12V 30A DC to DC Charger with MPPT for Solar & Alternator Input - Smart On-Board Battery Charger for RV, Marine, Car - Charge AGM, Lithium, Gel, Flooded Batteries

I’ve been running this Renogy DC-DC MPPT combo charger in my overland truck build for a while now, and it’s been solid overall, but there are a few things worth knowing before you buy. First off, build quality is great — the unit feels durable and the terminal screws are easy to torque without stripping, which I appreciated during install. Charging performance is strong once it kicks in, but that’s where it gets a little fussy. The charger doesn’t begin charging until the battery drops below about 12.6 volts (around 60% state of charge for lithium), which can be frustrating if you’re hovering mid-range. I personally don’t like dropping my LiPo that low just to trigger charging. Once it does start, though, it pushes a nice solid boost up to 14.4V. The charger defaults to prioritizing alternator input over solar, which is great for truck setups, but solar still does a decent job throughout the day. That said, if your battery stays above the boost return voltage (around 13.2V), the system may just sit idle thinking the battery is full — even when it’s not. This is especially noticeable with lithium batteries that hold a flat voltage curve and can “trick” the controller into staying off. If you want full control, the Renogy Bluetooth module is an absolute must. Without it, you’re stuck on the default presets, but with it, you can fully customize the charge profile, adjust start/stop voltages, and disable float — making it way more compatible with LiPo or LFP battery setups. Overall, the charger works really well once configured correctly, especially for dual-input rigs, but the default behavior out of the box is a bit rigid for lithium users. If you’re building a solar-plus-alternator system and can get the Bluetooth dongle, this is a reliable and efficient charger that’s worth the money.

Fairly basic charger other than having solar input as well as DC to DC. Bluetooth module is sold separately, not included. It's very helpful to have, and required to access all the settings of this charger. A bluetooth module should have been included or built into the unit if it is required to access all functions. Charger works well, though it has some quirks. Doesn't start charging unless the battery voltage is low, does not automatically act as a maintainer, and doesn't top off lithium batteries very well. Does work better for some other chemistries, and it's somewhat reasonably priced for having solar input.

This DC to DC charger ended up being the perfect upgrade for my partner's setup. The MPPT solar input is super efficient, and the alternator charging is smooth and consistent with zero voltage drama. It automatically handles AGM, lithium, and flooded profiles without him having to tweak anything. Runs cool, installs easily, and just works the way a smart charger should. Solid, dependable, and definitely worth it. Recommend!