Part # BB12120 DC to DC Smart Battery Charger.

Why wait to arrive at your destination to plug in your battery charger?

Now you can smart charge the housebank in your Boat, Tow Camper, Boat in tow, Sprinter or Custom Van while driving down the road or on the water. This charger correctly calculates the batteries or bank of battery charging needs and boost charges with the right charging algorithm for your battery anytime the boat or vehicles alternator is running. It also goes into lower float voltage when the battery is full.

DC Powered Smart Charger, perfect for smart charging your auxillary battery bank in a Truck, Mercedes Sprinter or Ford Transit van, Doesnt have the limitations of a tradional relay.

- Buck Boost design, offering high efficiency (95-98%)
- Simple installation and setup
- Current limiting charger
- Lithium safe
- Smart Alternator/Euro 6+ compatible
- Ignition feed or Vibration Sense modes can be used for turning the charger on and off.
- 6 preset battery types
- 6 self recovering protections
- Low temperature trip for Lithium Ion batteries

- part # BB1225 Bidirectional w/ reverse charging and jump start assistance mode | 12V 25A (340W output power)
- part # BB1240 Bidirectional w/ reverse charging and jump start assistance mode | 12V 40A (550W output power)
- part # BB1270 Bidirectional w/ reverse charging and jump start assistance mode | 12V 70A (930W output power)
- part # BB12120 Bidirectional w/ reverse charging and jump start assistance mode | 12V 120A (1620W output power)
- part # BB12200 Availavble soon
- part # BB1224120 Limited Quanties Available now
- part # BB1248120 Available Soon
- BB24v to 24v Under Development
- BB24v to 48v Under Development

Why adjust the current limit?

The default current setting for the BB range is 100% - meaning that the performance default is full power. If you wish to reduce the performance of the BB, here you can set to 85% or 65% charge rate. Examples of why you may wish to reduce performance:

1) if you have solar panels and the weather is good, by reducing the power of the BB, you shall conserve fuel.
2) The alternator is better suited running at slightly lower current than what was expected or you don't want the alternator to work as hard.
3) It may be recommended by your battery supplier to charge the battery up at a slightly lower current. If one of your lithium batteries within your leisure battery bank fails, you may be exceeding the C rating of the remaining batteries.
4) future proofing. If you have installed a high powered BB, in the assumption that one day you shall put a larger alternator on and/or more batteries in your system. You can reduce the power for the immediate install and increase the performance of the unit at a later date.

EV - Electric Vehicle Compatability -
Reasons to install a BB instead of direct cabling / relay & benefits of BB installation with EV

Underneath the hood of EVs is the positive and negative 12V terminal that leads from the high V -> low V DC DC converter to the 12V battery. There is usually a 12V positive busbar and a 0V negative post. One of these positive feeds leads to the 12V battery. The 12V post that leads to the 12V battery would be where you install the BB along with the common negative post.

The high voltage to low voltage DC DC converter shall likely be itself current limiting. However, the vehicle has uses for this current, albeit, not all of this current all of the time.

- The BB isolates the EV 12V battery from the 12V leisure battery, therefore you shall NOT drain the 12V EV battery. If you drain the 12V EV battery your EV will not start.

- The BB has a maximum current draw. A good estimate is to rate your BB to approximately 25-50% of the current rating of your DC DC converter. This allows the converter to provide the power to run your obligatory loads (steering, lights, stereo, air con etc) and surplus to go in to your 12V auxiliary battery. For example, if your converter is 190A rated, use a BB1270 - it shall provide ~60/70A to charge. If the full use of the converter is being used by all ancillaries the voltage shall drop across the 12V system and the BB shall naturally reduce performance and eventually turn off during that episode when there is a high power demand. The BB shall turn on again when the voltage climbs.

- Charging lithium batteries shall likely exceed the charge rating. If your converter is 200A rated but your lithium battery can only handle up to 100A - the converter shall try and provide 200A but the battery(s) BMS shall trip out. The benefit of the BB is that it shall reign in the current to whatever BB you choose.

- You shall get the correct charge voltages at the 12V auxiliary battery. Some DC DC converters shall sit at 14.7V all the time, which may be too high!

Reverse Charging Feature:

The BB12120 is able to charge in both directions. Provided there is over 13.2V on the leisure battery (13.5V if lithium) and the starter battery is below 13V the BB shall allow approximately half current (~20A) to flow back to the starter battery up to about 13.4V (float voltage). It simply allows the starter battery to remain topped up when there is surplus energy in the domestic battery. This feature will NOT drain your domestic battery - it simply takes surplus. Once your alternator / engine turns on or you provide the BB with an ignition signal the BB reverts to normal charging of the leisure battery. This mode can be disabled, but is on as default.

This is ideal for allowing the starter battery to remain topped up when you have solar / wind / charger - charging up your leisure battery.

Paralleling multiple battery to battery chargers together?

There are no problems installing multiple BBs together in parallel to increase the power. For example, you can parallel a BB1240 with a BB12120 to get 160A of charge current. Likewise, two BB1270 units for 140 amps total or two BB12120 units for total of 240 amps directed to housebank charging from one alternator or two alternators as input sources is a common application.

Benefits:

1) Redundancy, having multiple DC-DC chargers can help with reduncancy. If one was to get damaged, the other BB(s) shall continue charging.

2) fine tuning the current. As each BB has 3 different power levels, adding multiple BBs together gives you 6, 9, 12 etc.. different power levels. For example, if you wanted 90A you could get a BB1270 and a BB1240 and set the power levels to 85% each via the BBR remote (to give you approximately 90A). Thus, giving you large levels of flexibily to hone in to a specific charge current.