Bahoma battery connection tips and advice

Bahoma battery connection tips and advice

Troubleshooting issues:
-Receiver doesn't sync unless bahoma battery is squeezed - failure to sync.
-Receiver shuts down when throttle is applied.

These problems care caused by a poor, high resistance electrical contact at the battery's Bahoma connector. Bahoma stands for BAttery HOlder using MAgnets - BAHOMA. It is a convenient connector for micro RC models, enabling you to connect a cell to a very small model without worrying about physically crushing the airframe. Bahoma connectors do have a few inherent weaknesses. It can be helpful to have knowledge about these characteristics so that you can cope with and prevent any problems.

If you have a problem syncing your receiver, try syncing up with a different cell - the problem may go away. It can be helpful to have an extra cell to diagnose the problem. The fact that it powers up without having to squeeze has us thinking that probably there is a high resistance contact at the magnet terminals. When you squeeze it together, you are making it a better electrical contact, and the receiver then can sync up. The magnets of the Bahoma connector must be periodically maintained with a bit of cleaning. If they get dirty, you can have this symptom - failure to sync up. If you try a different cell and the problem is still there, even with a different cell, it's probably not the battery that is the problem, it might be dirty connector magnets on the receiver side. If the problem goes away when you try another cell - then the cell is the chief suspect - dirty bahoma magnets or maybe even bad cell chemistry.

If your receiver starts up and syncs up fine, but you find that when you apply full throttle of your motor, the receiver quits or stops functioning, probably the motor is being starved for current - there is a high resistance connection and the battery is not able to supply enough current for the motor and receiver computer, so the receiver computer stops functioning in this circumstance, and will need to have the battery connection checked again. This is called a "brownout". It is always good practice to check your throttle of your model before launching it - just to verify that you have a good battery to receiver connection.

When you squeeze the battery onto the receiver, you do run the risk of bending the PCB (printed circuit board), if this is flexed too much, it can break a contact or a trace - broken trace. You can try cleaning the magnet terminals of the bahoma cell and the receiver magnets - lightly abrade them, or wipe them with alcohol on a swab or other probe like a stick of balsa or a matchstick, and see if it helps. Shine those magnets up - it can help a lot of you keep them clean.

Fingerprint oils, dust and other crud can cause resistance in the Bahoma connection, and unlike conventional connectors which benefit from friction cleaning the contacts when they are connected, Bahoma does not. To clean them use the point of a hobby knife in a swirling motion, the weight of the handle is all the pressure that is needed. You only want to scour it, we don't want the plating scraped off of the magnets if we can help it.

Use a cotton tipped swab or a round toothpick snapped in half and then soaked in rubbing alcohol to polish away the crud.

Use extra caution when cleaning the magnets on the receiver, as excessive force can fracture the PCB.
Trying a different specimen of bahoma cell might tell you if you are on the right track or not. If you try a different cell and it still has the same symptoms, you may indeed have a broken PCB trace to one of the components or some other problem.
Repair or Replace is the next course of action then. If you wish to have Plantraco to try and repair it for you, we usually have a minimum flat shop rate of $20.00 for repair service type stuff, and it can be higher for items like airframe repair and replacement - depending on the complexity. Sometimes we'll just replace it for you rather than repair a broken PCB.

If any of the startup LED and audible tone sequences are confusing to you - you should read the HFX900 manual, which explains this in detail.