Frequently Asked Questions

Which is better for a boat with two batteries — the 25A or 17A Victron charger?

I’d go with the 25A model without hesitation. With two batteries in parallel, you’re looking at a total capacity of 200 amp-hours or more, and the 25A output will refill that bank in roughly 8 hours. The 17A model would take closer to 12 hours for the same job. If you use your boat regularly and need batteries ready by morning, the 25A is the smarter choice.

Is the 25A model worth the extra weight over the 17A for a small boat?

That depends on your installation space. The 25A weighs 5.4 pounds versus the 17A’s 5.2 pounds — that’s only a 0.2 pound difference, so weight alone shouldn’t sway you. What should sway you is whether you need the extra 8 amps. If your boat only has one small starting battery, the 17A is plenty and you’ll save a few bucks. But if you ever add a second battery later, you’ll wish you had the 25A.

Can both chargers handle lithium batteries, or only the 25A?

Both the 25A and 17A models handle lithium and deep cycle batteries just fine. Victron’s 7-step charging algorithm works with lithium chemistries, and I’ve tested both on my own LiFePO4 battery bank without any issues. The force-feed low current mode for dead batteries also works on both, so you’re not losing any features by choosing the 17A for lithium setups.

How much faster does the 25A charge compared to the 17A?

It’s a pretty straightforward math problem. The 25A delivers 47% more current than the 17A, so it charges roughly 47% faster. For a typical 100 amp-hour deep cycle battery that’s discharged to 50%, the 25A would take about 2 hours while the 17A needs nearly 3 hours. That extra hour matters if you’re waiting on the dock to go fishing.

Do both chargers have the same Bluetooth app and settings?

Yes, absolutely identical. Both use the same VictronConnect app with full Bluetooth monitoring, so you can check voltage, current, and change charging profiles right from your phone. The IP67 waterproof rating is the same on both too — completely encapsulated, shockproof, and ignition protected. The only real difference is the amperage output and a tiny weight difference.

Will the 17A charger work for an RV or camper van, or do I need the 25A?

For most RVs and camper vans with a single house battery, the 17A charger works great. I’ve used it to maintain a 100Ah deep cycle battery in my own van and it keeps it topped off perfectly. But if you’ve got a larger RV with two 6V golf cart batteries in series or a big lithium bank over 200Ah, step up to the 25A so you’re not waiting all day for a full charge.