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What are you using for a balance monitor, and how is it connected? The self-powered meters may be rated for 48V, but the internal regulator might not handle the maximum 56 volts of a fully charged 4x12V lead-acid pack.
Hey Paul,What are you using for a balance monitor, and how is it connected? The self-powered meters may be rated for 48V, but the internal regulator might not handle the maximum 56 volts of a fully charged 4x12V lead-acid pack.
OopsMy question was for the previous poster: Miaplacidus82
I'm curious why go through all the hassle to monitor balance? Unless you are drawing over 500A all the time the pack will tend to remain in balance for several cycles. The electric motorcycle I recently build using an old dirt bike also utilizes the 2kwh Volt module. So long as you are monitoring full pack voltage - a 12S BMS has gotten so cheap these days that it seems silly to me to not use one - and the only time it needs to be used is during charging (which is how I charge my modules). My top speed is only 40mph or so, but with an 800A controller it will flip over backwards - attached a pic of the bike for fun. I'm curious also what range you are seeing with the 2kwh pack, I was thinking of getting mine registered for street use and changing sprockets to get 60mph.
Everything I have heard is that these Volt packs are extremely well matched (on many parameters) & very stable (as a whole).I can certainly understand the desire to be extra super careful! I personally haven't had any lithium batteries go up and I don't plan to! One thing I would like to suggest to you that I did before using legit BMS' is taking the standard BMS harness from the volt, and adapting a plug to it use with a hobbyking battery medic. I have one of these made for the 6S 1kw modules I use frequently, I can post a pic later. Link to a battery medic is here:
https://hobbyking.com/en_us/hobbykingtm-battery-medic-system-2s-6s.html
They are typically only used for RC vehicle sized batteries, but will also work with the Chevy Volt modules (balancing takes a lot longer). for the 12S module you simply need 2 of them, and you have a super super cheap way to monitor AND balance the pack all the time at an individual cell level! When I built my first electric vehicle with a 20S lithium pack I had an array of 4 of these (5S in each) mounted in front of me so I could see each cell all the time. It actually worked great!
Thanks for the compliments on the bike - I'm using a Motenergy ME1003 and Kelly KDZ72801E (regen version). Motor gets hot if you are riding through sand or mud but works great otherwise!