[encantotom]

When Tim Wade was here in my shop and we did the slide seal and other things he got me more interested in Lithium batteries.   he has a very powerful setup in his rig and does alot of dry camping.

so....i am experimenting slowly at first.   when tim was here we used my scissors lift.  the batteries were dead and bloated.   he said....why dont you do a lithium setup in the scissors lift.  so.....

even though many of you have played with them, i have not.  so i started researching.   there are places that sell lithp04  conversion kits for my genie gs1930.....they are 2k dollars.  

then you can buy cheap china 24v batteries.   on a slow boat and according to will prowse and others could be junk.  might not but could be.  

then i talked to jack haupt who evidently has converted everything he owns to lithium.   

then i ran across this fellow in the industrial area of old phoenix.   i went there and bought 3.2v calb ca100 100amp hour cells from him and a daly bms he happened to have.  

his name is trevor and he gurus username is higherwireinc   and his business is https://higherwire.com/     a very classy and smart guy.

i am playing with the scissors lift first and then will decide if i want to do anything with the newell.  trevor is more than willing to help in getting a coach set up with lithium.

the cells i bought were used in forklift batteries.   what i learned is that warehouses want 3 shifts of use from a single charge of an electric forklift.  it saves them time and allows them to have fewer forklifts.  when the battery pack (huge 48v) needs charging in less than 24 hours they immediately replace the pack.  trevor gets them and takes them apart to get at the individual cells, testes them and gets rid of the bad cells and then cells the good ones.  the cells i got from him had the amp hour, resistance and were charged to 3.2 volts.  

my scissors lift had 4 6v golf cart batteries in it.  in my very infrequent use they only last about 3 years.   and they are 500 bucks for the set if you find a good deal.  

they are 220 amp hour.   so if you use the rule of thumb that you get half the amp hours out of them, around a 100 lithium should be ok.  the new genielifts have 90 amp hour ones in them and the kits you buy are 105 amp hours.   i am starting with 100amp hour and have enough cells to do 200 if needed (but will be tight in the battery box)

there is a problem there though.....i am an EE.  so once i started getting into this....i ask too many questions and research too much.  and watch too much youtube and call to many of you guys....ha

so....feel free to contact trevor if you have questions.  he is a very interesting guy.

thats my 2 cents worth and i am sticking to it

tom

[BusNit]

The hardest thing in doing the conversion on the coach was finding and segregating the circuits of house/chassis/generator. I did not do a DC-DC charger and instead have a small Victron battery maintainer for the generator start batteries. I use the merge solenoid to bring all 4 batteries to a charge with the small solar charger every week or so. It just so happened that there was a receptacle on the driver side rear that the charger is plugged in to that's inverter driven. (generator start batteries are on that side)

[Richard]

Only one thing to modify about what you said. That 50% of nameplate is a rule of thumb for lead batteries. A better rule of thumb to use for LIPO is 90%

[Jack Houpe]

Tom I helped a friend convert his 45' Tiffin to solar with 400ah@48v of lithium. He followed our path with solar on the roof, 48v split phase inverter charger that supplies charge voltage to the lithium battery bank either from the sun, grid or both from there he has 2 victron mppt solar chargers that feed off the 48v lithium battery bank and charge his engine batteries and also his 12v house battery which are AGM batteries. The sun charges the 48v bank which charges his house battery and engine battery all the time, when he is plugged into the grid it still charges everything so his coach is live all the time no matter what just like our coach. We have yet to convert our coach to lithium because our AGM batteries were new when we bought the coach, soon as I see them depleting in AH I will build a big 48v lithium battery but will keep the engine and house batteries AGM. C (charge and discharge) rate on lithium is very high and if you hook a lithium battery to a standard alternator it will not last long. The best part of lithium is the normal cycles on lithium is around 5000 cycles and you can use 80% of the AH rating rather than 50% of a normal LA or AGM battery. Another positive for lithium is weight verse AH rating, they are lite in comparison. The negative is you cannot charge them which temps get to around 30F, they must be heated or you must have a BMS that can be programed to turn the system off when it gets cold.

[encantotom]

Thanks.  Richard I knew and met 50 percent for lead acid

I am playing with top balancing the batteries right now

Tom

[Gnawrocki1]

Tom,
I did the conversion with LifePo4 batteries just like yours to my scissors lift.  There is a few things you need to consider for machinery with hydraulic pumps.  

DC motors take a lot of juice to get rotating.  You will need to make sure that you have enough current capacity in your BMS so that you do not max out your current draw. Steady state you probably don't have an issue, but at start the current is huge.  I think my BMS is a JK brand with published 200A capacity, but if it hits 350A it will think it has a dead short even if it is for a very short time.  There is a little bit I can change in the software if I ran into problems, but it worked just fine on the scissors lift.

It worked so good I made a 12V Li battery for my dump trailer, and it would not start as it saw the start load as a dead short.  I had to go to JK's biggest BMS (300A) and then I was able to use keep the conversion.

The Lifepo4 batteries have no problem giving the start current, even though they are rated for 100A.  

If you need a crimper to make some cables, I can bring mine to your BBQ.  I might even have some lugs for the size you need.  I always buy too many as they are cheaper by the dozen!

Good luck

[Richard]

Tom,

That picture was worth a chuckle. I bought the exact same power supply from Amazon a couple of years ago to top balance my cells.

By the way, this summer will mark the 10th year the LiPo bank has been in our rig. Forest built it, and used it for 3 or 4 seasons. So the long life is not hear say.

[encantotom]

thanks glen, i have 2 sizes of hydraulic crimpers and lots of cable ends up to 4/0. i have a 250amp bms i put a clamp on amp meter on the lift before i took the old batteries out and the most i got was a peak of 150 amps. so i am hoping i am ok. i finished top balancing them this afternoon and made some rubber mats for the bottom of the battery tray which was pretty trashed from battery acid. i cleaned and painted it forst.

did you worry about weight and balance? the 4 old batteries weigh probably 200lbs and this 8 cell unit i built is probably 60lbs. not really any place to put any wight by the time i put the bms and victron charger in there.

tom

[Gnawrocki1]

I did not worry about the weight.  I saw that some commercial products add the weight, but as long as I don't overhang items off the lift, or go offroad too much, I should not have to worry.  The weight of the lift is significant, and the reduction of battery weight was not that much IMO.

[encantotom]

Was thinking the same. Gs1930 is 3200lbs and the old batteries are 250lbs. The new setup is about 60lbs

Thanks

Tom