Electrical Issue

[Bowches]

Hi all,

My CBR 400 used to have this issue that when I turned on the lights at night time and the bike was running/moving, the battery would get weaker and weaker and the lights would die and the whole bike would switch off.

Then I changed the rectifier which solved the problem 50%. I'm happy that the bike does not shut down now when I put the lights on and the battery does not go dead when the bike is moving/running.

Although, after running for say an hour or so...if I stall (my bike is not idling), the batteries power goes down very quickly when the engine is not running and I have to quickly turn off the lights so that it does not eat my battery power in order to start the bike again.

Basically the bike's lights are working when the bike is running/moving...but if I stall and need to press the starter button to start the bike again....the batteries power goes down very quickly and I have to hurry to turn it back on again.

[Bowches]

I also dont know why it is not idling.....what are the causes for not idling. I have to hold the throttle slightly so that the revs do not go below 1300 RPM.

[Davez29]

I would be checking the battery. Pehaps your old rectifier fried it. Buy a decent make, personally i use Varta funstart (i think i have used this battery since 2013, no problems) as if you can locate them on ebay there maybe only a couple of quid difference in price between that and an unknown make. Varta come from the same factory as Yuasa batteries.

Also check the alternator, im not certain so check first for confirmation but i think the three yellow wires before the rectifier should be outputting 50 volts AC at 5000rpm. Also do the other tests mentioned in the Haynes manual..

Believe me i have been there with the same problems several years ago. Its a pain but solvable.

[Bowches]

ok thanks alot Davez29

[Bowches]

The battery I am using is the Lithium ion light weight batteries on sale on Ebay. I dont think thats the issue but I will have a look. I bought a original Honda Rectifier from Ebay, also I will put on original 35W bulbs back on the bike instead of the current 55W Halogen H4 bulbs....it might make a difference.

[Davez29]

I have not used one of these lithium batteries so cant say if they are good or bad for everyday riding, hopefully someone can help out there. The Varta I use is an AGM type and does do the job well but I guess lithium maybe the way forward, the thing is I need reliability and cant see myself changing anytime soon to an unknown source, especially as my lights are permanantly on. Although it would be a bit lighter carrying as a spare in your tail compartment on long trips as I always do nowadays, something I have always done since my bad charging days. I cant afford to get stuck 30 miles away at work with a duff battery.

You have a new rectifier but it seems that even new Honda replacements can fail quite quickly, sadly. So in the future if you need another look for a Mosfet type replacement instead of the Shunt type you have now, these run a lot cooler. They can be obtained from places such as Electrex World but look around as many three wire units will fit the 29, usually a connector change is required. I know that I could fry an egg on my old shunt type rectifier, my Mosfet rectifier barely gets tepid as the technology works differently.

With the summer aproaching I guess the lower wattage bulbs will help but if you can fix it, do it, as those 35w ones are pathetic on low beam out of town.

Best get a multimeter and do those tests and test your bike.

Also I used to use one of those LED charge lights, usually on ebay, that you wire in. These change colour and give you an indication on what your charging system is doing. The seller I got mine off lives in Scotland and he will program the chip to whatever you want, basicly a traffic light system, for instance, Green 14.5v all good, Orange 13v under charge, Red 15v overcharge and various flashing modes for more info. Although his standard set up is good enough.

edit; one other thing, although not a fix if you dont have one get an Optimate charger, v3 or v4 is good enough for normal lead acid/agm batteries, v4 will charge at a slighly higher rate. More important to you, they do a version for your style Lithium although check the specs are right for you if considering buying. this will help ensure you have a charged battery to begin with.

good luck

[Bowches]

This is my rectifier....

https://postimg.org/image/z7f473acx/

I will have a look at the battery you mentioned.....Now my left indicator is not flashing and a clicking sound is coming...any ideas. I replaced my left handlebar as it was bent. I will take a picture of my steering as it is quite straight now......

[Davez29]

Yes thats a standard Honda shunt (SH) rectifier for your bike, it may last it may not, if it does go try my advise above.

Your flasher relay seems to be clicking, check wiring, connectors, earths and bulbs.

[Bowches]

Thank you Davez29 for the help as always.

My right indicator is working fine, its only the left one. I changed my left handle bar as the previous one was bent. It could of happened when I changed the switch to the new handlebar.

So far the rectifier is working fine....but as my bike is not idling I have to make sure I DO NOT stall. When the engine is switched off that battery goes down quickly if the lights have been on for a while. But if the bike is moving/running then the lights works and the battery actually shows three lights (meaning FULL). There is a button on this lithium ION battery which shows whether the battery is low, medium or FULL indicated by 1, 2 or FULL which is 3 blue lights.

[Davez29]

Im wondering if the wiring is shorting out somewhere. Maybe disconnect the left hand switch to see if things differ. I would also double check your lefthand switch, wiring and connectors. The battery should not quickly discharge with just the ignition on for a couple of minutes, but will if you leave the ignition and lights in the on position without running the engine.
.
You still must check your charging system in anycase, just to discount any problems there.

If this is not the case i would suspect a short. The haynes manual gives a test for discharge problems, sorry i cant remember what it is but the bike should be turned off with the battery connected with the negative lead off when doing the test. Basically its a test showing battery and discharge, wether its the same for lithium i dont know.

Have you got an immobiliser or alarm attached?