Ivylog Posted September 27, 2021 Share Posted September 27, 2021 In another post I mentioned I’d built 600AH of Lithium batteries for $1200 plus 15 hours of my time making them price competitive to AGMs but 5X the life. Searched AliExpress and found 8-280AH cells for $358…560AH of batteries for probably $500…90 cents/AH. Today I searched again and found 8-310AH cells for $346. Add $84 for 2 BMS (200A is big enough) and $50 in cables… 620AH for $580…91 cents making them as cheap as lead/acid but probably 10X the life. Sorry but the address I copied for the cells did not paste but searching the Ali site you should be able to find them. Below is a 8 month old Video on making your own batteries. A BMS that requires soldering the cables on is only $40. 1 Link to comment Share on other sites More sharing options...
Dear LaserWorks Posted September 27, 2021 Share Posted September 27, 2021 Just be sure you know what you are getting. We would only purchase cells that are guaranteed to be both "New" and "Grade A". Also, we are avoiding 300Ah or higher as those seem to bulge for everyone when fully charged. Shipping costs from China have gone through the roof as well and may not recover until 2023. 2 Link to comment Share on other sites More sharing options...
Gary 05 AMB DST Posted September 27, 2021 Share Posted September 27, 2021 I had no idea what the movie was talking about. To keep the MH and myself in the same era that it was built, I am sticking with lead acid batteries. Gary 05 AMB DST 2 1 Link to comment Share on other sites More sharing options...
vito.a Posted September 27, 2021 Share Posted September 27, 2021 Dick, thanks for posting. What BMS did you use? I think we are just seeing the first of many price reductions on LiFePO4 cells. David, if you watch the Will Prowse YouTube videos he tests some "B" grade cells with very good results. The problem is within a few days after his video is published the price skyrockets or they run out of stock. 1 Link to comment Share on other sites More sharing options...
JDCrow Posted September 27, 2021 Share Posted September 27, 2021 24 minutes ago, Gary 05 AMB DST said: I had no idea what the movie was talking about. To keep the MH and myself in the same era that it was built, I am sticking with lead acid batteries. Gary 05 AMB DST All depends on your next adventure. Loads of coaches never wander off the pavement or become untethered from 50 Amp service. The Genset takes care of lots of power questions Just a new tool in the box for some. I went lithium, I’m just not as adventurous (yet) to build my own 2 Link to comment Share on other sites More sharing options...
Dear LaserWorks Posted September 27, 2021 Share Posted September 27, 2021 5 minutes ago, vito.a said: David, if you watch the Will Prowse YouTube videos he tests some "B" grade cells with very good results. The problem is within a few days after his video is published the price skyrockets or they run out of stock. Vito, yeah, I've watched way too many of his videos. 🙂 He's in a league of his own for sure. I'm mostly wary of winding up with used cells, really, more than grade B. There are sellers that stock Grade A, new, in the US for immediate shipping. It's not cheap, but still less than half the cost of Battleborn, and no waiting for your ship to come in, literally, from China. Link to comment Share on other sites More sharing options...
Ivylog Posted September 27, 2021 Author Share Posted September 27, 2021 I figure nothing ventured, nothing gained… finally got payment confirmation of the 310AH cells. Vito, I don’t need a WiFi smart BMS so one that requires some soldering. I did but a monitoring system (below) and will buy another one when I DIY these cells. AiLi Voltmeter Ammeter Voltage Current Meter Voltmeter Ammeter 100V 350A Caravan RV Motorhome 999 AH 8-80V,0-350A Purchased 1x.Last purchased on May 19, 2021 $44.00$44.00 1 Link to comment Share on other sites More sharing options...
Dear LaserWorks Posted September 27, 2021 Share Posted September 27, 2021 2 minutes ago, Ivylog said: I figure nothing ventured, nothing gained… finally got payment confirmation of the 310AH cells. Not a lot to lose, for sure, relatively. Please keep us posted on the cells, seller, shipping time, etc. Thanks! Link to comment Share on other sites More sharing options...
Ivylog Posted September 27, 2021 Author Share Posted September 27, 2021 52 minutes ago, Dear LaserWorks said: Not a lot to lose, for sure, relatively. Please keep us posted on the cells, seller, shipping time, etc. Thanks! Supposedly 30 days… will see and post. Building your own battery is not that hard and even if your charger doesn’t have a Lithium profile, using a AGM setting will get you to 90%. Agree if you are a 50 amp to 50 amp CG person going Lithium, even at lead/acid prices is probably not worth the DIF effort although like AGM, corrosion is not a issue. Link to comment Share on other sites More sharing options...
Andrew Sibley Posted September 27, 2021 Share Posted September 27, 2021 I don't know much about this but am interested in trying this. In checking that website, it seems like prices for 310 ah cells are all over the board. I think I saw one option for 8 grade A cells for $280. Maybe I'm looking wrong. Perhaps someone can try again to get a link that works because maybe I'm missing something. Link to comment Share on other sites More sharing options...
cbr046 Posted September 28, 2021 Share Posted September 28, 2021 I'm not impressed with the dry-as-a-bone FLA batts that came with our coach. I'll milk them as long as I can but when they won't last a night I'll consider Lithium if the price was competitive. Getting the BMS right and not melting the alternator are key concerns. - bob Link to comment Share on other sites More sharing options...
Ivylog Posted September 28, 2021 Author Share Posted September 28, 2021 (edited) I have 880 AH of AGMs and will run the generator for an hour in the morning before getting on the road. That still puts a good load on the Alternator so I put a remote temperature probe on it. Unfortunately I cannot monitor charging amps from the drivers seat, just voltage, but 185 is the highest temp I’ve seen in a engine compartment that runs 280 (180 not 280) degrees. I’m not going to use a DC-DC buffer to start with and if the alternator doesn’t get hotter than 195 charging the Lithiums, I will not add one. Edited September 28, 2021 by Ivylog Link to comment Share on other sites More sharing options...
JDCrow Posted September 28, 2021 Share Posted September 28, 2021 57 minutes ago, cbr046 said: I'm not impressed with the dry-as-a-bone FLA batts that came with our coach. I'll milk them as long as I can but when they won't last a night I'll consider Lithium if the price was competitive. Getting the BMS right and not melting the alternator are key concerns. - bob 57 minutes ago, cbr046 said: I'm not impressed with the dry-as-a-bone FLA batts that came with our coach. I'll milk them as long as I can but when they won't last a night I'll consider Lithium if the price was competitive. Getting the BMS right and not melting the alternator are key concerns. - bob Ditched the Bird when I went lithium and got a DC/DC Victron which can be monitored. The battery I picked up can take 100 Amps on. After watching the Victron video on YouTube of frying alternators, I was sold, but I guess that’s the point of the video LOL 4 Link to comment Share on other sites More sharing options...
Dear LaserWorks Posted September 28, 2021 Share Posted September 28, 2021 49 minutes ago, Ivylog said: I have 880 AH of AGMs and will run the generator for an hour in the morning before getting on the road. That still puts a good load on the Alternator so I put a remote temperature probe on it. Unfortunately I cannot monitor charging amps from the drivers seat, just voltage, but 185 is the highest temp I’ve seen in a engine compartment that runs 280 degrees. I’m not going to use a DC-DC buffer to start with and if the alternator doesn’t get hotter than 195 charging the Lithiums, I will not add one. One good way to protect your alternator is to replace your solenoid with a LiFePO4 Battery Isolation Manager (BIM) for $175. https://battlebornbatteries.com/product/lifepo4-battery-isolation-manager/ Click on the "Features" tab & you'll see how it cycles ON/OFF to prevent your alternator from overheating. "Under normal charging conditions, the BIM will connect for 15 minutes every 35 minutes. That means that the BIM will connect for 15 minutes, disconnect for 20 minutes, and repeat this cycle until the coach battery is charged." Link to comment Share on other sites More sharing options...
Ivylog Posted September 28, 2021 Author Share Posted September 28, 2021 I’m not convinced that the alternator is going to put out its full 200A just because it’s charging Lithium instead of AGM. I have a dedicated 100A charger for my 600AH of Lithium and the most it’s ever put out is 67 amps into them… 11 amps/battery even though each BMS is rated 60 amps. When they get near fully charged, the amps decrease as each BMS takes its battery out of the loop… all the way down to 6 amps. When I build 2- 300amp batteries I’m not going with an expensive 300A BMS for each battery. 150A would probably be enough, although I’ve bought 2-200A, as I can’t charge 300A and the micro (biggest amps) draws less than 200A. Link to comment Share on other sites More sharing options...
waterskier_1 Posted September 28, 2021 Share Posted September 28, 2021 22 hours ago, Dear LaserWorks said: Vito, yeah, I've watched way too many of his videos. 🙂 He's in a league of his own for sure. I'm mostly wary of winding up with used cells, really, more than grade B. There are sellers that stock Grade A, new, in the US for immediate shipping. It's not cheap, but still less than half the cost of Battleborn, and no waiting for your ship to come in, literally, from China. I believe that Grade B includes used. 18 hours ago, JDCrow said: Ditched the Bird when I went lithium and got a DC/DC Victron which can be monitored. The battery I picked up can take 100 Amps on. After watching the Victron video on YouTube of frying alternators, I was sold, but I guess that’s the point of the video LOL I have not been able to tell if the Victron DC/DC Charger is able to allow charging chassis battery from shore power. Not many would want to do this, but it would be good to know. 17 hours ago, Dear LaserWorks said: One good way to protect your alternator is to replace your solenoid with a LiFePO4 Battery Isolation Manager (BIM) for $175. https://battlebornbatteries.com/product/lifepo4-battery-isolation-manager/ Click on the "Features" tab & you'll see how it cycles ON/OFF to prevent your alternator from overheating. "Under normal charging conditions, the BIM will connect for 15 minutes every 35 minutes. That means that the BIM will connect for 15 minutes, disconnect for 20 minutes, and repeat this cycle until the coach battery is charged." I personally don't recommend this. Yes, it will protect your alternator, but it still only provides 14.4 (or whatever your alternator charging voltage is) to the Lithium batteries, even if only on for 15 minutes and off for 20 minutes. The Victron DC/DC Charger is a full fledged 3-stage battery charger. 1 1 Link to comment Share on other sites More sharing options...
Ivylog Posted September 28, 2021 Author Share Posted September 28, 2021 (edited) 18 hours ago, Dear LaserWorks said: Under normal charging conditions, the BIM will connect for 15 minutes every 35 minutes. This ^^^ got me to thinking as I already have a switch that lets me disable the BigBoy when dry camping… it’s about a 4 amp draw all the time which adds up. Bought a $5 programmable timer that I’ll add to that circuit so I can cycle the charging of the house batteries similarly to the $172 BIM. 1PCS Multifunction Digital Time Infinite Delay Switch Timer Relay Module DC 5V / 12V / 24V If you go to the Amazon link below, at the bottom of the description there are several videos of what you can do with one. https://www.amazon.com/UCTRONICS-Programmable-Multifunction-Segment-Automatic/dp/B07BT32T1M/ref=mp_s_a_1_8?dchild=1&keywords=1PCS+Multifunction+Digital+Time+Infinite+Delay+Switch+Timer+Relay+Module+DC+5V+%2F+12V+%2F+24V&qid=1632857777&sr=8-8 As for a alternator not fully charging a LifePo4…13.6 is 100% which is well within a alternator output voltage. Table below is for a LifePo4 12V battery. And to further hijack my own thread… when not using Lithium batteries for several months, it’s better to have them at 50% (13.15V) so the lithium anode doesn’t degrade. Edited September 28, 2021 by Ivylog Link to comment Share on other sites More sharing options...
waterskier_1 Posted September 28, 2021 Share Posted September 28, 2021 58 minutes ago, Ivylog said: I’m not convinced that the alternator is going to put out its full 200A just because it’s charging Lithium instead of AGM. I have a dedicated 100A charger for my 600AH of Lithium and the most it’s ever put out is 67 amps into them… 11 amps/battery even though each BMS is rated 60 amps. When they get near fully charged, the amps decrease as each BMS takes its battery out of the loop… all the way down to 6 amps. When I build 2- 300amp batteries I’m not going with an expensive 300A BMS for each battery. 150A would probably be enough, although I’ve bought 2-200A, as I can’t charge 300A and the micro (biggest amps) draws less than 200A. The BMS doesn't limit the amount of current as you are thinking. It is rated at a maximum current it will pass before it self destructs (likely with smoke). It's the difference in voltage and the internal resistance of the battery (and the battery cables) that determines the amount of current. That is the problem with connecting Lithium directly to an alternator without some protection device (see above for two that have been mentioned). If the Lithium batteries are quite low, and you have low loss cables connecting them, you should be able to charge them at 1"C" where "C" is the battery Capacity in Amp-Hours. If you indeed have 600 AHrs, then with an appropriate sized source (and an appropriate sized BMS that won't smoke) you should be able to supply 600 Amps until almost fully charged. I haven't tried this, but I won't build a battery any larger than 280-300 AHrs. I will parallel more than one of those batteries though. I'm using a 150 Amp rated BMS, and with two in parallel, there is no way I can exceed that with the current charging sources I have (180 Amp Alternator, but limited by a DC/DC chrger, and Victron MultiPlus with 130 Amps battery charger). So the most I could see is 65 Amps from the MultiPlus. I also have 1400 Watts solar on the roof, 1300 Watts dedicated to the coach battery. That could provide a maximum of 104 Amps, in perfect conditions at noon on the equator. So that won't be a problem either. But my design is not to be able to charge my batteries back to 80% in an hour or less. If it does it in 5 hours I'll be happy. 2 Link to comment Share on other sites More sharing options...
waterskier_1 Posted September 28, 2021 Share Posted September 28, 2021 21 minutes ago, Ivylog said: This ^^^ got me to thinking as I already have a switch that lets me disable the BigBoy when dry camping… it’s about a 4 amp draw all the time which adds up. Bought a $5 programmable timer that I’ll add to that circuit so I can cycle the charging of the house batteries similarly to the $172 BIM. 1PCS Multifunction Digital Time Infinite Delay Switch Timer Relay Module DC 5V / 12V / 24V If you go to the Amazon link below at the bottom of the description there are several videos of what you can do with one. https://www.amazon.com/UCTRONICS-Programmable-Multifunction-Segment-Automatic/dp/B07BT32T1M/ref=mp_s_a_1_8?dchild=1&keywords=1PCS+Multifunction+Digital+Time+Infinite+Delay+Switch+Timer+Relay+Module+DC+5V+%2F+12V+%2F+24V&qid=1632857777&sr=8-8 As for a alternator not fully charging a LifePo4…13.6 is 100% which is well within a alternator output voltage. Table below is for a LifePo4 12V battery. And to further hijack my own thread… when not using Lithium batteries for several months, it’s better to have them at 50% (13.15V) so the lithium anode doesn’t degrade. I'm not sure if you were directing this comment to me, but the problem has never been that the alternator could not charge the Lithium batteries fully (if you really want them at 100% SOC). The problems or concerns were 1) that the alternator could overheat in the process, and 2) it isn't good for fully charged Lithium batteries to be held at 14.4 volts for long periods of time. Many are not thinking about the second concern. That is the difference between Battleborn's backyard mechanic approach and the Victron approach. Link to comment Share on other sites More sharing options...
JDCrow Posted September 28, 2021 Share Posted September 28, 2021 (edited) 3 hours ago, waterskier_1 said: I believe that Grade B includes used. I have not been able to tell if the Victron DC/DC Charger is able to allow charging chassis battery from shore power. Not many would want to do this, but it would be good to know. I personally don't recommend this. Yes, it will protect your alternator, but it still only provides 14.4 (or whatever your alternator charging voltage is) to the Lithium batteries, even if only on for 15 minutes and off for 20 minutes. The Victron DC/DC Charger is a full fledged 3-stage battery charger. No on the DC/DC charger charging chassis battery while on shore power. The alternator charges while engine running, and my Multiplus 2 has a 4amp trickle charger when hooked to shore power. The DC/DC just takes alternator juice and necks it down to 30 amps. And you can refine it for the type of battery you want to charge, such as lithium since they are on a different charge pattern than lead. Edited September 28, 2021 by JDCrow 1 Link to comment Share on other sites More sharing options...
milly59 Posted September 29, 2021 Share Posted September 29, 2021 well i plunged and bought 8 3.2V grade A 310ah batteries...and will install those they are saying 4 to 6 weeks delivery...shipping was free and i paid $545. do i need 2 bms with 8 batteries? will do 4+4 to have the 12 volts.....anybody else installed those batteries? do they work as advertised...for the people that have installed them? Link to comment Share on other sites More sharing options...
Ivylog Posted September 29, 2021 Author Share Posted September 29, 2021 42 minutes ago, milly59 said: do i need 2 bms with 8 batteries? will do 4+4 to have the 12 volts.... Did you read my first post at the beginning? Link to comment Share on other sites More sharing options...
waterskier_1 Posted September 30, 2021 Share Posted September 30, 2021 5 hours ago, milly59 said: well i plunged and bought 8 3.2V grade A 310ah batteries...and will install those they are saying 4 to 6 weeks delivery...shipping was free and i paid $545. do i need 2 bms with 8 batteries? will do 4+4 to have the 12 volts.....anybody else installed those batteries? do they work as advertised...for the people that have installed them? I recommend two BMS, because I recommend you build two batteries. Note that a battery is made up one or more cells. One reason I say this is because you'll not likely be able to lift and install the battery if it contains all 8 cell (est. about 100 lbs). You could use one BMS if you put all the cells in a single battery, but you will have to limit charge and discharge currents since I'm not aware of any BMS's rated for 600 Amps. I have not use those batteries - they are relatively new on the lower cost market, and don't have a sufficient quality record yet. My recommendation is to order only new, Grade "A", tested and matched, cells from a reliable supplier. There are many unscrupulous sellers who are selling seconds, unmatched seal removed, and often used cells. If your ordering a large quantity (over 100) cheap enough, you can test them, match their internal resistance, and capacity and hand select cells to put together, some have found good results. Most of us don't have the time or interest mush less the text equipment to do that. 2 Link to comment Share on other sites More sharing options...
Dear LaserWorks Posted September 30, 2021 Share Posted September 30, 2021 On 9/28/2021 at 3:39 PM, waterskier_1 said: I have not been able to tell if the Victron DC/DC Charger is able to allow charging chassis battery from shore power. Not many would want to do this, but it would be good to know. I personally don't recommend this. Yes, it will protect your alternator, but it still only provides 14.4 (or whatever your alternator charging voltage is) to the Lithium batteries, even if only on for 15 minutes and off for 20 minutes. The Victron DC/DC Charger is a full fledged 3-stage battery charger. Rick, how do you wire in a DC-DC charger and retain the ability to boost with both batteries if needed? Link to comment Share on other sites More sharing options...
JDCrow Posted September 30, 2021 Share Posted September 30, 2021 7 minutes ago, Dear LaserWorks said: Rick, how do you wire in a DC-DC charger and retain the ability to boost with both batteries if needed? You don’t to my knowledge. The link to the battle born site with the isolator may be the ticket. I honestly didn’t want the bird anymore. I can use the toad and jumper cables if needed I figure Link to comment Share on other sites More sharing options...
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