Will it charge a lithium battery safely?

Yes. The charger supports lithium as well as lead-acid chemistries and uses multi-stage charging. It also claims to revive lithium batteries that were deeply discharged or left in storage.

Can I use it with a solar panel?

No. It is a DC-to-DC charger that pulls from an alternator or generator, not a solar charge controller. A separate MPPT controller is needed for panels.

How much current does it deliver?

It is rated at 40A at 12V, which is enough to recharge a sizable auxiliary bank during a day's driving. Check that your alternator and wiring can handle that load.

Does it need extra cooling?

It has a built-in fan that speeds up as the unit warms, so it manages its own heat. Still mount it where air can move around the body.

What protections does it have?

Over-temperature, short circuit, over-voltage and under-voltage protection are built in, according to the maker.

Is it hard to install?

The compact case is meant for tight spaces, but this is a bare charger. Plan on supplying your own fusing, cabling and mounting hardware.

Where is the KFFKFF 12V 40A DC to DC Battery Charger cheapest?

At Walmart, for $97.99, as of our latest check.

What do buyers say about the KFFKFF 12V 40A DC to DC Battery Charger?

Rated 5 out of 5 from 1 ratings.

KFFKFF 12V 40A DC to DC Battery Charger

Best price now

$97.99at WalmartChecked Nov 12

Prices are checked against each store and labelled with when.

Visit Walmart

KFFKFF 12V 40A DC to DC Battery Charger

Best price now

$97.99at WalmartChecked Nov 12

Prices are checked against each store and labelled with when.

Visit Walmart

Ask our agent about this product

It checks today's price at every store, compares the alternatives and answers in about a minute.

Price facts

Last seen at $97.99 at Walmart on Nov 12.

Our take on the KFFKFF 12V 40A DC to DC Battery Charger

The KFFKFF 12V 40A DC to DC charger takes power from a vehicle's alternator or a generator and feeds it to an auxiliary battery bank, which is what RV and boat owners need to keep a house battery charged while driving. It handles both lead-acid and lithium chemistries and uses multi-stage charging, with a temperature-controlled cooling fan and protection against over-voltage, under-voltage, short circuit and overheating. It is a bare charger rather than a full kit, so it competes with established DC-to-DC units on the strength of its 40A output and compact footprint rather than on brand support or app features. Buyers who want a simple, high-current charger for a camper, van or boat aux bank are the target; those who need solar input, Bluetooth monitoring or detailed charge profiles should look at more feature-rich rivals.

Best forRV and camper owners charging a house battery from the alternatorBoat owners maintaining an auxiliary bank while underwayVan and overland builds with a second batteryReviving deeply discharged or stored lithium batteries

Pros

40A output moves a lot of charge for its size
Works with both lead-acid and lithium batteries
Multi-stage charging profile
Temperature-controlled cooling fan
Over-voltage, under-voltage, short circuit and over-temperature protection
Compact body fits tight install spaces

Cons

No Bluetooth or app monitoring
No solar input; alternator or generator source only
Limited brand track record compared with Renogy or Victron
Installation hardware and wiring not spelled out

KFFKFF 12V 40A DC to DC Battery Charger prices at every store

WalmartNew
In stockSold by KFFKFF Tools & Hardware USReturns: Sold by a Walmart Marketplace seller; returns go to the seller under the seller's returns policy.
$97.99Checked Nov 12
Visit Walmart

About the KFFKFF 12V 40A DC to DC Battery Charger

This 12V 40A DC to DC battery charger recharges an auxiliary battery from the vehicle's power while you travel. It works with both lead-acid and lithium batteries, and it is intended for RVs and boats.

It uses multi-stage charging and has high temperature, short circuit, over voltage and under voltage protection. A built-in cooling fan responds to the charger's temperature to help prevent overheating. It can also recharge lithium batteries that have been over-discharged or left in storage.

The charger is made to fit into tight spaces for easy installation. A two-color indicator shows the charging status.

Model: SDC-40A
Color: Black
Input voltage: 12V
Input range: DC 8V-16V
Charging current: 40A
Charging voltage: 13.2V-14.7V (lead-acid), 12.6V-14.6V (lithium)
Max output: 500W
Battery types: Lead-acid and lithium
Casing: Aluminium alloy
Operating temp: 4 °F to 122 °F (-20 °C to 50 °C)
Weight: 3.31 lbs (1.5 kg)
In the box: 1 x DC to DC charger, 4 x fuses, 1 x user manual

Specifications

color: BlackSource

Questions and answers

Will it charge a lithium battery safely?: Yes. The charger supports lithium as well as lead-acid chemistries and uses multi-stage charging. It also claims to revive lithium batteries that were deeply discharged or left in storage.
Can I use it with a solar panel?: No. It is a DC-to-DC charger that pulls from an alternator or generator, not a solar charge controller. A separate MPPT controller is needed for panels.
How much current does it deliver?: It is rated at 40A at 12V, which is enough to recharge a sizable auxiliary bank during a day's driving. Check that your alternator and wiring can handle that load.
Does it need extra cooling?: It has a built-in fan that speeds up as the unit warms, so it manages its own heat. Still mount it where air can move around the body.
What protections does it have?: Over-temperature, short circuit, over-voltage and under-voltage protection are built in, according to the maker.
Is it hard to install?: The compact case is meant for tight spaces, but this is a bare charger. Plan on supplying your own fusing, cabling and mounting hardware.
Where is the KFFKFF 12V 40A DC to DC Battery Charger cheapest?: At Walmart, for $97.99, as of our latest check.
What do buyers say about the KFFKFF 12V 40A DC to DC Battery Charger?: Rated 5 out of 5 from 1 ratings.