Hi everyone, I am buying a new battery for my Bonneville T100, 2003, 790cc carb model. On many websites (I'll use Bosch as an example) I get two options: 1) Bosch YT12B-BS, Capacity 12AH, Cold start 190A (recommended for 2009 onwards) 2) Bosch YTX12-BS, Capacity 10AH, Cold start 90A I am a complete electrical novice and do not understand the differences. Could someone explain in layman's terms what this actually means. Perhaps the first one mentioned above is overkill for an older machine, but is there any actual disadvantage to it? i.e. could I damage something by using a stronger battery? I struggle with my batteries only lasting one summer and I am sick to death of buying a new one every year. Any advice you could share would be very much appreciated! Cheers, Ben
Hi Ben, I always go for the very best battery I can on all my vehicles. You can't hurt the bike going for the higher spec version, there's no downside so go big !!!
The "YT" reference you give for the Bosch batteries is simply the manufacturers mark. YTX12 - BS indicates that it is a maintenance free battery and the "X" shows that it is a high performance one. 12 is the indication of performance level of the battery (12 being fine for a bike). B is the type of terminal and S means it's sealed. The AH designation stands for "Amp hour" - an indication of how much energy can be stored by the battery. The cold start 190A is a measurement of the discharge load in amperes that a new, fully-charged battery can deliver for 30 seconds, while still maintaining terminal voltage equal to or higher than 1.20 volts per cell.
I'll probably just add to your confusion, but you also have different choices of battery types (how they are made - not the manufacturer). The attached is a pretty good description from BikeMaster of their line of batteries. https://img.jpcycles.com/staticwebfiles/instructions/pdf/ZZ36009.pdf
If your batteries are only lasting 1 year something else is going on. You should easily get 4+ years out of a battery if there are no bike electrical charging issues and if the battery is properly maintained. Have the bike charging system checked out and use a maintenance charger when the bike is not in use. Any battery will slowly be damaged over time if it gets discharged. And any battery slowly discharges just sitting there which is totally normal. I use a Battery Tender Junior and always have it plugged in when my bike is not in use. My batteries have always gone many years. And if your bike's charging system is not working properly, 9 times out of 10 it is a bad voltage regulator.
Electrics in layman’s terms? You need a 12v battery that fits the battery box! Think of 12v as the speed of the river flow. You need sufficient amps to do the work. The toughest thing a battery does is crank the engine over. Think of amps as the volume of water flowing......so the difference between a stream and a river both flowing at 12v. The two key amperage measurement are (as above) Amp Hours - total battery storage capacity and CCA or Cold Cranking Amps which is immediate starting muscle. You pays your money and makes your choice but the single biggest determinant of battery longevity on an occasional use vehicle is more likely the use of a smart charger than the battery type or brand itself. Something like a 4amp Ring charger from Toolstation for £35 will pay for itself in battery life and surefire year round starting. Insert your reg no and decide on your budget...... https://www.mdsbattery.co.uk/yuasa_12v.html Likewise a £10 multimeter across the battery terminals of a running engine will tell you if your charging system is working. A blipped throttle should get nearly 14v.
Battery option 1 is for the later electronic everything, fuel injection ! Bike reqires extra amperes to run everything, the 2nd is for the earlier carb'd bikes, which dont carry the electronic loads that the later models do , as it only runs the ignition and lighting !!
Wow thanks guys that is really informative. I have got myself a battery from a friend of mine who runs a car garage, he is a Bosch supplier, I got it from him under the proviso that should it stop working like the Banner batteries etc. that I have had in the past then he will send it back as defect and replace it for another one. I have two "smart chargers" one is from CTEK and the other is a Saito Pro-Charger. The CTEK one cost about EUR 70.00 or maybe a bit more and can be setup for car or bike and winter mode (I presume trickle). It was once suggested to me that this charger could be a problem given that it only tops up the battery which in the long run is apparently not good for it. I think from memory it is this one: https://www.ctek.com/products/vehicle/mxs-3-8 So, I bought the second one, a Saito Pro-Charger which cost less at EUR 50.00. This one tests the battery, performs desulfurisation and discharges the battery (as well as chargers it) so the level of charge goes down and then back up again instead of always being topped up and up. Info is here: https://www.getgeared.co.uk/core/media/media.nl?id=7268&c=731612&h=e439f1f2a97b5c9c46f1 So, am I right in thinking that in winter I disconnect the battery, bring it in the house where it is not so cold and once a month plug it in to this Pro-Charger device for a couple of days. Then come spring when the snow has melted it should be good to go? Should I be doing anything else? Or more often? I will definitely do the multimeter test to see what numbers I get with a twist of the throttle. If it turns out to be something like the voltage regulator, how can I test for this? Thanks again everyone, your help and advice is very much appreciated!
Leave it on the bike - a charged battery will not freeze in the garage - and leave the smart charger permanently hooked up. It consumes negligible power but detects changes in the battery and reacts. It is the kindest treatment you can give a battery. Bringing the battery inside is not worth the likely grief!
So I put a couple of km's on the clock, literally about 5 or 6, with the new battery. Work, weather, family etc. getting in the way for anymore. Then I did the multimeter test and I got 12.3V with the ignition off and 13.4V +/- with the ignition on and the choke open. So far so good. I am waiting to see how it fairs over the next few days, it is currently plugged back into the ProCharger as I am working all day, all week and have zero time for riding at all. Not ideal I know with a new battery, but I'm hoping the charger can maintain it in the meantime. Thanks again for all your help. If I continue to have charging problems I will have another look into the regulator/rectifier. If anyone has any ideas on how to test, and where to buy a replacement, or upgrade, please let me know! Cheers, Ben
Your numbers may be a little low. Typically, a new battery should be ~12.6 volts to ~12.8 volts, and with the engine running around 2,000 rpm, the test at the battery terminals should show ~14.5 volts. If you were running the engine at ~2,000 rpm, your voltage would indicate a bad alternator, but you need to run other tests to be sure. I have three Triumph Shop Service Manuals for different models. They all have a diagnosis page in Section 1 that will walk you through the checks to tell if it is a battery, rectifier/regulator, or alternator. Each of mine appear to be the same procedure, but they are for 2012, 2013 and 2014 models. You may want to find someone with the Service Manual for your year/model and get the correct test procedure.
You have done the right thing. It is a mistake to assume a ‘new’ battery that may have been in storage for months is fully charged - that may explain your marginally low numbers. The smart charger will have a display indicating the amperage rate at which it is charging until it shows ‘full’. That alone tells you it is not fully charged.
That is a good idea. I have 2003 Bonneville T100, its done quite a few miles so I would expect to have to replace the odd bit here and there. So does anyone have the correct manual so I can follow the proper test procedure to see if I need to replace my alternator or regulator etc. Thanks, Ben
