91 replies to this topic

[muttmaster]

Not at all Vic. You have helped me so much in the past. From upgrading to heavy gauge cable from truck battery to installing Trimetric in my older camper, etc. you’ve been a great help. Convinced me to get a Victron 100/30 that should be in my mail today.

By the way. As many times as I have seen you recommending Victron, you must be getting a cut from them right? At least you should.

Just got a book “DIY Lithium Battery”, hope I learn something before my ebike arrives.

[Vic Harder]

Thanks... much appreciated.

 

No cut, no affiliation.  Nor with PKYS.com.  Both are excellent though.

[buckland]

Old Crow Thanks for that video. I have a DIY ebike (52V 20 Ah). I found the thread interesting as I too wanted to charge from Camper battery set up using a 1000 W inverter. I bought a second Battleborn (to be put in parallel). Hope this will work and will find out when the snow melts!  

[Old Crow]

 

Looking forward to seeing what you learn, buckland!

[Jack]

I will try. Getting many post on best way to juice up.

I watch few Utube video on DIY Lithium. 280 ah with four cells plus BMS for $500 or so China. What do you think? I like to just use battery charger provide by Radbike and even charge two battery over night. I will have plenty of ah left in the AM.
My two AGM in Grandby is five years old now, doing fine, but planning on getting more juice.

I went the DIY route. If you are comfortable with electricity, it's not particularly difficult. See https://www.wanderth...red/?hl=lifepo4

 

[muttmaster]

Thanks Jack for your DIY battery link! Awesome. I watched few Utube intro on builds and just got a book on DIY.

Did you get a Victron Smart Sensor. I understand that it can be set to turnoff charging at programmed temperature via Bluetooth. If that is that is the case, I won’t have to deal with heaters, etc. I camp in Winter a bit and don’t want cause damage charging at low temp.

Your battery cell ordered from Alibaba I assume? Vendor. I should read your DIY post first before asking.

[Jack]

I updated my build post with links to Alibaba and the other vendors: https://www.wanderth...red/?hl=lifepo4

 

The BMS has a temperature sensor that I wedged between two of the cells and the BMS will prevent charging below 32F. There's also a high temperature shutoff (113F?) but that won't be relevant in VT, at least for a while. You can change these limits in the BMS settings, and rando has a number of posts on charging at lower temperatures. Essentially, lower charge currents let you charge at lower temperatures. You can control the charge current in the Victron MPPT. The Victron DC-DC does not let you control charge current (but Victron says maybe in the future via an over the air update). If you disable the MPPT (via Bluetooth) and you charge only from the DC-DC, you are limited to a bit over 30A charge into a 280Ah battery. That's a charge level of about 0.1C - 10% of battery capacity. If the engine is not running, then the MPPT can charge no more than 30A or less if you change it via Bluetooth.

 

I have the Victron Smart Sensor. The Victron MPPT uses it to source the right voltage such that the voltage at the battery is the correct charge voltage. There is no "voltage drop" issue. Unfortunately, that is also a future upgrade to the Victron DC-DC.

 

[muttmaster]

Jack,
I bow before you. Thank so much. Just got notice that my Ebike is arriving on Monday! I thought I had a few weeks. I better place order today!

[muttmaster]

My new Ebike arrived yesterday, weeks earlier than initial delivery date. Maybe they had a fast boat from China. Did my first of three recommended balancing charge with 350 watts pure sine wave inverter. My first ride was to run down the battery level to about %25, and had no problem charging with stock 75ah AGM in the camper. I guess I worry too much.
I did order LifePo 200ah cells and will built battery to replace the aging AGM. Got a 800 watts inverter coming too as I anticipated charging two Ebike batteries at the same time.
Thanks all for your inputs and inspirations. I will continue to experiment with charging in the boonies and see how my system can handle my needs. I will update as I go along.

[buckland]

Thought I'd come back and ask more questions! As a reminder I converted my mountain bike to e-bike. It is wonderful. Attached is the battery and charger info. The battery is 52 V  11.6 AH  and the charger is 52V 3 Amp.    I have in parallel 2 Battle Born batteries for a total of 200 Ah. I have the 1000W Renogy pure Sine Wave 12V Inverter. The inverter is connected directly to the BB battery with heavy gauge 2 ft cables. ( the inverter in not independently grounded to camper frame other than through battery)

 

I ran the e-bike battery pretty close to empty and plugged in the charger to e-bike battery then plugged the charger to inverter then turned on the inverter.

 

Immediate chirp from inverter.... then it starts 15 seconds .... then the fan turns on as the 'fault' red-light comes on and the alarm and I believe it has stopped the charge. 

 

I immediately turn off inverter and wait... then retry with same results.

 

Charger works fine on 110V in garage.  I assumed (?!) the inverter could handle this load. My BB batteries are at 14.2 V 200 Ah.

 

What am I missing?

Attached Files

•  Screen Shot 2020-04-27 at 9.52.15 AM.png   212.75K   14 downloads
•  IMG_4208.jpg   84.67K   14 downloads

Edited by buckland, 26 September 2021 - 04:02 PM.