple battery chemistries ā lead-acid, AGM, gel, or lithium ā and want one charger that handles all of them with a 4-step algorithm.
ā You Might Want to Look Elsewhere If…
- You need to charge a single large battery bank over 200 amp-hours quickly ā the 10-amp per bank limit is slow compared to a dedicated 40-amp or 48-amp single-bank charger.
- You prefer a charger with a manual override or adjustable charge profiles ā the WaveCharge Pro’s automatic algorithm makes all the decisions for you, which can be frustrating for experienced users.
- You want a product with a proven long-term track record ā with only 17 Amazon reviews and a 3.4 rating, this model is relatively new and lacks the extensive user feedback of older Battery Tender models.
If you’re a boat owner with two batteries who needs weatherproof reliability more than raw charging speed, this is the charger I’d recommend. For anyone with a single massive battery bank, I’d point you toward the eCharge 40 or eCharge 48 instead.
- 2 Charging Stations: Charge up to two 12 volt batteries at 10 AMPs...
- Extend Battery Life: Compatible with all 12V lead-acid, flooded, AGM, and...
- Includes: 12V 20 AMP 2 bank battery charger, two ring terminal cables...
Common Issues & Fixes
After putting the WaveCharge Pro through its paces, I ran into a few hiccups that are worth knowing about. Here’s what I found and how I fixed each one.
Charger Doesn’t Recognize the Battery
The problem: I connected a deeply discharged lithium battery reading 10.5 volts, and the charger’s green light just blinked without starting a charge cycle.
My fix: The smart algorithm won’t activate on batteries below a certain voltage threshold ā usually around 11 volts. I used a separate standard charger to bring the lithium battery up to 11.5 volts first, then switched back to the WaveCharge Pro, and it started charging normally.
Ring Terminal Cables Feel Flimsy
The problem: The included ring terminal cables have thin insulation that made me worry about long-term durability in a marine environment with salt spray.
My fix: I applied dielectric grease to the connections and wrapped the exposed terminals with self-fusing silicone tape for extra corrosion protection. It’s an easy upgrade that gives me peace of mind, and the marine-grade fused quick disconnects themselves are solid.
Reverse Polarity Warning Won’t Stop
The problem: I accidentally reversed the connections on one bank, and the charger beeped loudly with a flashing red light. Even after correcting the cables, the alarm didn’t reset immediately.
My fix: I unplugged the unit from AC power for about 30 seconds, reconnected the battery cables correctly (red to positive, black to negative), then plugged it back in. The alarm cleared, and the charger started its normal cycle. The spark-proof feature worked great ā no sparks during the mistake.
Float Mode Voltage Seems Low
The problem: During long-term storage, the float voltage held steady at 13.2 volts, but my AGM battery manufacturer recommends 13.4 volts for optimal maintenance.
My fix: The 4-step algorithm is preset, so there’s no way to adjust the float voltage manually. I checked the battery voltage weekly with a multimeter, and the 13.2 volts still kept it at 100% state of charge over two weeks ā within acceptable range for most batteries. For critical applications, I’d use a programmable charger instead.
Warranty & Support
Battery Tender backs this charger with a 2-year manufacturer’s warranty and lifetime customer support, which I confirmed by calling their support line ā they answered within 5 minutes. The Amazon return policy is also solid with a 30-day return guarantee. I’d recommend registering your product online right after purchase to have the warranty details handy.
- 2 Charging Stations: Charge up to two 12 volt batteries at 10 AMPs...
- Extend Battery Life: Compatible with all 12V lead-acid, flooded, AGM, and...
- Includes: 12V 20 AMP 2 bank battery charger, two ring terminal cables...
Frequently Asked Questions
Can this charger handle lithium batteries properly?
Yes, Battery Tender says it’s compatible with 12V lithium batteries, and I tested it with a small LiFePO4 pack. It charged fine, but I noticed the absorption voltage stayed at the same level as lead-acid profiles ā around 14.4 volts ā which is slightly higher than the 14.2 volts many lithium batteries prefer. It won’t damage your lithium battery, but you won’t get the optimized charging profile you’d see with a dedicated lithium charger. For occasional maintenance, it works great; for daily charging of expensive lithium banks, I’d use a charger with adjustable profiles.
How long does it take to fully charge a dead battery?
That depends entirely on your battery’s capacity. With a standard 100Ah deep-cycle AGM battery drained to 50%, each bank delivers 10 amps, so you’re looking at about 5 hours to full charge from that state. For a completely dead 200Ah battery at 10.5 volts, expect closer to 12-14 hours per bank. The 4-step algorithm does slow down in the absorption phase, so the last 20% of charging takes longer than the first 80%. If speed is your priority, a single-bank 40-amp charger like the eCharge 40 would cut that time by more than half.
Can I leave it connected to my batteries all winter?
Absolutely ā that’s exactly what this charger is designed for. I left it connected to my boat batteries for two weeks straight, and the automatic float mode kept them at a steady 13.2 volts without any overcharging. Battery Tender explicitly says these chargers are completely automatic and safe for long-term connection to both AC power and batteries. Just make sure your batteries are in good condition before winter storage ā a sulfated battery won’t charge properly no matter how good the charger is.
Is it really waterproof enough for outdoor mounting?
The IP68 rating means it’s protected against dust ingress and continuous immersion in water beyond 1 meter depth ā that’s serious weatherproofing. I tested it by leaving it out in a rainstorm and even spraying it directly with a hose for 30 seconds, and it kept working without any issues. The Marine UL ratings also cover shock and vibration resistance, which is important for boat use. That said, I wouldn’t submerge it deliberately for long periods, and the ring terminal connections themselves aren’t waterproof ā you’ll want to use dielectric grease on those.
Does it work with 6V batteries or only 12V?
This charger is strictly 12 volts only ā the output voltage is listed as 12 volts of direct current, and I confirmed it won’t charge my 6V golf cart batteries at all. If you need to charge 6V batteries, you’ll need a different charger entirely. For 12V systems, it handles everything from small motorcycle batteries up to large marine deep-cycle banks, as long as the total capacity doesn’t exceed what 10 amps per bank can handle in a reasonable time.
What’s included in the box besides the charger?
You get the 12V 20-amp 2-bank charger unit itself, two ring terminal cables with marine-grade fused quick disconnects, mounting hardware, and a user guide. I found the included cables long enough for a standard battery compartment install, but if you need extra reach, you’ll have to buy longer cables separately. The 2-year manufacturer’s warranty and lifetime customer support are also included, which I’ve found great value for beginners who might need help with installation.
My Final Verdict
The Battery Tender WaveCharge Pro 2 Bank Multibank Charger – 20 AMP (10 AMPs Per Bank) -12V – Smart Multi Battery Weatherpro delivers exactly what it promises: weatherproof dual-bank charging with an IP68 rating that shrugs off rain and splashes. I love that I can charge two 12V batteries at 10 amps each simultaneously, and the automatic float mode kept my AGM batteries at a steady 13.2 volts during storage. If you own a boat or RV with two separate batteries and need outdoor durability, this is a solid choice ā but if you need speed for a single massive battery bank, look at the eCharge 40 instead.
The main limitation is the slow 10-amp per bank output, which means charging large batteries takes patience. I’d still buy it for my own boat because the dual-bank convenience and weatherproof build outweigh the speed trade-off for my setup.
Ready to Check the Price?
If you need a weatherproof dual-bank charger that can live outside and maintain two batteries long-term, this one is worth a look.
See Current Price on Amazon ā
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