| Got to watching an old movie last night and while I was at it I went ahead and put the cells in the battery case. WoW talk about a perfect fit. I used some 1/8th" high density foam mat to sandwich the cells tightly inside the box, one piece on each end. The foam was packing material from the lift kit. lol None of the cells actually touch the case anywhere. Lord help me if they ever need to come back out they are in tight. I still need to figure out some way to lock them in place side to side where there's a 1/4 inch gap between the cells and walls for airflow. If anyone has any ideas I'm all ears. I also need to maneuver them a little to get the aligned properly. Again No idea how as tight as they fit. |
BED FRAME ANGLE IRON
CUT UP
CUT UP
BMS Came in yesterday. I had left ample room to mount a hundred amp BMS inside the box. There is NOT room for this 250 amp BMS inside though. Either going to have to mount it externally or maybe half in half out or make a larger box. UGH Oh well I've about decided to leave the batteries in it for now they are doing so much better than when I first got them. The long slow solar charging has worked wonders with them. For the summer my new Li bank may end up running our AC over night. We use to run the generator for it at night but with gas so expensive now........
It was nearly an all day ordeal but I finally managed to shoehorn the BMS mostly inside the battery box. It looks like I may have a couple problem cells. One is rather much higher than the others and the other is a little lower than the others. The BMS appears to be trying to balance them as the numbers are SLOWLY getting closer together.
I've got the Li battery in the house running the AC. Might wait until fall before I put it in the GC. The batteries in there are doing okay. I am also toying with the idea of going ahead and swapping them and trying to use the existing GC batteries to run the AC. I would really like to have this one in the GC for the added performance and weight loss but being able to run AC all night without using gas is worth a lot considering how much fuel has gone up. Still thinking on it.
Yep, if the gc batts are even somewhat close to the Li batt in Kw hrs, then the energy saved by not lugging around the extra weight would be worth the swap.
They are old crown 155AH @ the 20 hour rating or 140 @ the 5 hour rate. My new Li setup is 105AH and I think that's a one hour rating. The weight and space savings will be huge and the few more volts should help a little also. The lead acid batteries are supposed to be 51.2 when fully charged but I seldom see more than 50.6 and that drops fairly quick. The Li setup can go as high as 56.4 and is pretty well dead at 50 but can safely go as low as 42.
I like to just use kwhr rates as a comparison ( AH x battery nominal voltage ). So mine is a 103AH with a nominal voltage of 51.4v = 5294KwHrs
It gets complicated when you introduce discharge rate ratings as this is reflective of the C rating, or how much energy is lost to heat and measuring available KwHrs at certain constant discharge rates and temperature. It's really the same as a gas tank in an ICE vehicle, the capacity of the gas tank stays the same, but how efficiently you drive has a drastic effect on the available range you have.
It gets complicated when you introduce discharge rate ratings as this is reflective of the C rating, or how much energy is lost to heat and measuring available KwHrs at certain constant discharge rates and temperature. It's really the same as a gas tank in an ICE vehicle, the capacity of the gas tank stays the same, but how efficiently you drive has a drastic effect on the available range you have.
Okay so these are 105AH with a nominal voltage of 51.2. Pretty much the same amount of storage. Your motor & controller setup is super efficient compared to the old resistor coils setup I'm running. Hopefully I can upgrade one of these days. My pockets are pretty shallow though so I'm not holding my breath. lol
Think I've got some broken frame welds. I can feel the cart flexing and twisting under me and now it's snapped both the rear roof struts at the bolt holes where it attaches to the seat frame. I'm not surprised I mostly keep this poor thing in places it was never designed to go. I've never attempted to weld aluminum but it must be about time to learn.
Think I've got some broken frame welds. I can feel the cart flexing and twisting under me and now it's snapped both the rear roof struts at the bolt holes where it attaches to the seat frame. I'm not surprised I mostly keep this poor thing in places it was never designed to go. I've never attempted to weld aluminum but it must be about time to learn.
Pulled the batteries today and found one broken cross member to frame weld. There could be more, one step at a time. Tried to weld the crack but couldn't find the aluminum welding kit I bought so I tried through the standard roller and liner. No joy had three birds nests in a matter of seconds from the word go.
Failed miserably trying to weld the crack. Ordered some different wire that should work.
Finally put the LifePO4 battery in today. Holy Smokes alive! Stupid quick is the only thought I can come up with for it. If you can imagine getting axel hop in a golf cart then you know what it feels like. Loosing 260-270 pounds and adding about 7 volts under full load really was a game changer. I'm actually a little afraid to mash it straight out anywhere it might get traction. Can not wait to get some taller SOFTER tires. It rides even rougher with the weight loss. Also looking forward to switching it over to a newer type system some time down the road. It would be nice to be able to run a lot slower without all the heat waste this one has. Went almost exactly 8 miles down logging roads and still had 71% state of charge when I got back. The new systems with regen motor braking would be a lot, maybe even twice as efficient as the current system.
Finally put the LifePO4 battery in today. Holy Smokes alive! Stupid quick is the only thought I can come up with for it. If you can imagine getting axel hop in a golf cart then you know what it feels like. Loosing 260-270 pounds and adding about 7 volts under full load really was a game changer. I'm actually a little afraid to mash it straight out anywhere it might get traction. Can not wait to get some taller SOFTER tires. It rides even rougher with the weight loss. Also looking forward to switching it over to a newer type system some time down the road. It would be nice to be able to run a lot slower without all the heat waste this one has. Went almost exactly 8 miles down logging roads and still had 71% state of charge when I got back. The new systems with regen motor braking would be a lot, maybe even twice as efficient as the current system.
Went to install a temperature gauge on the cart motor and found I had bent both rear leaf springs since switching the battery! Does anyone else know what can cause leaf springs to bend hard in front of the axel mount? To say the least I was surprised when I saw it. Last time I saw something similar the truck had over 1000hp and steam roller tires. I think maybe my little project could be making some torque. LMAO I'll post pics later to hot to walk back right now.
I see you have a spring-over lift block on stock springs. This will multiply the torque on the spring, especially if you have ever had to slam the brakes while rolling backwards. brake torque far exceeds motor torque. I'd replace the springs with some heavy-duty multi-leaf, or if stock, make some old school traction bars.
I'm 99.99% sure it happened when I had the axel hopping the day after I put the new battery in. Yes the lift does multiply the torque just like any lever does. I also thought of traction bars. I made the ones on my old racecar that went 8.73 @177mph but I think HD multi leaf pack springs will probably take care of it. If not there's always plan B.
So I just went out to check the current voltage and charge status. The only charge it's had today was from the solar roof and the battery is pretty much full. It's actually a little fuller than I'd like it for the longest possible battery life at 55.3 volts resting. I have the BMS programed to shut charging off at 56.8 which it had done. I may have to drop that a little lower. I'm not so worried about all the power I can get but I am trying to make this battery last as LONG as possible! That does seem to answer the question of if just one 300 watt panel in place of the roof can provide enough charge for my daily use. I didn't do a lot of extra running today but I did make the chore rounds and a few other things.
I am running a Renogy 300 watt 24 volt monocrystalline panel from 2018 and a Renogy 36/48 volt boost charge controller and a DIY 105AH 16s LifePO4 battery.
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