Echo 58v and Greenworks 60v in parallel

My original problem with my e-bike was with a fully-charged Greenworks 60v battery It will have +62v after charging, which is enough over-voltage to shut down the stock Bafang C961 display computer that controls the 48v BBS02 motor. Fortunately Bafang has built in over-voltage protection but I want to keep voltages at safe levels.

I recently added an Echo 58v battery and a marine dual battery switch into the mix. However I’ve been advised that combining batteries in parallel is acceptable if you prevent connecting into battery packs of significantly differing voltage. To address that issue, the marine dual battery switch allows for Battery 1 (Echo 58v), Battery 2(Greenworks 60v), Battery1/2 (parallel operation), and Off. I’m assuming 58v and 60v are not “significantly different”.
https://knightsucfedu39751-my.share...dAniKhePIUxakBMc_gnut2fJ8bLbs9S7482A?e=wX0ryc
When I switch to run in parallel, Battery 1/2 , my VOM shows 59v as it combines Echo 58 volts and Greenworks 60 volts in parallel. I’m thinking that if I run these two slightly-dissimilar batteries in parallel for a short time, the Greenworks voltage will drop down enough to the point where I can just switch over to Battery 2 operation only. That won’t cause any over-voltages into the Bafang C961 display unit.

Based on previous threads in the forum, Echo 58v 4ah batteries are: 14s2p 18650s

The Greenworks 60v 4 ah battery is Panasonic in a 6x5 array of cells. So I’m assuming it is 15s 2p (2 parallel blocks of 15 cells in series.). Numbers/letters stamped on internal cells is: Panasonic UIG95GD cells.

Would it damage batteries when using them in parallel for short periods of time? My only other option is to use a buck converter to keep Greenworks 60v down to a manageable level that will run the Bafang motor.

Greenworks and Echo batteries are the cheap way for me to power my e-bike but I need a 8ah pack to go any distance with pedal assist. So two 4ah packs seem to be a solution for me.

Ideally same exact model / type on both sides.

2V difference is certainly significant in any case.

The lower voltage bank will act as a load on the higher one, wasting precious stored energy.

The two banks will not feed the main load evenly, thus not wear / age evenly.

If the load draws the combination down below the resting V of the lower one, then maybe less an issue if they're only connected at those times, like with a momentary "turbo mode".

but optimum would be one large homogenous bank.

I only need to find the time for voltage drop of a fully-charged Greenworks 60v 4ah battery in parallel with the Echo 58v. I'm guessing it will only be a few minutes. From my personal experience, the Bafang C961 display computer will barely tolerate 61volts but anything more and it will shut down from internal protection circuitry.

I've invested in Greenworks 60v batteries because of my business but I didn't realize Echo was making 58v until recently. IMHO the Echo 58v battery is made to order for the 48v BBS02 motor. Price on ebay for either is much better than any e-bike battery I've seen, local buys available and on par with buying online. Decent rebuilts on ebay are <$100, my luck on using them at work has been good so far. Besides I'm not up the creek without a paddle if one pack goes down, just a little less amp-hours and pedal assist.

Echo and EGO both use 14 cells in series, regardless of the 56V / 58V names. They are both the same voltage for charging and also the Low Voltage Cutoff / LVC.

Greenworks uses 15S, and also...there is a 15-cell DeWalt pack that can be used as a 5S/3P in an 18V tool, or a 15S 1P in the other 60V tool. It's a clever design, but...exercise caution...

I've developed a healthy respect for 60v, battery building isn't for me.

So that's a reason why I gravitate towards these 2 brands, 58v Echo & 60v Greenworks. Lots of horsepower as long,as you don't exceed 61.5v feeding Bafang BBS02 motor and display/controller.

I've noticed with my new setup, dual batteries with selector switch, the 60v tends to run down faster than my 58v when I go into dual battery mode. I'm assuming 60v is charging 58v when in parallel. Does this seriously degrade the 60v battery? I need to run in dual mode for a few minutes to avoid overvoltages when fully charged Greenworks is plugged in and running.

Has anyone created a “receiver”, a 3D printable connector? Or how are others utilizing these?

Dewalt Flexvolt batteries are 20v/60v, 6ah on lower volts, so that is just 1/3 of amp-hours for my ebike needs. Price is typical for a 60v/2ah pack.

So as not to reinvent a wheel, I refer the reader to Ron/spinningmagnets, May 2017 article, who IMHO basically wrote the bible on the subject in electricbike.com, "Using cordless tool batteries for an ebike". Everything he's writing coincides with my previous year's experience, including the caveat on overvoltages with Bafang BBS02 and warnings on parallel operation, as he also mentions the need for a selector switch for this purpose as I have now done.

3d printing would be a market, I would consider buying adapters. I used aluminum brackets and some assorted metal clips pop-riveted in place. Low cost and high quality batteries are clearly within reach of ebikes with the packs for cordless power tools.

tomjasz said:

Has anyone created a “receiver”, a 3D printable connector? Or how are others utilizing these?

Click to expand...

I just ordered one of these for my Greenworks 60V
http://minne.us/grabpower/

Specifically this one:
http://minne.us/shop/80vadapter/

I confirmed with the seller that it should work on the 60V battery as well by sending measurements from my battery.

On the downside, I found it it probably won't work with my X1 Pro. The manufacturer said the controller is only rated for 14s. The 60V battery is 15s. It should work with my Sur Ron though... for a very short range spare battery!

I recently (Nov 2022) ordered a Greenworks 60v battery holder that was 3d printed by Jerry at minne.us. Very satisfied with final product. He advertises 80v Greenworks on his site but he can do 60v as well.

My current setup has a Ego 56v 5aH battery that runs parallel to a Greenworks 60v 4aH battery on my Bafang BBS02 bike. I need a way to drop a full Greenworks charge (typically 61,5v) down to something manageable that doesn't set off an over-voltage error on the Bafang controller. However I recently ordered an aftermarket battery on Amazon, a Jialitt 60V 5.0Ah Replacement Battery for Greenworks which doesn't fully charge to 61.5v, so it can be used as is, without needed to drop any excess voltage for the Bafang motor.

I'm also informed that Jerry at minne.us makes the Echo 56v battery adapter, which is the newer form factor replacing the old 58v Echo design.