Do I need a new battery?

[Kalessin]

I had thought this was a no-brainer, but I've had various conflicting advice so I thought I'd throw it open to the floor

My K5 had 3,250 on the clock when I bought it. With the exception of snow days, I've done at least 15 miles per day. I had assumed this would keep the battery charged.

Last night when I left work, the starter seemed to struggle before the engine caught.

This lunchtime, 17 hours later, it refused to turn over more than about twice

I have had battery issues before if I've left the ignition on for too long (5 mins) before starting the engine, if I've been distracted, but I've left the bike alone for 20 minutes and it's started no problem.

Some people I have spoken to have said that 15 miles per day is not enough to keep the battery charged and I should trickle charge it this weekend and it'll be fine.

Others have said that as the bike only had 3k miles in the first 4 years of its life, the battery may have deteriorated and need replacing.

As it's my sole method of transport, I don't want to be stuck with no way to get to work, so if you think I need to get a new battery, I'd rather just get it done (and then charge it over the weekend, obviously).

[Sid Squid]

It certainly sounds like the battery, but I'd do charging system and battery leak tests, if both of those check out OK then that confirms the battery is suspect.

I thought mine was the battery recently and it turned out to be something else (very similar symptoms to yours). I'd do as Sid suggests and get the battery tested before replacing it...

i'd buy a new battery, and keep your old one trickle charging and then see.

[timwilky]

Originally Posted by shonadoll

i'd buy a new battery, and keep your old one trickle charging and then see.

Why, it is a bit like going to the docs and saying I don't feel well and he suggests I will book you in for a liver transplant.


without doing basic fault finding it could be one of many problems

easiest poor battery connections or other wiring fault
next easiest knackered RR
knackered battery
knackered alternator

Do not go out and buy a battery, go out and buy a multimeter

Originally Posted by timwilky

Why, it is a bit like going to the docs and saying I don't feel well and he suggests I will book you in for a liver transplant.


without doing basic fault finding it could be one of many problems

easiest poor battery connections or other wiring fault
next easiest knackered RR
knackered battery
knackered alternator

Do not go out and buy a battery, go out and buy a multimeter

Because if it is the battery, in the meantime he's not stuck without transport?

[timwilky]

Originally Posted by shonadoll

Because if it is the battery, in the meantime he's not stuck without transport?

and if it was not the battery he then gets stuck in the middle of nowhere with no lights, not running, possibly writing off new battery by cooking it etc.

Do a check of the charging system first with a £5 multimeter before spending £50+ on a battery.

Measure the voltage across the battery 30 mins after a charge

measure it again with the engine running at about 5000 rpm and lights on

the above is sufficient to tell us if the charging system is working or not.

I would expect to see something about 13 - 14V.

If not. disconnect the 3 yellow wires going into your RR

think of them as a,b,c. Turn your multimeter onto the ac voltage scale and measure the voltage between ab, ac, and bc. you should be seeing something about 70-90v. from the alternator

if the alternator reads ok and you are not getting the charge to the battery it is a goosed RR. Go out and buy a nice one from a Honda. muller the connections to fit. or source a reputable pattern part.


If the initial check was ok and you were getting the 13-14v. Leave the bike overnight and measure the voltages again in the morning.

Batteries do age over time and 4 -5 year is their norm. They do not perform well in the cold and twins like the SV require a heavier cranking current. So one tip I should have said make sure you have the correct battery installed. It is not unknown for a previous owner to have replaced a goosed battery with a cheaper alternative

[Kalessin]

Many thanks for your responses. Extra special thanks to timwilky who answered the question I was too embarrassed to ask: "What are you going on about?"

So, I borrowed a multimeter (sorry, a "Digital Automotive Analyser") from work and I'm going to borrow a battery charger from a mate. I know I should buy one, but everywhere will be shut by the time I leave work. I don't know if it'll fit because the battery terminals seem quite recessed and crocodile clips on car battery chargers are quite bulky. That's why I couldn't jump start it earlier (that and the fact that I didn't want to be stuck at work later).

If the charger fits, I'll leave it trickling overnight and take some measurements in the morning.

Thanks again!

if you got breakdown cover, call them out and get them to jump start it if you got a problem and are desperate.

And 15 miles each way should be enough to fully recharge the battery,

[Kalessin]

Originally Posted by thefallenangel

if you got breakdown cover, call them out and get them to jump start it if you got a problem and are desperate.

And 15 miles each way should be enough to fully recharge the battery,

I would call them out if I thought they'd bring me a new battery! But as it's just tacked onto my insurance, I think there's a limit to the number of times I can call them out.

It's 7-ish miles each way, 15 total. Do you think that's the problem?