The cart is getting all new brake cables and brake shoes. We have to straighten the front axle in a press… somebody hit something a lil too hard and bent things.
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You will need to put a crash bummer on by the sounds of it. Reminds me of a friend who explained that the 4 wheeler I sold him needs a new front grill. I thought funny I bought it new in 2004 and it never needed any body work in the time I owned it. Apparently I sold it just in time as the trees learned how to jump out in front of it recently.
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We went and looked at an electric Geo Metro conversion today. This motor in it, is worth more than he is asking for the car.
Really, I don’t see any difference in how this car is set up, than the golf cart. Even has a Curtis controller.
I really AM going to have to study this LFP battery chemistry.
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O.K. You made me look.
Searched LFP = Lithium iron phosphate
I’m not saying wikipedia is the know-all, end-all info source. But certainly a good starting point.
Interesting. Shows potential use as an automotive lead acid service battery replacement. And home bank usage.
On the other topic line Bruce you threw out LTO. I had to search that one too.
LTO = Lithium-titanate-oxide battery
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Just an update on this…it needs paint, and the inverter and charge controller wired in properly. We pressed it into service because we were redoing the camp roof and I got tired of walking back and forth.
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Charging the electric car with the golf cart.
Inflating tires with the cart.
There have been mishaps. I hit the throttle instead of the brake and flipped the cart a bit, dumping all the electronics overboard…then panicked and floored it. I wish I had a video of that…
I do like 48v, and recommend it.
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48 volts.
I’m heading this way now too.
As I told you Bruce J. I decided to go with top post Group 31’s in all the rigs here.
Ha! Then if-ever; then-fuels-restricted I can pull them and bank up.
Ha! With the in-use rigs keeping them conditioned.
Another one just converted over this morning:
Ha! Ha! Had to make of course a wooden floor plate to not have the original tray edge cut into the bigger heavier battery bottom. Hey Marcus Norman89 I used a western red cedar shingle. Keep you working.
Finished. Had to relocate the wiring harness’s both sides. And flatten two harness support tabs. Had to lose the P-post cover. Too tall holding up the fresh air snorkel.
Two more vehicles to convert and then I’ll have five same-same working. (Too chicken to do the wife’s SUV)
Onwards, forwards
Steve unruh
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I went out back a half mile, over a rock pile, logs, and etc. I was heading for some sugar maples I pushed over, making a pathway along the property line. I hit a bump. I broke a weld. I had the framework holding the solar panels come loose. I was stubborn, and cut wood, until the inverter whined about the stupid bldc saw drawing too much watts.
I still managed to drive back to the shop. If you look at the last photo of the cart, you’ll notice no bolts on the bottom green bar of the framework. Apparently, I spaced off and forgot to put them in. The other side has them. Anyhow, Charlie put them in, and I rewelded the roof.
We also keep an extra tarp over the electrical box.
Today, I used the cart to power the oil shed pumps, and moved another 50 gallons of biodiesel out of the reactors and into the wash tank.
@DanNH I really like the signeer 48v inverter. Thanks for recommending it. I am now shopping for the 6000watt 48v inverter. I was going to sell the belsaw circular mill, to pay for it, but I might just buy it now before the price goes up. The 3000 watt Signeer jumped up by $50.
I also really like those AGM batteries, by Remy.
I watch Will Prowse on YouTube, as he brings out the latest LiFePO4 batteries. I found a real snag concerning these. The battery management systems MOSFETs cannot handle more then 48v. So LiFePO4 would be ok for the carts or solar or a tractor…but we cannot use them in their present form in the electric Geo. The Geo motor needs 144vdc, or rather it’s motor controller needs 144vdc.
I was doing reverse drifting, and an e-brake spin, and got the motor spiking up to 300amps, and had the voltage drop down below 72vdc, and the motor controller cut out. Four more batteries and I could have had the controller cut out do to high amps.
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I have not been to impressed with Will Prowse he is often in over his knowledge base. He is simply wrong on this one. For a 144 volt system you need a 48S BMS for Lifepo4. You should be able to find them all the way up to 600VDC without much issue I know the 48S are commonly available online I have looked at them for a tractor project in my distant future. Check out this YouTube channel.
Jehu Garcia has built his own business out of his love of building EV conversions and battery packs. He talks about how the EV market uses relays to handle the current load. Basically you wire a small BMS to monitor the batteries to a larger relay. When the BMS trips it trips the high current relay. You should have that relay already in the Geo and should just need the low cost low current BMS.
I am glad the inverter worked out I did see the price has jumped. I haven’t found a cost effective solution to a higher wattage inverter. I honestly gave up looking for one and bought a DC motor for my project instead of trying to use an AC motor I have on hand.
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@DanNH
I need to clarify. Will was displaying drop-in 12v LiFePO4 batteries. My first choice is a drop-in replacement. Building my own battery will be an armchair exercise, until I get a slough of free batteries. I definitely am not paying for parts that I have to build. I am just not smart enough or careful enough to pull it off. The longer I hangout with the robot teams, the better my wiring skills are improving.
Do you think batteries are going to continue to drop in price, inspite of the potential inflation?
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He is correct that the drop in batteries at 12 volts won’t allow you to hook them up in serries. It has to do with the way they designed the BMS in the box. I looked into that in detail a while ago and decided to build my own but I have decades of experience working with electronics.
Will battery prices continue to drop? Yes they are going through the economy of scale we saw on solar panels over the last 15 years. I would guess over the next 5 to 7 years the price of storage will drop in half as all the new factories come on line and the EV market takes off. There will be growing pains and it will largely depend on how well the market guessed the demand for EV. It looks to me like 2022 will be a tight year but by 2025 I suspect we will see a major drop in price and probably a new cell chemistry take the lead. There are a few on the verge of commercialization at the moment the next year will sort out if they can be scaled up to mass production or not. My take on the battery market is about the same as the EV market as they are the major customer. I think for 2022 the economy will continue to be very tight but that it won’t impact EV sales. I believe the interest in EV and the acceptance of them as the future of transportation is far enough along now that the slow down will come in the form of a drop in ICE sales and the EV market will remain supply limited maybe as far out as 2025. That said with all the factories comming on line to build batteries and the downward pressure form companies like GM and Ford on the battery manufacturer for price I think the cost will continue to fall. Big companies negotiate prices for a year or more when they enter deals at the scale we are seeing in that market. I have been in those negotiations before it is shocking how much pressure you can put on a supplier when you are discussing over 1 million dollars in sales per year. I once gave a major electric motor manufacturer what I thought was a crazy low price point less than half the list price and in 3 months time they came back and told me that they thought I would like their next offer it was 15% below what I had requested. I was very impressed as the competitor I was using was about 15% above the number I had given them in the first place. These companies know how to cut margins with their suppliers which will force the battery companies to optimize the production lines.
If I was in your situation I would look into the large single cells for that Geo. I forgot the name for them off the top of my head but they are common in the DIY community. You simply bolt a ring terminal to the top of each cell hooking them in the serries parallel configuration you want. The BMS hooks up to the most negative terminal in the pack and to each positive then pulls in a relay contactor for the main output of the pack. Not much harder to hook up than the 4 12 volt batteries you hooked up already except that there are more connections. Buying small 18650 cells and building a bigger pack is a lot more work for the cost savings. I have been going down that road and honestly I am not convinced it was worth the savings. But I am far enough along that I will finish this project.
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I have 8 drop in lifepo4 120 AH batteries that are able to just replace the old lead acid /AGM ,GEL cells and they have inbuild active balance and BMS , and can be wired in series but only to created 26 volts , there BMS is not powerful enough to use as a cranking battery and so i bought a Hybrid cranking battery of 25AH with 1900 ccc of Maxwell super caps all in the size of a small car battery , its the most amazing sound hearing it spin up a 4 liter petrol engine like it was taking off on steroids, the engine fires up so fast and will never go back to lead acid after using this , for maybe a $100 bucks more than a standard size battery for my size truck and a life of 20 plus years its a no brainer for me .
Dave
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How long can the supercaps hold a charge without incoming current topping it off?
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Maxwell 500f have a discharge of around 50% after 3 days , but i could be wrong it could be tons less than that , because the hybrid battery i have also have lifepo4 cels in built it may take many months before its down too low to start the truck But if that’s the case it only takes a few mins to fully recharge the caps again to start the engine with no damage of the battery or caps at all and once driving the caps and battery are fully topped off again
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I had my first failure of the Remy AGM 31 series today. To be fair it was a starting battery for the excavator, not on the golf cart. Those batteries seem to be doing fine. The battery that failed would only give three volts when the excavator engine was cranking. The remarkable thing was when I went to Remy to possibly buy a set of replacements they told me it would be $730 for two of those batteries. Needless to say I went home without them.
We have started buying calb lithium iron phosphate cells. They are 100 amp hour at 3.2 volts for 100 bucks. The manufacturer claims that they have 2000 cycle life. I don’t know if they’ll work for starting batteries or not but the price is comparable to lead acid so it might not hurt to try. For sure the h is getting its magneto and hand crank again.
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I think the only issue you’ll run into is charging them, not sure what your alternator/generator would put out for a 4S of those cells. I hear conflicting stories about replacing your starter battery with lithium. Motorcycle guys saying they love it, RV guys saying don’t do it. Annoying and confusing.
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And boat guys saying lithium is the ONLY way to go
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You will definitely want a good BMS if you use lithium ion for a starter. The issue as said by others is the charging voltage. I would look into the generator or alternator and voltage and regulating it to meet the charging voltage of the lithium batteries. Also don’t charge lithium batteries below freezing temps some of the chemistries will definitely electro plate the lithium on the wrong side of the battery when they are too cold to charge. I am too tired tonight to remember all the details of the charging of lithium. But over charging or cold charging will definitely damge them.
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