C-Tek
I use a C-Tek on my street rod to keep her charged. This is the best unit I have ever used. It charges and then tends all digitally. It is great. I don't work for them. They cost about $69
The Multi US 3300 battery charger, the best-selling charger in Europe today. CTEK MULTI US 3300 is a strong multi-tasker that can handle all but the largest vehicles. Particularly well suited for automotive use, the MULTI US 3300 offers outstanding recharging performance - the car is back on the road typically in under an hour. A unique cold temperature mode enables faster recharging, even in the coldest winter conditions.
The Multi US 3300 is part of the CTEK collection of "the smartest battery chargers in the worldfont size="1">", an ideal choice for cars, motorcycles, snowmobiles, ATVs, personal watercraft and lawn tractors, as well as smaller campers and boats.
The Multi US 3300 utilizes Switch Mode Technology, a 4-cycle intelligent process for perfect battery maintenance and charging.
Switch Mode "Intelligent" Technology
Desulfation: Recovers or "wakes" a sulfated or under-charged battery.
Bulk Charge: Begins charging at 0.8/3.3A.
Absorption: Applies peak charge at 14.4/14.7V until fully charged.
Pulse: Sends out current pulses for charge maintenance.
As compared to competitive battery chargers, the Multi US 3300 is virtually foolproof to connect, wherever the battery is located. The Multi US 3300 essentially eliminates any fear or apprehension about charging a battery because of its patented protection system against sparks, short circuits and reverse polarity. Approved for outdoor use, the charger can be used in any weather conditions.
Three step, fully automatic (IoUoUp) switch mode battery charger for all 12V lead-acid batteries, 1.2-120Ah
Features and Benefits
Three step, fully automatic switch mode model
Charges lead-acid batteries (Wet, MF, Gel and AGM) from 2Ah to 90Ah
Maintenance pulse charging increases battery life and gives superb performance
Charges even drained batteries
Pulse recover of slightly sulphated batteries
Three unique charging modes for use on small batteries, large batteries and a special cold mode that is also suitable for AGM batteries.
Low back current drain, low ripple and input voltage independent (85-125V)
High efficiency: 85%
Delivered with two interchangeable connection leads, one with clamps, and one with eyelet terminals
The charger can be connected for months, ideal for seasonal vehicles
Compact design with mounting holes for permanent assembly
2 year warranty
The CTEK MULTI US 3300 is specifically recommended for Optima Red Top batteries.