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Post by Deleted on Jan 14, 2020 17:26:09 GMT
I checked the reading with a hydrometer this morning before turning on any power, the reading was between 1.250 and 1.270. I've not checked after a full charge yet. If all the cells are in that range, it seems odd that the batteries are that bad. How are you determining that they are down to 1/2 capacity? Maybe you should try discharging them down to 20% SoC or so (11.7v no load voltage) and then recharge. Our batteries held up well using AH counter vs Smartgauge, until getting down to the usual morning state of around 65 to 70%. On the few occasions that I discharged them further, the voltage (and hence the Smartgauge reading) dropped rapidly. Eventually I did a pretty major discharge to 20% and slowish recharge at 50A or so, now they are much better. I think they can get a bit lazy always cycling over the same fairly small range. If that fails, you could try beating them with a branch in the style of Basil Fawlty. Well, I followed your instructions on depleting the batteries, then hammering with the charger. It has made a difference that could be described as quite substantial, so thankyou very much for the advice. I did consider bashing them with a twig, thinking along the lines of it would stir up the acid, but the charge seems to have improved things quite a bit, so thanks again. 😊
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Post by Deleted on Jan 14, 2020 17:26:16 GMT
I've got a few little AGM batteries 7ah up to 24ah. The 7ah one didn't want to get back into use after going totally flat. I don't know whether they would recover. Might be scrap I reckon .
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Post by Deleted on Jan 14, 2020 17:33:27 GMT
So anyway I once knew this old codger with severe Parkinsons. Sadly he has now passed. But one time we were waffling about boats, and I mentioned I was toying with the notion of setting up some kind of battery bank in order to be able to re-charge hand-held units while on an extended cruise (vhf, tablet, mobile, gps). So he gave me some batts intended for a scooter. I assume that they were past their best because they were clearly not new. I put them away in a cupboard and like a lot of things never got round to experimenting with that idea. That was about five years ago. But all this talk about charging and whatnot piqued my interest. On closer inspection, they are 12v AGM items. I connected my trusty multimeter which revealed...about 0.5 of a volt...not good. So I have hooked one up to my trusty very cheap charger which seems to be delivering about 3 amps. I will leave it on charge till the morning. The batt is getting a tad warm but so far its at about a 25 minute old cup of tea so I'm not concerned. So how likely is it that they will hold a charge? How long is a suitable test-period once the batt is a fully charged as I can make it? Answers on the back of a ten pound note. batteryuniversity.com/learn/article/absorbent_glass_mat_agmI've found this quite a good web site Re : Batteries. Long term storage of depleted AGM batteries doesn't bode well but it's good to experiment as well as believing theory. I lost a good friend to Parkinsons (on Christmas day apparently). He was a great car mechanic and taught me a lot. Such a crap disease... :-(
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Post by Deleted on Jan 14, 2020 17:33:29 GMT
I've got a few little AGM batteries 7ah up to 24ah. The 7ah one didn't want to get back into use after going totally flat. I don't know whether they would recover. Might be scrap I reckon . When you say 'didn't want to get back into use' do you mean it refused to accept a charge or it didn't hold one?
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Post by Deleted on Jan 14, 2020 17:37:02 GMT
So anyway I once knew this old codger with severe Parkinsons. Sadly he has now passed. But one time we were waffling about boats, and I mentioned I was toying with the notion of setting up some kind of battery bank in order to be able to re-charge hand-held units while on an extended cruise (vhf, tablet, mobile, gps). So he gave me some batts intended for a scooter. I assume that they were past their best because they were clearly not new. I put them away in a cupboard and like a lot of things never got round to experimenting with that idea. That was about five years ago. But all this talk about charging and whatnot piqued my interest. On closer inspection, they are 12v AGM items. I connected my trusty multimeter which revealed...about 0.5 of a volt...not good. So I have hooked one up to my trusty very cheap charger which seems to be delivering about 3 amps. I will leave it on charge till the morning. The batt is getting a tad warm but so far its at about a 25 minute old cup of tea so I'm not concerned. So how likely is it that they will hold a charge? How long is a suitable test-period once the batt is a fully charged as I can make it? Answers on the back of a ten pound note. batteryuniversity.com/learn/article/absorbent_glass_mat_agmI've found this quite a good web site Re : Batteries. Long term storage of depleted AGM batteries doesn't bode well but it's good to experiment as well as believing theory. I lost a good friend to Parkinsons (on Christmas day apparently). He was a great car mechanic and taught me a lot. Such a crap disease... :-( Sure is but then I can't think of a good one. His mind was sharp; his body was a useless wreck. I have heard of people living with Parkinson's and dementia. Imagine that. As far as the batts go its a total experiment. The only potential grief will be 'ethically' disposing of them if they are junk.
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Post by Deleted on Jan 14, 2020 17:41:08 GMT
I've got a few little AGM batteries 7ah up to 24ah. The 7ah one didn't want to get back into use after going totally flat. I don't know whether they would recover. Might be scrap I reckon . When you say 'didn't want to get back into use' do you mean it refused to accept a charge or it didn't hold one? It got warm but did not charge up.
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Post by Deleted on Jan 14, 2020 17:45:33 GMT
When you say 'didn't want to get back into use' do you mean it refused to accept a charge or it didn't hold one? It got warm but did not charge up. Righto. Just checked mine and the temperature has gone up! I'll leave it a bit longer then put another one on charge for comparison (I have four of the damn things). ETA not that its terribly exciting but after about six hours charge and immediately after taking it off the charger I had a reading of 11.9 volts which is better than 0.5... I'll try it again in an hour or so. I'm tempted to buy one of the Chinese chargers advertised on ebay for little cash that claim to have a 'pulse repair mode' at very low amps. Anybody ever tried one?
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Post by Telemachus on Jan 14, 2020 18:23:56 GMT
Yes there are drop in replacements by the likes of Victron and Mastervolt, but very very expensive. And certainly the early version had problems with premature death. IMO if you want to switch to lithiums, you really need the charging and monitoring systems adapted for that specific purpose. Thanks Nick. Yes, I suppose it’s not very cost effective paying for a built in controller inside the battery if the battery is going to fail early. I reckon 50-60ah will do me if I splash out on a lithium battery. The only other requirement for me is that it can cope with dishing out up to 300 watts for short intervals (2-3 minutes). What would be the minimum I’d need to control the charging from the alternator? I can’t reaiiy justify paying too much if I’m getting away with a £70 starter battery every year... There isn’t an easy answer, it is a complex subject. But for a quick and dirty solution my best suggestion would be to fit a lower voltage alternator regulator to your alternator, set to 13.8v - 14v. If you don’t go over 13.8v the risk of overcharging is kept low. But you do need some means of balancing the cells. There are two types of battery, one being a set of 4 separate bare cells to be DIY wired in series. The other is a “battery” internally comprising the 4 (or more) cells with some sort of battery management system built in, which may be able to do cell balancing. If you choose bare cells, you really need to add a BMS or at least a means to balance the cells. One problem with internal BMS is that the electronic protection switches present a limitation in terms of maximum current in or out. You might be struggling to get 300w out of a 50AH battery. The cells can easily provide that current, but the electronics may not be able to cope with it.
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Post by peterboat on Jan 14, 2020 18:36:54 GMT
Thanks Nick. Yes, I suppose it’s not very cost effective paying for a built in controller inside the battery if the battery is going to fail early. I reckon 50-60ah will do me if I splash out on a lithium battery. The only other requirement for me is that it can cope with dishing out up to 300 watts for short intervals (2-3 minutes). What would be the minimum I’d need to control the charging from the alternator? I can’t reaiiy justify paying too much if I’m getting away with a £70 starter battery every year... There isn’t an easy answer, it is a complex subject. But for a quick and dirty solution my best suggestion would be to fit a lower voltage alternator regulator to your alternator, set to 13.8v - 14v. If you don’t go over 13.8v the risk of overcharging is kept low. But you do need some means of balancing the cells. There are two types of battery, one being a set of 4 separate bare cells to be DIY wired in series. The other is a “battery” internally comprising the 4 (or more) cells with some sort of battery management system built in, which may be able to do cell balancing. If you choose bare cells, you really need to add a BMS or at least a means to balance the cells. One problem with internal BMS is that the electronic protection switches present a limitation in terms of maximum current in or out. You might be struggling to get 300w out of a 50AH battery. The cells can easily provide that current, but the electronics may not be able to cope with it. My valences can, hence I have a vaporised 13 mm deep socket wiped it out totally nothing left of one end of it
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Post by Deleted on Jan 14, 2020 19:48:49 GMT
There isn’t an easy answer, it is a complex subject. But for a quick and dirty solution my best suggestion would be to fit a lower voltage alternator regulator to your alternator, set to 13.8v - 14v. If you don’t go over 13.8v the risk of overcharging is kept low. But you do need some means of balancing the cells. There are two types of battery, one being a set of 4 separate bare cells to be DIY wired in series. The other is a “battery” internally comprising the 4 (or more) cells with some sort of battery management system built in, which may be able to do cell balancing. If you choose bare cells, you really need to add a BMS or at least a means to balance the cells. One problem with internal BMS is that the electronic protection switches present a limitation in terms of maximum current in or out. You might be struggling to get 300w out of a 50AH battery. The cells can easily provide that current, but the electronics may not be able to cope with it. My valences can, hence I have a vaporised 13 mm deep socket wiped it out totally nothing left of one end of it Don't worry, I'm sticking at £70 per year for now until Tesla gets justice ;-) Now...who killed Tesla?
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Post by Telemachus on Jan 14, 2020 19:55:15 GMT
There isn’t an easy answer, it is a complex subject. But for a quick and dirty solution my best suggestion would be to fit a lower voltage alternator regulator to your alternator, set to 13.8v - 14v. If you don’t go over 13.8v the risk of overcharging is kept low. But you do need some means of balancing the cells. There are two types of battery, one being a set of 4 separate bare cells to be DIY wired in series. The other is a “battery” internally comprising the 4 (or more) cells with some sort of battery management system built in, which may be able to do cell balancing. If you choose bare cells, you really need to add a BMS or at least a means to balance the cells. One problem with internal BMS is that the electronic protection switches present a limitation in terms of maximum current in or out. You might be struggling to get 300w out of a 50AH battery. The cells can easily provide that current, but the electronics may not be able to cope with it. My valences can, hence I have a vaporised 13 mm deep socket wiped it out totally nothing left of one end of it Yes but they don’t have a “proper” BMS with a built in means to protect the battery from over or under charge by isolating it. Yours are a bit of a halfway house. It is the means to isolate the battery that presents the discharge current limitation.
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Post by Deleted on Jan 14, 2020 19:58:27 GMT
My valences can, hence I have a vaporised 13 mm deep socket wiped it out totally nothing left of one end of it Don't worry, I'm sticking at £70 per year for now until Tesla gets justice ;-) Now...who killed Tesla? Tesla shares are absolutely flying at the moment. Do you have inside information about a major correction? Stock price has tripled in 7 months.
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Post by Mr Stabby on Jan 14, 2020 19:59:51 GMT
For what it's worth ... many years ago a mate who is a live aboard, purchased leisure batteries at a chandlers. The batteries had a two year warranty, but when he enquired about details he was told that the warranty does not apply to live aboards as all leisure batteries are designed for occasional use, not constant recycling. He then contacted the battery company and was advised that two to three years was the expected life of any leisure battery if in constant use, provided recharging wasn't an issue. The warranty on batteries covers manufacturing faults, sulphation will never be considered to be a warranty claim by any manufacturer.
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Post by Deleted on Jan 14, 2020 20:03:46 GMT
Don't worry, I'm sticking at £70 per year for now until Tesla gets justice ;-) Now...who killed Tesla? Tesla shares are absolutely flying at the moment. Do you have inside information about a major correction? Stock price has tripled in 7 months. Cone on mate.. you know I don't do money...
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Post by Deleted on Jan 14, 2020 20:06:50 GMT
I was just intrigued by someone killing Tesla.
It seems like they are the ones doing the killing currently.
It does appear inevitable that electric cars will become the norm and they do seem to be making some pretty well sorted cars. Electric from the start not a mod of a IC engine car.
I'm not a fan of the brand personally in a similar way I would never buy an Apple product but they do seem to be doing something right.
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