Battery Issue

[redeem ouzzer]

Hi A/all.

In my YR5 project bike https://www.bikechatforums.com/viewtopic.php?t=315359 i'm using a 1.2 ah battery to save space and weight.

https://i.imgur.com/H4w4uki.jpg

I did about 40 miles of thrashing tonight in order to get a feel for the engine after the dyno set up. Coming back home the bike cut out at the top of the street, having ran out of electricity. Multimeter showed 5v, not good. I put the battery on charge but it wasn't really willing to take much charge, however i got 12v into it and the bike showed signs of life. Got it fired up and it seems the charging system is fine (lights going bright, 13.9v across pos / neg which is the rated maximum of the regulator). Then all of a sudden it pigged again, battery flat must be under 7 volts to stop the CDI firing so it seems the voltage has bottomed out again.

I'm thinking knackered battery but i'm not sure exactly how it's gone from fine to this in the space of one ride

I get the recovery light on my optimate when i try to charge it.
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Be a REAL MAN!

[doggone]

I'd suspect a bad earth, while it's in the poorly state connect a jump lead from black to bright metal somewhere.

[redeem ouzzer]

[Islander]

Batteries can fail suddenly - it happened to me on my GSF1200 recently. It had been running, i washed the bike went to start it, it turned over and started then cut out and wouldn't even turn over again. Cause? Internal high resistance. New battery sorted it.

[Kawasaki Jimbo]

12V, but 1.2 Ah! I'd say you're starting a bike with a torch battery, sucking its guts out and then expecting the charging system to resuscitate it. Not good.

[jaffa90]

This is a wind up, i`ve just bought one of these batteries for the house alarm battery back up when power fails.

[Polarbear]

I doubt that battery can handle the amount of power you are shoving through it in normal running. You are just killing it.

Read this..............

It is reasonable, though, to consider the maximum current a battery can safely deliver. That value will depend on all kinds of things, including the chemistry of the battery, but the maximum discharge rate is almost always tied to the capacity. That means that given a particular technology, a battery with double the capacity can deliver double the maximum current. Batteries are often specified with a discharge rate in terms of C, where C is the capacity of the battery divided by hours. For example, for a 2Ah battery, C is 2A. If the battery has a maximum discharge rate of 10C, the maximum current is 20 amps. It’s good to keep in mind that a 10C discharge rate means a battery life of less than 1/10th of an hour, and with the loss of capacity that a high discharge rate generally causes, the battery life would be less than five minutes.
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Triumph Trophy Launch Edition

[ThatDippyTwat]

Tiny battery, big (in relative terms) charge. You are on the way to doing this...

https://www.zbattery.com/Overcharging-SLA-Batteries

You need a bigger battery, or a way to dump a significant portion of your stator's output. A bigger battery is a metric fuckton easier, and cooler than a bank of power resistors, which is the simple way to create a dummy load and "suck up" some of that output.
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'98 VFR800 (touring) - '12 VFR800 Crosrunner (Commuting) - '01 KDX220 (Big Green Antisocial Machine)

[redeem ouzzer]

[ThatDippyTwat]

It's not the voltage, it's the current that's the problem.

EDIT:-
You may want to look into a 3s LiPo and a BMS, which will be smaller and lighter than a Pb cell. However, be aware that if you overcurrent a Lithium cell during a charge, even the "safe" formulations such as LiFePO4, they react badly and explosively.

LiPo is Lithium Polymer, it comes in a wide range sizes. You can build cells up to best use the space available. BMS is Battery management system, a PCB you'll need to put on a pack. You need a BMS with a decently wide input voltage. Something designed for the output of a car ("mobile") is perfect.
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'98 VFR800 (touring) - '12 VFR800 Crosrunner (Commuting) - '01 KDX220 (Big Green Antisocial Machine)

[Johnnythefox]

how many tonnes weight did you save compared to the OEM battery?

[Tankie]

This is not an automotive quality battery it is not designed to handle vibration.
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Always learning, everyday is a school day

[redeem ouzzer]

[jjdugen]

Lipo batteries are the equivalent of owning a Ducati, lots of power but with a propensity to go BOOM! I use Li metal Hydride batteries if space is restricted. Almost the same energy content as Lipo, far less fussy about charge rates, safe for the environment too. Dunno why they are always overlooked.
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The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[Johnnythefox]

[redeem ouzzer]

[jjdugen]

https://data.energizer.com/pdfs/nickelmetalhydride_appman.pdf
https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery

I used these on a sixties Honda I had to re-engineer the (not) charging electrics. To get a bit Teff on you. Back then, there were no regulators, the rectifiers were plates of Selenium stacked up on top of each other. Because there was no regulation, the alternator output was designed to only peak at around max RPM, running around town at lower revs, with lights on, use of brake lights, soon began to flatten the battery. A modern reg/rec helped, but I had to re-wind the stator to give a higher output. Even so, the battery was tiny, Like you, space was very restricted. One use of the electric starter and the lead acid battery was severely drained.
I put in a bank of metal hydrides and cranking capacity was as good as a modern system.
The only mod that I incorporated was a thermal resistor clamped to the battery cells in the charging line from the reg/rec. As these batteries reach full charge, they heat up, the thermal resistor acting to reduce the incoming voltage supply. I did have to do some research, it was on a long defunct lap top so I'd have to start racking my brains again for full details.
Hope this helps.
Cheers.
____________________
The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[ThatDippyTwat]

[jjdugen]

Yeah, Typo....
These are used in air sampling pump units I have a small service contract to repair, (therefore I have 'access' to them for experimentation / evaluation....you understand....). So. In use I have found them to be very robust, even with constant deep discharge cycles and erratic charging regimes. I agree, no argument, that for ultimate capacity, with the state of battery technology, Lipo gives best energy / weight / size combination. Its just too touchy for my liking in the raw charging environment of a motorcycle.
Pays your money, takes your choice I suppose, its just an alternative I'm throwing out there....

Cheers.
____________________
The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[lingeringstin...]

OK I'll put in my two pence worth.

I used batteries almost exactly like that for YEARS on my MZ without any problem whatsoever. They were generally house alarm batteries that were given to me for free because they were "dead".

I had changed to a BMW style electronic voltage regulator (Lucas NCB403, now obsolete but there are replacements) but everything else was still standard MZ field coil alternator and MZ rectifier. Kick start only and very few lights.

I only ever had one battery go dead on me and it did it suddenly and without warning. It was working perfectly fine and then one day it just stopped without the slightest hint of a volt in it. I assumed something had come loose inside because it wasn't low, it was totally zero volts dead. But all the others worked flawlessly for like 20 years of riding, sometimes on a daily basis as a courier.

I didn't have to buy a new battery for many years until I changed jobs and no longer had a source of free batteries, and even then I just started using two of those little Maplins 6v sealed batteries, which claim something like 4ah, wired together for 12v because they used to have them on sale at half price (about £6) every December so every few years I'd just buy a couple more to be on the safe side.

Everybody, including people with a lot more understanding of electric shit than me, said it'll never work but it always worked fine.

I know very little about the science of batteries and charging systems but what I do know is that what you're trying to do worked perfectly fine for me on a kick start bike with low electrical needs.

[ThatDippyTwat]

[redeem ouzzer]

[jjdugen]

3a Technology Ltd
Address: 27ab Vernon Mill, 3rd Floor, Mersey St, Stockport SK1 2HX, United Kingdom
Just for ThatDippyTwat..... These are my suppliers. They make up cell packs to order, sealed and with a pair of flying leads. Quite reasonable prices.

Cheers
____________________
The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?