|
Post by GO30 on Jun 6, 2023 15:20:49 GMT 12
Watch out for lead crystal, they are anal when it comes to charging and a mate who deals with them suggests most boats don't have the grunt to recharge them properly. Can't quite remember the fine details but they like being charged at huge amps if you want them to work the best for a long while.
|
|
|
Post by em on Jun 6, 2023 16:47:04 GMT 12
Watch out for lead crystal, they are anal when it comes to charging and a mate who deals with them suggests most boats don't have the grunt to recharge them properly. Can't quite remember the fine details but they like being charged at huge amps if you want them to work the best for a long while. Heard the same from a mate who works for a marine outfit that deals with them . They sold them at 1/2 price to move them and have had headaches getting them to work
|
|
|
Post by Fogg on Jun 6, 2023 19:25:38 GMT 12
Fish, give Matt a call / text and ask him to advise you on the big ticket options. Then next step would be to meet him aboard to do a proper assessment and $ cost estimate.
|
|
|
Post by fish on Jun 6, 2023 21:02:15 GMT 12
Watch out for lead crystal, they are anal when it comes to charging and a mate who deals with them suggests most boats don't have the grunt to recharge them properly. Can't quite remember the fine details but they like being charged at huge amps if you want them to work the best for a long while. I'm talking lead carbon (Pb-C), not lead crystal. They are basically an AGM battery, fairly straight forward lead acid technology. The only difference is the negative plate is coated and / or made up of carbon. This means it can't sulphate (or substantially improved sulfation resistance). That means you can sit them at partial states of charge without risking sulphation as in a standard AGM or lead acid battery. So on a boat, if the engine is off cause I'm actually sailing, and the solar isn't working, cause its like an Auckland summer, the batts won't get buggered in the same way my current batts are buggered. Additionally, the carbon negative plate reduces resistance, so they can be charged at good high amperages. Where I was getting 10 or 20 amps into my LA Batts, I should be able to get 40 or 50 amps into these new ones. I have a 75 amp alternator. Noting that there is still a tail current to get it to 100% SOC. What I haven't got my head around, is they say these negative plates also act like super capacitors. This means the battery can put out super high current if you want it to. I def don't want it to. But in off grid applications, if you want to boil a kettle or run a microwave for 3 mins, these batts will feed an inverter with as many amps as you want. Like 1C or 2C. So a 250 Ah batt can give you 500 amps to boil the kettle if you want. Incase you run out of gas?! The batt tech seems well established in the off-grid market. Nerada is a big brand there. And Jim has some. Spoke two suppliers today. Sounds like I can do a straight swap. No mention of any issues like you mention with lead crystal. Need to check / update the charging parameters on the smart regulator and the solar, but no new equipment requirements. I am still working through all the technical aspects. At the moment the only benefit I can see from lithium is I get linear current uptake during charging until full. The Pb-C will have a tail current, which I am in the process of investigating and understanding. Giving I can get 250Ah for $750, they can go down to 80%DOD (intermittently) and they tolerate Partial SOC, I don't see a need to try and get the last few amp hours into them to get to 100%SOC. I will supplement the alternator with solar, so on a good day that will get the batts to 100% SOC. Basically lead carbon gives me 200 Ah of usable capacity for $750, while lithium will give me 200 Ah for about $1,800 minimum. I think it is a no-brainer. Just working through all the techo details and will get some professional advice before I pull the trigger.
|
|
|
Post by harrytom on Jun 6, 2023 23:13:49 GMT 12
"Fish" if you charge your old batteries at home and hold a charge for say 7 days.Then that would suggest not a battery issue. So no matter what batteries you install your problem will still be there,a discharge/stray current onboard. Dumb question but do clean the top of the batteries regularly as salt build up can create a circuit.
|
|
|
Post by fish on Jun 7, 2023 9:16:47 GMT 12
"Fish" if you charge your old batteries at home and hold a charge for say 7 days.Then that would suggest not a battery issue. So no matter what batteries you install your problem will still be there,a discharge/stray current onboard. Dumb question but do clean the top of the batteries regularly as salt build up can create a circuit. We are running that test. It is still early days. So far: Sunday 8pm 12.82v (several readings before that, but basically the surface charge coming off, dropping from 13.05v to 12.82 over 7 hours) Monday 1pm 12.77v Tuesday 11:30 am 12.74v
I probably need to be patient and wait 7 days to get a good indication of how they are holding charge. My understanding is 1v is 100% of capacity (or near enough). Fully charged 12.8v, 50% 12.3v and 0% 11.8v. So every 0.1v drop is 10% of the capacity. Once I have enough data points I will plot it and calculate the rate of self-discharge. But if it has dropped to 12.3 after 7 days, the answer will be clear enough. Today's number will be most interesting, as it will be well clear of the time taken for the battery to stabilise post charging, and the surface charge to come off.
We are also getting organised to do a full equilisation charge to see if we can reserect them at all. Need to monitor them and what not while that is going on. My father's trailer home has suitable mains powered chargers to give them the full ergs for a good jiggle up.
|
|
|
Post by fish on Jun 8, 2023 9:37:14 GMT 12
So far I can say looking for and trying to select new batteries is like going down a rabbit hole.
All of the Pb-C brands on the market have different charging voltages, ranging from 13.8 to 14.7 for bulk. So depending on which brand I select, they work fine with my AGM start and existing alternator and solar charging programmes, or I need a DC-DC charger which adds $500 minimum and means I may as well go with lithium.
Then there is the marketing spin. My old US2200's have the same statements of not needing to recharge fully as the Pb-C batteries. That clearly didn't age well.
And I can pay anything from $750 to $2,300 for batteries that do the same thing. I could pay north of $5k if I listen to the sales guys fear and panic speach (only his lith batts are certified for use in marine, and ALL others will void your insurance, despite the other sales guys saying their product is fine for marine, and challenging me to kill the battery, as they state their BMS is so good I wont be able to get around it...)
Anyway, my current batts are holding at 12.73v, which is promising, so we will do some more sussing to see if we can keep them going for a bit. An equalisation charge and a load test. And just to cover my options for the July school holidays, my father has a 'spare' pair of new AGM's in his trailer home we can drop into the boat. That will cover me for cruising while I untangle all the new batt options, and also verify if we have parasitic loads on the boat. The logic being, if brand new good condition batts do strange things, we will know it is an issue in the boat. If the new / borrowed AGM's are fine, then I know it is an age / capacity / internal micro-short on my current LA's.
This all makes hiring a bach look like a nice option.
|
|
|
Post by Cantab on Jun 8, 2023 10:10:35 GMT 12
My monies on problem on your boat. Use an ammeter, start at the battery and find out where its going. If you got Solar your batts should be fully charged every time you get back to your boat.
|
|
|
Post by GO30 on Jun 8, 2023 12:00:09 GMT 12
So far I can say looking for and trying to select new batteries is like going down a rabbit hole. Oh hell yes and not just batteries but they do seem to be in the leading pack.
I've just designed some small solar systems for a Pacific Island. The locals are 'borrowing' the solar Nav lights to use for home lighting so if we can provide some solar systems then maybe the ships etc won't drive up the reefs while looking for the non existent Nav lights. In working thru that the amount of smoke, mirrors, pure thieving bastards and taking the piss going out there is just wrong.
|
|
|
Post by fish on Jun 8, 2023 13:06:44 GMT 12
My monies on problem on your boat. Use an ammeter, start at the battery and find out where its going. If you got Solar your batts should be fully charged every time you get back to your boat. OK, We've put on a battery monitor which is giving us amps in and out of the batt. I assume you mean a digital clamp meter? I don't have one of those but see there are a few options for about $70. I had an idea to get one that was any use you needed to spend substantial sums? Anything to be aware of with buying cheap digital clamp meters?
|
|
|
Post by Cantab on Jun 8, 2023 14:34:07 GMT 12
No, you need to disconnect the main battery cable and put a multimeter in series, you are looking for milliamps. If it reads zero all good. If not, you go through your distribution system checking each circuit until you find out where its all going.
|
|
|
Post by fish on Jun 8, 2023 15:50:57 GMT 12
No, you need to disconnect the main battery cable and put a multimeter in series, you are looking for milliamps. If it reads zero all good. If not, you go through your distribution system checking each circuit until you find out where its all going. That makes much more sense. We never thought one of those digital clamp meters was much use. The battery monitor should give us the same information, it has a coulomb meter in series in the battery cable. I will check the accuracy / resolution of it.
|
|
|
Post by Fogg on Jun 8, 2023 16:14:24 GMT 12
Unless you’ve got a very whizzy battery monitor it won’t give you the sensitivity you need to do any diagnosis. It’s just a rough guide to the nearest 0.1-0.2 (if you’re lucky).
|
|
|
Post by fish on Jun 9, 2023 18:46:53 GMT 12
Well, what a complete clusterfuck. Bloody Farken boats...
Where do I start? Firstly @cantab, I owe you a bottle of whisky (or what ever poison you take). Which part of the country are you in? Using the multimeter in parallel to check for mA parasitic loads was exactly what we needed to do.
Today's objective was to go to the boat and confirm there we no electrical issues external to the batteries. And to confirm the current settings of our charge controllers, so as to confirm exactly what we need to do to install new batts and charge them properly.
Well, that went sideways: 60mA parasitic load with the main isolator off. 50mA is the screen for the battery monitor, but without it the battery monitor still blu-tooth's to my phone, so bye-bye screen 0.19A parasitic load with the isolators on, but no items turned on. That is about 5 Amphrs / day, and over 30 days easily enough to completely flatten and shag the house batts. Haven't been able to work out what that is, BUT The Voltage Sensitive Relay is really fucking things up. There is a little float panel on the start batt. 25W. It appears that this can get the VSR to open (opens at 13.7v, closes at 12.8). When it is open the start battery float panel is charging the house batts (we installed my fathers new AGM's to do all this testing). But when the sun goes off the panel, the house batts start charging the start batt, like, WTF?!?!
Then, the start batt couldn't start the engine. It was at about 13v, but possibly a surface charge from the solar with 1amp actual charging. Paralleled the house and start and got the engine going. Then the alternator regulator was saying the batt voltage it was monitoring was 11 something volts. Voltage sensing lead is on the house batts (as per instructions, put it on the largest batts, but I don't get why its not on the start batt). House batts were at 12.8 rested, and have been all week. So something is wrong for the regulator to be seeing 11 something.
Decided to bring the start batt home for a proper charge and a once over. Extracted it from where it lives, then accidentally left it on the boat and went home. Fuck it. At any rate, we will be able to get a resting voltage on it, as we only ever check its voltage when the little float panel has been giving it some ergs. I think that is all the issues we found, oh, accept the alternator went to 15 something volts for a bit, when it was only supposed to go to 14.8
On the old batts, I found a US based spec sheet. They are US batteries US2200. Some of the charging requirements are different to the NZ based Hella Endurant charging requirements. There is a requirement for the charge current to be max 0.1C, which equates to 23amps. Our alternator can go to 51 amps which is about 0.2C, and I've seen it giving these batts 30 amps ish and when they were at 7v, it was giving them a thick 40 amps. Also the float charge is 13.0, where Hella Endurant said 13.5. This could explain some of the issues on short life with these batts, in addition to the clusterfuck of parasitic loads. The 60mA with the isolators off is the batt monitor, and we only installed that recently (late summer?). But clearly there are major issues when I leave the isolator switch on by accident. We are going to install a relay that will isolate the house batt on low voltage. The new batt monitor can do all of that, it will be like a DIY BMS.
But the good news is, the supplier of the new house batts I like the most have 10% off at the moment. I asked them for a checky discount (about 4%, based on buying 3 batts for the discount price based on buying 5 batts) they came back and said they are running a 10% offer via the motor caravan association, of which my father is a member. SO I can get 300Ahrs of lead carbon batts for $840, 2 yr warranty. They might not be that great compared to top shelf lead carbon or lithium, but they are basically AGM batts, and at that price are the same or cheaper price point that standard AGM's.
Lucky they have 10% off, as I may be needing a new start batt, and possibly a full re-wire... The Balmar smart regulator and the VSR are maybe 20 years old, so we wont be surprised if some hardware item has shat itself. We are also starting on a full disassemble, clean, check and reassemble of the entire heavy duty electrical side, and a similar process for the distribution wiring. Like I sad, bloody farken boats. Possibly need block diodes to stop the house batt back-feeding to the start, but we will park that until we've confirm the VSR is working properly and doesn't need replacing with something fancy, like a MOSFET battery isolator, or even a DC-DC charger (which would allow me to chuck on lithiums easy peasey)
So today was productive in terms of determining the extent of the issues, but frustrating that we found so many issues. All whilst thinking we knew what we were doing and thinking we look after our boat well. Fuckit.
|
|
|
Post by jim on Jun 9, 2023 19:34:53 GMT 12
Far out - buy two bottles of whiskey , one for Cantab and one for yourself which you should scupper down tonight...
|
|