Charger with a screen?

[kmxtornado]

UPDATE
I will be using an inline watt meter between the charger and battery to get my numbers. Accidnwtally bought a 200a one but the wires were way way too big for my little wires. Will reorder.

The charger I bought is a metal case one, 5A. It replaces the stock plastic case one which I’m kinda worried would/could melt. I’ll just it as a backup when my new one comes in in mid November.

ORIGINAL POST
I'm been heavy into RC cars and FPV quads the past couple of years and enjoy being able to see and set the parameters for charging my batteries. It's a little unnerving for me to just plug an ebike battery into the wall using the charger it comes with and not know anything about what's going on other than waiting for a green light.

Do any of you charge your LiFePo4 batteries using some sort of hobby grade charger or charger with a screen that lets you set your own amperage and shows how many volts currently in the LiFePo4? I generally like to see voltage on each cell for 1-4S LiPo batteries. How does that work with LiFePo4? My hobby grade charger maxes out at 6S, but I'd need 16S for a 48v LifePo4. I imagine I'm not going to have a screen with any sort of charger that shows the voltages of each of the dozens of cells in there. Also there's no balance lead for me to be able to do that anyway (but maybe the BMS takes care of that?).

Wondering how you guys do it, if you do. Thanks.

 

[BVH]

I use the Grin Satiator. Completely programmable and 3 models available depending on what top Voltage you need. All chemistries can be charged but there is no individual cell Voltage display.

 

[kmxtornado]

I use the Grin Satiator. Completely programmable and 3 models available depending on what top Voltage you need. All chemistries can be charged but there is no individual cell Voltage display.

I was looking at that too, but out of my budget by a long shot. I don't have many other batteries to charge with this charger so may not worth it for me personally. Anything else you'd recommend? I'm ready for my stock charger to burn out and already looking for a quality replacement.

 

[electric_nz]

The ones from BMS battery show voltage and current, charge time, State of Charge on some sort of OLED display. Seem to be working of for me so far

 

[eMark]

THIS OPTION not for new Li-ion, LFP batteries, rather those with many discharge cycles ...

Have you ever left your battery charger plugged in for several hours (12-16hrs) once a month after the green light comes on? Try this 2-part trial test ...

If not at 4.20V adjust charger to 4.20V. Then as before unplug/disconnect charger after green light comes on. Take a test ride on level terrain at moderate speed. Record how many miles travelled when the readout goes from FULL (bar 5) to bar 4 ... continue riding until readout goes to bar 3 (again record mileage).

After 2 hr rest repeat charge, but this time leave charger plugged in for 12-16 hrs after green light comes on. Then do another identical test ride (same terrain and speed as before). Were you able to go 2-3 additional miles more before readout droped from 5 bars to 4 bars?

If above was helpful you may want to repeat this procedure once or twice a month depending on how many discharge cycles a month and condition of battery.

ANOTHER OPTION ...

You could also divide your 16S into four 4S using four 4S JST-XH balance leads and four Deans connector cables. The battery will still be 16S, but now you can read and balance the voltages of 1S-4S, 5S-8S, 9S-12S or 13S-16S (one at a time) using your 6S Hobby Charger.

Using these 4S connections you could also use your Hobby Charger (1S setting) to manually balance whatever individual p-group needs to be brought within your acceptable p-group voltage tolerance as shown below ...

I use the above to manually balance my 10S5P (either discharge or charge) using two JST-XH balance leads and two Deans cables (1S-5S) & 6S-10S).

ANOTHER OPTION ...

Divide your 16S into two 8S using two 8S JST-XH balance leads and one (or two) iSDT BG-8S BattGO balancers ...

https://www.amazon.com/Battery-Display-Digital-Capacity-Balancer/dp/B09BZJK2QB/ref=asc_df_B09BZJK2QB/?tag=hyprod-20&linkCode=df0&hvadid=532384528241&hvpos=&hvnetw=g&hvrand=13775670379279798477&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9019693&hvtargid=pla-1459676949257&psc=1

 

[jonyjoe303]

One solution for me is to use a LED volt/amp meter , they are inexpensive less then 10 dollars for the 10 amp model (they have up to 100 amp versions which require shunts) You would connect these between the charger and battery, and it shows the volts amps as they go into the battery. For the price these are very accurate, and have 2 screws in the back so you can calibrate the volts/amps if required.


Also available are the 90 volt 30 amp combometers (about 20 dollars) These don't require a shunt and read up to 30 amps. Very easy to hookup between the charger and battery.


All my chargers have these meters, I have to know exactly what the charger is doing and make sure the voltage doesnt go too high. And monitoring the amps you can tell how close you are to having a full battery, the amps go lower the closer you are to having a full battery. Very useful information.

As far as reading cell voltages, its easy for the smaller batteries (up to 6s) with available meters if the battery has balance connectors. But anything higher and you have to rely on the bms.

 

[kmxtornado]

I will need to rely on the BMS as there's no balance cable on the battery I'm purchasing. Thanks for the volt meter information. I'll look into that. That info is valuable (to me at least) indeed.

 

[amberwolf]

Do any of you charge your LiFePo4 batteries using some sort of hobby grade charger or charger with a screen that lets you set your own amperage and shows how many volts currently in the LiFePo4? I generally like to see voltage on each cell for 1-4S LiPo batteries. How does that work with LiFePo4? My hobby grade charger maxes out at 6S, but I'd need 16S for a 48v LifePo4. I imagine I'm not going to have a screen with any sort of charger that shows the voltages of each of the dozens of cells in there. Also there's no balance lead for me to be able to do that anyway (but maybe the BMS takes care of that?).

If you want to see individual cell-group voltages, you typically either have to:

-- add a balance connector (in addition to the one that's already built in that goes to the BMS) that lets you hook up external battery monitors or to use an RC charger that does this. (this means opening up the battery and soldering a whole additional wiring harness/connector onto the cells).

--or use a "smart" BMS that has a way to let this information be accessed by you--some use a bluetooth wireless connection to an app on your phone, some have a physical display you can wire up (or use BT to) to see this data. There's several good threads about various BT / smart BMS types with a lot of reports or data about various brands and models.

To use smaller RC chargers with a second balance connector, you'd need to wire up individual connectors for each RC charger you're using (so a 7pin connector for each 6s charger, plus the main leads if those are required to monitor voltages with, etc.) and the RC charger must be electrically isolated from input to output, so that they can't short across the cells when they're all hooked up together.

At least some of the smart BMSs can also have the cell-level trigger points programmed, such as LVC and HVC, and the balancing trigger points, and even overcurrent limits. Most of the batteries you run into won't come with anything like this; you'd probably have to buy such a BMS separately and replace the one that comes with your pack (but I expect that better battery builders like EM3EV and the like probably have the option to install one from the factory).

The problem with app-dependent devices is that unless you're one of the few that likes to lock down their phone / etc so it cannot autoupdate itself, the OS can update at any time to something the BMS app can't work on, and there is no guarantee the app will ever have any updates (even to fix massive problems it might have) to correct this. Alternately, the BMS app may autoupdate itself to a version with a massive problem that never gets fixed, or else takes away a feature you use all the time, etc.

So if you can buy a BMS that can use a hardware-based display, it could be more useful for longer (no way to predict this, since you don't know when or if any updates will ever happen, or if they will affect anything if they do).


If you want to program the charging current and voltage or other parameters of the charging profile of the charger itself, via an onboard screen, the choices are fairly limited; all the ones I know of are listed by other posters already (other than the RC chargers you're already familiar with).

There are quite a few "cheap" chargers that have a voltmeter and ammeter built in, and even some with knobs (or switches) that allow some variation in the voltage and current limit, but they're not "programmable" in the same sense.


You can add the ability to program the voltage and current limits, even charging timeouts, of a charger, by adding various external boards to them...but by the time you're done it's probably going to be a "project" and may cost as much as getting one with all the stuff built-in.

 

[BVH]

Here's a 16S programmable RC charger by ISDT relatively cheap. Read more about it but IIRC, you don't have to use the balancing function so at least you can specify your desired termination Voltage.

https://www.buddyrc.com/products/isdt-cm1620-modular-charger?variant=38076397027516

 

[kmxtornado]

I decided and went ahead and ordered an in-line watt meter to keep an eye on the status of the battery.

While I was at it, I ordered a second one for the scooter in my avatar. For that one, I'll probably use it as a live meter while I'm using the scooter. That one is a true scooter with no pedals so running out of juice mid-ride would be a bit difficult. Best to have stats on that. Although I've been trusting the throttle guess-a-meter the past 15+ years, maybe it's time to get more specific info so I'm not going through SLA's so much - particularly now when SLA battery prices have literally doubled! I remember getting 12v 9ah batteries for $20/apiece and now they're $40!