Search found 3386 matches

by Richo
Fri, 15 Feb 2019, 12:55
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

The flyback diode goes on the 12V side of the contactor. The controller should have motor protection on the HV side. Even less requirements to add something for 3-phase design. Normally it's not a TVS diode anyway. Just a rectifier diode pointing from -HV to +HV. Something like an APT60S20BG would p...
by Richo
Thu, 14 Feb 2019, 13:01
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

Ribfeast wrote:
Thu, 14 Feb 2019, 11:06
the Samsung SDI 20 profile is designed for a 16 cell LiFePO4 pack, so this is the likely path I will take.
Richo wrote:
Thu, 14 Feb 2019, 12:59
So LiFePO4 would be 15 cells. 48V nom. 54.7V charge.
So charging to 53V would loose almost nothing as a useable capacity.
Hmmm 15..16..
by Richo
Thu, 14 Feb 2019, 12:59
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

Looks like the Delta-Q 48V charger can put out up to 72V, question is how much voltage the lithium profile is set to (hoping around 53V). Not sure if the charger will let me run it without a battery attached to find out, and I'm not getting any response from their support which is frustrating... In...
by Richo
Wed, 13 Feb 2019, 12:41
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

I wasn't planning to mess with the Sevcon, plan was to pop in 15 or 16 LiFePO4 cells, Zeva BMS, Zeva screen, load new charge profile in Delta-Q and call it a day. Sounds like a fairly reasonable plan given all the options. Glad you pointed out the 57V controller limit, Don't forget these are user a...
by Richo
Tue, 12 Feb 2019, 13:03
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

So are you ditching the 12V LiFePO4 idea? Given we know now that your charger is adjustable. and the controller is adjustable (with programmer). and a BMS is likely... There is no need even to stay with LiFePO4. The only reason I suggested it was because this would have been a drop in replacement wi...
by Richo
Tue, 12 Feb 2019, 12:38
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

The CA100 has an internal resistance of <0.6mR.
So at 200A the loss/sag will be 0.12V.
or less than 2V for the whole pack.
by Richo
Mon, 11 Feb 2019, 14:45
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

$8,500 for one with new batteries.
https://www.truckworld.com.au/search/a~ ... =v~1-z~15-

The specs say it had a 500A controller.
Do you know what model of controller it has now?
by Richo
Mon, 11 Feb 2019, 12:44
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

Generally 12v lithium batteries with internal bms can't be put in series, unless rated to do so. The issue is they tend to use semiconductor based switching devices, which don't have much voltage headroom. True. But they would be referenced to the pack it's on. The issue will be when the BMS detect...
by Richo
Mon, 11 Feb 2019, 12:36
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

Actually the ev works 12V90Ah doesn't have internal BMS. They are matched cells. I don't see why these can't be serialised... How about a simple Zener+resistor overvoltage shunt? The controller should do the low voltage shutdown. A simple voltage gauge on each cell just to proove they are not out of...
by Richo
Fri, 08 Feb 2019, 13:17
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

I believe it has a Sevcon controller, and the motor would probably top out at around 200-300A if I was going flat out up a hill. The Trojans don't have a CCA rating and the max output claimed is <250A. So I'd suspect that they really were never up to the job anyway. The 48V sevcon controllers typic...
by Richo
Fri, 08 Feb 2019, 12:55
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

Sorry if it is borderline why bother with BMS or CAN? I'd keep everything the same/simple and go with a 12V block with the internal BMS. How many 3.2V cells should I get? 15 to make exactly 48V, or 16 cells to make 51.2V which is closer to what the lead acid pack would be? 15cells x 3.2V = 48V nom 1...
by Richo
Thu, 07 Feb 2019, 12:54
Forum: Technical and conversion discussion
Topic: Lead acid to lithium conversion
Replies: 37
Views: 416

Re: Lead acid to lithium conversion

For compatibility LiFePO4 is the better option Do you actually flatten it in one day/trip? The 12V packs have no BMS. https://www.evworks.com.au/winston-battery-lp12v90ah-lifepo4-cell-12v-90ah But the full pack would need to be about 48V 200Ah to be eqv. So $4-5k does sound about right. Obviously if...
by Richo
Thu, 31 Jan 2019, 12:50
Forum: Batteries, charging, management and monitoring
Topic: Battery Modules Questions.
Replies: 14
Views: 260

Re: Battery Modules Questions.

I am considering the possibility of making standard battery modules that I could sell to people doing EV conversions. Nice in theory but the market is nowhere big enough to make this profitable. Also I doubt one size fits all as there are too many different cars with different mounts and different ...
by Richo
Wed, 30 Jan 2019, 12:47
Forum: Technical and conversion discussion
Topic: Prelude conversion project - some questions
Replies: 162
Views: 11048

Re: Prelude conversion project - some questions

Alternatively I could find some closed cell foam and stick that down... EVA would work but would really need to be a continuous piece. So you would have to buy a big sheet just to cut a wired skinny shape o-ring. ~$20 for 2200x1100. I think Clark rubber used to have it on rolls you could buy the me...
by Richo
Tue, 29 Jan 2019, 12:08
Forum: The Lounge
Topic: Solar Panel output: Rating versus Reality
Replies: 38
Views: 1360

Re: Solar Panel output: Rating versus Reality

Well I'm curious to test this for myself.
I have a variety of panels brands+sizes I can check.
I don't have any semi-flex ones tho.
I'll have an ask around to see if I can borrow some for testing...
by Richo
Thu, 24 Jan 2019, 12:46
Forum: Other
Topic: YAEBU! (Yet Another Emax Battery Upgrade) project
Replies: 6
Views: 111

Re: YAEBU! (Yet Another Emax Battery Upgrade) project

10x 12.6V, 30Ah -"high power" Battery pack https://www.aliexpress.com/item/12V-30Ah-3S12P-11-1V-12-6V-High-power-Lithium-Battery-Pack-for-Inverter-Miner-Xenon/32923747867.html?spm=2114.search0604.3.1.2a69db83QDw7OU&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_10130_10547_319_317_10548_1069...
by Richo
Thu, 24 Jan 2019, 12:39
Forum: Other
Topic: YAEBU! (Yet Another Emax Battery Upgrade) project
Replies: 6
Views: 111

Re: YAEBU! (Yet Another Emax Battery Upgrade) project

I don't know about the e-max but the similar scooter I have does fit 8 Leaf cells with a bit of modifying.
8 x 7.6 = 60.8V nom
But they're a bit harder to get these days :(
by Richo
Wed, 23 Jan 2019, 12:54
Forum: The Lounge
Topic: Solar Panel output: Rating versus Reality
Replies: 38
Views: 1360

Re: Solar Panel output: Rating versus Reality

The sly trick the solar industry has used for ever is to not give true output figures in a real world application. Except the bit where they try to comply with international standards IEC 60904. Not surprisingly there are massive PV testing machines for IEC 60904. :shock: 1000W/m2 25DegC. In Austra...
by Richo
Fri, 18 Jan 2019, 12:38
Forum: The Lounge
Topic: Solar Panel output: Rating versus Reality
Replies: 38
Views: 1360

Re: Solar Panel output: Rating versus Reality

I know the percentage loss is for total power, not just the Vmp, so the math is vague at best, but you get the general idea. The graph for the 150W panel indicates the peak power output drops ~10% every 25DegC above 25DegC. On a clear sunny summer day in Australia if you can't take a panel from ins...
by Richo
Tue, 15 Jan 2019, 13:04
Forum: EV Racing
Topic: HP in EV vs HP in ICE
Replies: 10
Views: 562

Re: HP in EV vs HP in ICE

There may be some rules developed about how long the vehicle should run for. I can’t imagine an EV full of super caps that runs at well over the 2400hp of the V8, but can only accelerate for 10 seconds before needing a recharge would be considered in the spirit of the competition. At this stage I d...
by Richo
Mon, 14 Jan 2019, 13:01
Forum: Electric motors and controllers
Topic: Zero Turn Mower Conversion
Replies: 2
Views: 560

Re: Zero Turn Mower Conversion

Long time viewer first time poster?!?

Welcome John - even if it's 3 years late :D
by Richo
Mon, 14 Jan 2019, 12:59
Forum: Electric motors and controllers
Topic: Zero Turn Mower Conversion
Replies: 2
Views: 560

Re: Zero Turn Mower Conversion

21HP (15kW) obviously is not used continuously in reality. Otherwise for an hour mow you would use 15kWh of battery capacity. That's a modest $7,500 battery pack... It maybe easier to work out how much petrol you use for a mow and try to convert that into a battery capacity. This would also give you...
by Richo
Thu, 20 Dec 2018, 12:38
Forum: Batteries, charging, management and monitoring
Topic: ProLogium Solid State batteries (SSB)
Replies: 2
Views: 486

ProLogium Solid State batteries (SSB)

http://www.prologium.com.tw/NewsDetail.aspx?02F0EA87FB60FF52003AB70EAECFE03EC80757D9C75EC0110C4E14F09A3F397BCAF4F0A73BA67399F8B3A07F2CB48D31CE4F7B97FE3653973DE48FFC66B060AE82F045D252268314D157C3060DE8737493BCD1004C143314 Any hoo the next big thing to kick Musky's Giga-factory in the balls. {You are...