Hello from North Wales

Richard Raine

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Nov 29, 2017
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2
Been having a good look around, as I have just begun my 18650 obsession.

I amprocessing about 150 laptop batteries and have so far yielded approximately 450 cells with charges above 2v, have about100 at less than 1v, which I may try to regen should time allow and also about 50 17760s why ch seem really solid so ma use these for small electronics projects, what have you guys been doing with these as you come across them whilst harvesting?

I am keen to start small and build a battery that will be the leisure battery on my VW Camper that will deliver me 240v via a small 12v inverter. Charging via the dyno would be a bonus, but I feel an alternator upgrade needs to happen first. How do 18650s get on with split charging units in vehicles?

I have been inspired by Jehu Garcia, EV West, HBPowerwalls etc... but am keen to understand the challenges our unique British weather bring to the party!

I have been scouting for UK subscribers so that I can follow your threads, is there any boards for UK DIYers?

Sorry for long post was supposed to be a quick Hello!

HELLO
 

daromer

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Oct 8, 2016
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Welcome!
Split charging?

You can have 1 or 10 chargers hooked in as long as they limits are correctly set. Ie max voltage and current and so forth. I have 4 chargers to my battery bank for instance.

Why not test all cells directly? Unless you are in time constraint i suggest to test them all. The voltage of the cell is not the thruth about their state :p
 

cristof

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Sep 30, 2017
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Croeso
Welcom,
Bienvenue
 

Richard Raine

New member
Joined
Nov 29, 2017
Messages
2
daromer said:
Welcome!
Split charging?

You can have 1 or 10 chargers hooked in as long as they limits are correctly set. Ie max voltage and current and so forth. I have 4 chargers to my battery bank for instance.

Why not test all cells directly? Unless you are in time constraint i suggest to test them all. The voltage of the cell is not the thruth about their state :p
Hi daromer

I meant in the vehicle there are systems which split charge from the alternator to two batteries usually both Lead Acid, wondered if anyone had a 18650 battery in this configuration.

I am going to test all cells but am in the first charge -check for self dischargephase and have just finished all my discovered +3v cells now moving onto my +2v pile and will likely start capacity testing before do8ng the more time consuming 0 - 2v set.
 

daromer

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It wont work to paralell a Lead acid battery at 12v with a Lithium battery out of the box as such. I would build 2 systems where you can divert energy from the main battery and generator from the car to the Lithium bank powering the RV itself. I did post links and stuff the other day on Facebook. Dont find the post but this charger could work
 
Joined
Oct 21, 2017
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Hi Richard

Im massively regretting selling my 1959 beetle! Would have made an awesome EV and Thats 100% what I would be doing right now if I still had it!

So its complicated using Lithium packs as your probably going to try the easiest method in your camper usingbattery to battery charging as your asking about split charging.

3s 18650 packwill give you if you(taking on board the amazing advice from others :)) an operating voltage of 12.3v(4.1v Charged)-9v(3v Discharge).

If your thinking of using a quality inverter like a pure sine 2000w since its a camper the inverter minimuminput is10v.

You can program the input voltage range from 10v-15v soprogram for 10v to give you maximum range but that said you only discharging to 3.33v Im not sure if that has any other impact other than cutting out earlier than the battery could last.

Build your capacity big this could work.

With VSR's im not sure how you would control the current so you may need additional parts to step down otherwise with the VSR link aboveyou need to build 3s140p to charge at 1A. This would use420 cells, if you had 2200mAh from your cells your talking 308Ah and 3kWh Pack from recycled batteries.

Car lead acid batteries full charged are anywhere from 13.7 to 14.8 but that VSR passes dc across at 13.7v. This is where some of the other guys expertise is going to be better than mine to whether a step down/buck converter would be needed to bring the voltage down to 12.3v for charging and how this effects the current?

I believe the alternator on old vw's you dont see no more than around 14.8-15v tops which probably rules out 4s design as you never charge the cells more than 3.75Vs using a rectifier.

Its easier forJehu Garcia as his whole bus is EV and running on Lithium! Yours from the sounds of it isstill aircooled and hopefully 12v not 6v ;)

Hope this helps some how! Would be good if some of the extremely technical guys on here could point you in the right direction for parts as 18650 packs are so much smaller than traditional leisure batteries. I would consider a PV panel too dude for when your camping!
 
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