2023 Model 12V to 12V DC to DC Chargers 25A | 40A | 70A | 120A models + Remote Control (optional)
12V to 12V DC to DC Chargers 10A | 25A | 40A | 70A | 120A models - E-Marking
New BB1225 - video - available now
New BB1210- video - the benefits of 10A current limiting - charging portable power banks
10A | 25A | 40A | 70A | 120A | 200A models available now.
We can ship to the USA
Remote control BBR - Optional remote
- Buck Boost design, offering high efficiency (95-98%)
- Simple installation and setup
- Current limiting charger
- Lithium safe
- BB1240 Bidirectional w/ reverse charging and jump start assistance mode | 12V 40A (550W output power)
- BB1270 Bidirectional w/ reverse charging and jump start assistance mode | 12V 70A (930W output power)
- BB12120 Bidirectional w/ reverse charging and jump start assistance mode | 12V 120A (1620W output power)
BBW1270 - waterproof version of the BB1270 - weighs about 1KG more. Several available.
Smart Alternator/Euro 6+ compatible
- Ignition feed or Vibration Sense modes
- 6 preset battery types
- 6 self recovering protections
- Low temperature trip for Lithium Ion batteries
EV - Electric Vehicle Compatability - 3 reasons to install a BB instead of direct cabling / relay
Underneath the bonnet 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.
Benefits of BB installation with EV
- 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! The 2022+ Tesla Model 3 and Y have a DC DC converter that sits at 15.5V. Thus, to convert this voltage to a conventional 12V or 24V battery charging profile requires converting.
BB1240 Reverse Charging Feature.
The BB1240 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.
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Battery to Battery Charger Remote Control - BBR PLEASE NOTE - BBR works best with brand new models in stock now (June 2022 onwards). If you have a BB1240/70/120 from before this date, you may have to send the BB back to use for latest firmware. As this is a new item, it has features that require BB firmware modifications. (Optional)
BBR comes with 4m extension cable What does the BBR offer?
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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: |
 E24 - BB1270 - E-Marking certificate
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BB1270 Input voltage range 9V-16V Continuous Rated output power 64A at 14.51V ~930W Continuous Rated input power 71.75A at 13.61V ~976W Quiescent current 5mA Efficiency rating 95-98% Self recovering protections: under voltage protection input over voltage protection output over voltage protection over current protection charge over temperature Operational Temperature -20 Deg C -> 60 DegC Approval CE | UKCA E-Marking 24*10R06/01*3789*00 Cooling method Thermostatically Controlled Variable low speed fan Dimensions 200mm x 130mm x 56mm Weight 1.0Kg |
BB12120 Input voltage range 9V-16V |
| BB1210 Input voltage range 9V-16V Continuous Rated output power 10A at 14.41V ~144W Continuous Rated input current 11A at 13.63V ~150W Quiescent current 5mA Efficiency rating 98% Self recovering protections: under voltage protection input over voltage protection output over voltage protection over current protection charge over temperature Operational Temperature -20 Deg C -> 60 DegC Approval CE | UKCA E-Marking 24*10R06/01*3789*00 Cooling method Thermostatically Controlled Dimensions 120mm x 130mm x 56mm Weight 0.6Kg |
| BB1225 Input voltage range 9V-16V Continuous Rated output power 24A at 14.41V ~345W Continuous Rated input current 26A at 13.68V ~355W Quiescent current 5mA Efficiency rating 98% Self recovering protections: under voltage protection input over voltage protection output over voltage protection over current protection charge over temperature Operational Temperature -20 Deg C -> 60 DegC Approval CE | UKCA E-Marking 24*10R06/01*3789*00 Cooling method Thermostatically Controlled Dimensions 120mm x 130mm x 56mm Weight 0.6Kg |
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BB1240 Input voltage range 9V-16V Continuous Rated output power 38A at 14.41V ~550W Continuous Rated input current 42A at 13.68V ~575W Quiescent current 5mA Efficiency rating 95-98% Self recovering protections: under voltage protection input over voltage protection output over voltage protection over current protection charge over temperature Operational Temperature -20 Deg C -> 60 DegC Approval CE | UKCA E-Marking 24*10R06/01*3789*00 Cooling method Thermostatically Controlled Variable low speed fan Dimensions 165mm x 130mm x 56mm Weight 0.8Kg |
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, BB1270 w/ BB1240 or BB12120 etc.. it does not matter.
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.
Turning off the reverse charging feature, you can! Please watch the video