dlaing Posted April 24, 2007 Posted April 24, 2007 The breakdown voltage is about 2.39V/cell. i.e. 14.3V So, once all the reactants are converted to their charged state, you MUST turn the current off at about 14V to avoid damaging the battery. Provided the voltage across the cell is less than this, you don't need to worry that much about charging currents within reason. That seems like a low voltage to end the charge at. If Ratchet's intention is not to go over 14.3V with a Sears charger he should watch it carefully....or his Odyssey may die hard Some automotive chargers won't go over voltage you want and some will go well over the voltage that you want. RTFM Be careful and your frugal investment may pay dividends
Guest Nogbad Posted April 24, 2007 Posted April 24, 2007 That seems like a low voltage to end the charge at. If Ratchet's intention is not to go over 14.3V with a Sears charger he should watch it carefully....or his Odyssey may die hard Some automotive chargers won't go over voltage you want and some will go well over the voltage that you want. RTFM Be careful and your frugal investment may pay dividends The monitoring problem arises because when you charge a discharged cell hard, which is ok, the high current means that as well as the cell voltage, you have the voltage needed to overcome the ohmic resistance of the plates, interfaces and electrolyte that could amount to another volt or more across the 6 cells. So, if the battery is consuming a high current during the main charging phase, the voltage may be over 15V quite safely because the actual cell plate to plate voltage that the electrolyte is seeing is still less than 2.39. Once full charge is approached though, the current falls rapidly, and if you are watching the ammeter you will see this happen quite quickly over a minute or two. At that point, you want to stop the thing going much over 14V because the low current means now that the charger voltage is a much better reflection of the chemical state of the cells. The sophisticated electronic battery chargers do this for you by monitoring the current / voltage characteristic and looking for this rapid change in current, at which point they switch to the "float" voltage which is just enough to prevent self discharge. If you are the sort of person who puts their battery on charge and then goes out to a nightclub / brothel etc., you would be better with the fancy charger. If on the other hand you prefer to sit with a glass of scotch reading and occasionally glancing up to check your Sears cheapo charger and DMM in the middle of the lounge carpet, buy the cheap one.
luhbo Posted April 24, 2007 Posted April 24, 2007 Murphy stands against those cheap car chargers. You can count on that. I'm using my R/C all type microcontrolled charger. This won't help you, but I've tried the cheap version before and everytime I wasn't there when it went over 15V. This charger starts with 5,5 A and keeps it until the voltage reaches 14.5. Then it slightly decreases amperage down to 50 mV, this way keeping the voltage all the time at 14.5V. Besides that Hawker claims that 14.7 or even 15V would be better for the battery. Hubert
quazi-moto Posted April 24, 2007 Posted April 24, 2007 This is straying from the thread, but what's a My15M-MKII? Cliff just sent me a new map for (my) My15M and the bike is running excellent! I'm not even running closed loop.
JoeV11 Posted April 25, 2007 Posted April 25, 2007 My BMW riding buddy just bought a charger made for AGM batteries from Wally World for about $60. There was a cheaper one too, but that was 12A vs 14A. Anybody else use that charger? I'm not usually a Wally World customer but would make a special trip if it was worthwhile. Thanks, Joe
luhbo Posted April 25, 2007 Posted April 25, 2007 This is straying from the thread, but what's a My15M-MKII? ... Nothing special, just a Mk2. I still have the first version running, without probs. Once I had water got in and after that it behaved a bit strange. Drying it thorougly and after that some electronics laquer cured it. Anyway I had the MKII already ordered and ready assembled. The major difference between Mk1 and 2 might be the possibility to add a second lambda probe, but here Cliff probably knows more. As soon as I'll have a matching Optimiser I'll give the Mk2 a try, although I don't expect it to behave very much different. Enjoy your My15M Hubert
Alex-Corsa Posted April 25, 2007 Posted April 25, 2007 That looks like a good choice. It seems to meet all of Hawkers specifications. Except for the Deep Cycling requirement of 13A. US 3300 seems to be US model http://www.ctek.com/us/MUS3300/features_benefits.asp I use this one and it is fully automatic. It self adusts to the battery needs and when it is fully recharged no problem if it is left on (it switches off alone).In fact as it says in it's manual you can leave it on for days with no problem. have read some of the best reviews in the press and as long as I have used it (2-3 times) it worked flawless. I would recomend it.
Steve G. Posted April 26, 2007 Posted April 26, 2007 I use this one and it is fully automatic. It self adusts to the battery needs and when it is fully recharged no problem if it is left on (it switches off alone).In fact as it says in it's manual you can leave it on for days with no problem. have read some of the best reviews in the press and as long as I have used it (2-3 times) it worked flawless. I would recomend it. I've got my Odyssey owners manual right here in front of me. I sais right here "do not use trickle charger or battery tender devise". Do not charge it. I think you've #@$&@#@ it. The battery in my V11 has been slumbering for 6 months. I pressed the starter last weekend, it started immediately! DO NOT CHARGE THESE THINGS! Ciao, Steve
Guest Nogbad Posted April 26, 2007 Posted April 26, 2007 I've got my Odyssey owners manual right here in front of me. I sais right here "do not use trickle charger or battery tender devise". Do not charge it. I think you've #@$&@#@ it. The battery in my V11 has been slumbering for 6 months. I pressed the starter last weekend, it started immediately! DO NOT CHARGE THESE THINGS! Ciao, Steve I think they are very sensitive to overcharging because of the small electrolyte inventory. My battery always used to start the bike even after long time standing until I put Gerbing gloves on it and rode in the winter in urban traffic. I guess there just wasn't enough power at the average rpm I was using. Anyway, I think you will be fine charging it fairly hard for a short time, and then taking it off charge immediately the charging current is seen to fall. After all, the bike's alternator probably replenishes the charge used for the cranking session in a few minutes at a charge rate of 15 to 20A!
mdude Posted April 26, 2007 Posted April 26, 2007 I'd like to put in a world for the CTEK chargers. I've owned one for a couple of years. Smart bugger, it handled the advanced (and horribly expensive) gel battery on my former BMW 1150, the huge oldstyle car battery in my Audi 4WD roadracer and both batteries in our bikes this winter. No fuzz, full charge, and it takes care of itself after hooked up. Its also quite cheap AND very compact. Best of all worlds, innit?! With the charger comes a fast connect plug which, when attached to the batt. poles, allows you to connect the charger without fumbling around on the battery itself. Even my wife can deal with that.
Guest Nogbad Posted April 26, 2007 Posted April 26, 2007 Even my wife can deal with that. Does she read this forum?
guzzijack Posted April 26, 2007 Posted April 26, 2007 Does she read this forum? He better hope not! GJ
rossoandy Posted April 29, 2007 Posted April 29, 2007 so wat we saying here is..DO NOT use an Optimate or similar batery tender with a Hawker Siddely battery? I've often hooked mine up when bike unused for periods and battery seems fine...
Guest Nogbad Posted April 29, 2007 Posted April 29, 2007 so wat we saying here is..DO NOT use an Optimate or similar batery tender with a Hawker Siddely battery? I've often hooked mine up when bike unused for periods and battery seems fine... Prolly be fine if the float voltage is low enough. Anyway, I guess you will get through several engines per battery so I wouldn't worry.
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