looking for recommendations for BMS upgrade

Batteries, Chargers, and Battery Management Systems.
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zogthegreat
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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 19, 2017 1:26 pm

OK, I pre-tinned the leads and soldered them to the top, going one by one:

Image

Image

However... (sigh, why do I always have to use that word!), there seems to be a problem. When I hooked up the wires to the BMS, one of the lights is not working:

Image

I took a third look at the boards and the wiring seems to be correct:

Image

Image

The one thing of note is that the "red wire" went to B13 on the old board. It now goes to B13 - B16 on the new board. Did I mess up somewhere or is this correct?

BTW, if any thinks that they can repair my old board, PM me and I'll ship it to you. It has a blown out trace on it, but if you have the skills, I would rather give it away than toss it:

Image
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Re: looking for recommendations for BMS upgrade

Post by fechter » Dec 19, 2017 2:28 pm

Your new board might be OK. The lights only come on when the balancing shunts are active. Normally, there would be no lights on when the pack is in standby. Toward end of charge, there may be several lights on but not necessarily all of them. Check the cell voltage on the one with no light, it may be just out of balance enough so that one is lower than the others. The board balances very slowly, so if you have a low cell, it would be faster to individually charge that cell to bring it up with the others.

Your connections sound OK.
"One test is worth a thousand opinions"

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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 19, 2017 6:57 pm

How should I test? I measured complete pack voltage and I got 47.5v. I then measured terminal to terminal, walking down:

Image

and I got 3.6v on each. The math seems right, but when I hook the BMS back up, I still have a light out on #D16.

(EDIT) Just to mention, #'s D1, D2 and D3 also don't light up. These are the ones that are linked with D4 to the red connection.
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Re: looking for recommendations for BMS upgrade

Post by fechter » Dec 20, 2017 1:05 am

If you leave it connected long enough, all the lights should go out. At that point measure the individual cell voltages again.
It sounds like it's working correctly. The lights only come on when the cell voltages are higher than the set point.
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Re: looking for recommendations for BMS upgrade

Post by 999zip999 » Dec 21, 2017 12:35 am

How many watts is is battery rated for ? What amp limit can it be used at ?

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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 21, 2017 4:26 am

999zip999 wrote:
Dec 21, 2017 12:35 am
How many watts is is battery rated for ? What amp limit can it be used at ?
The battery is rated at 500w max, with a "Standard current - <15a" and "Max current: <30A(100us".

It's the same as this:

https://www.ebay.com/itm/DuraB-48V-12Ah ... SwJ4hY8kgS
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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 21, 2017 9:59 am

OK, so I finished wiring up everything last night. I put it out on my BBQ and plugged it in, (paranoia can be healthy at time! :wink: ), and left it for the night.

This morning the light on the charger was green and I started testing the packs and I got the following:

Image

The strange thing is that although the sum on the individual readings equals 57.1v, when I measure the entire pack, I get 53.9v. I have remeasured twice and I get the same results.
fechter wrote:
Dec 19, 2017 2:28 pm
Your new board might be OK. The lights only come on when the balancing shunts are active. Normally, there would be no lights on when the pack is in standby. Toward end of charge, there may be several lights on but not necessarily all of them. Check the cell voltage on the one with no light, it may be just out of balance enough so that one is lower than the others. The board balances very slowly, so if you have a low cell, it would be faster to individually charge that cell to bring it up with the others.

Your connections sound OK.
The lights have stayed on after charging. D1, D2, D3 and D16 have stayed off.

Image
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Re: looking for recommendations for BMS upgrade

Post by 999zip999 » Dec 21, 2017 10:46 am

Put a load onit dran it down a little and recharge. A light bulb will work.

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Re: looking for recommendations for BMS upgrade

Post by GalFisk » Dec 21, 2017 1:55 pm

Um... did you charge LiFePO4 to 4.1V per cell? That chemistry should not go above 3.65V per cell.

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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 21, 2017 6:51 pm

999zip999 wrote:
Dec 21, 2017 10:46 am
Put a load onit dran it down a little and recharge. A light bulb will work.
LOL, I only have 12v lights in my RV. I made a loop with a controller and a motor, then taped the throttle open about 15% to drain the battery. I'll take it down to about 50 - 51v and then try charging it again.
GalFisk wrote:
Dec 21, 2017 1:55 pm
Um... did you charge LiFePO4 to 4.1V per cell? That chemistry should not go above 3.65V per cell.
I'm using the charger that came with the batteries, so I'm assuming that it's the correct voltage for these batteries.
1st computer I used - Tandy TRS-80, 1st computer I owned - IBM PC-XT, 1st computer I fried - IBM XT-286

Pulse Charger Revolution, current stock w/ lead-acid batteries, (soon to change......)
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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 21, 2017 9:14 pm

So I drained the battery pack down to 50.5v and hooked it up to the charger. When it was finished charging, I remeasured and got the same results, cells 10, 11 and 12 showing 4.0v and all the rest showing 4.1v.

The BMS is also still showing red lights on D4 through D15, with D1, D2, D3 and D16 off.

Any suggestions?
1st computer I used - Tandy TRS-80, 1st computer I owned - IBM PC-XT, 1st computer I fried - IBM XT-286

Pulse Charger Revolution, current stock w/ lead-acid batteries, (soon to change......)
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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 21, 2017 9:36 pm

I went back to the sellers eBay page and reread the instructions and I noticed this:

Image

I don't have anything connected to the part that says "C- charge or discharge negative" "D- only as discharge negative". Is this where I should be connecting the charger? The original BMS was connected directly to the battery, so I went with what the original connections were. Did I make a noob mistake? Should I be connecting my charging neg to the C- charge or discharge negative"?

Here is the rest of the technical information:

"First 16 cells in series. If there are 32, you can be connected in parallel, and then series connection.
B-negative connection in accordance with the battery pack, followed by B1 + B2 + B3 + ... .. B14 + B15 + B16 +

The same interface:
Positive electrode of the battery pack is: charging and discharging of the positive electrode. C: it can be used as a negative charge and discharge of the negative electrode.

Sub-interfaces:
Positive electrode of the battery pack is: charging and discharging of the positive electrode.
C: it can be used as a negative charge. D: only as a negative electrode discharge.

Attention when connecting.

When we connect BMS with cells or disassemble BMS from battery pack, the following order and regulations must be complied with to avoid damage of components of BMS and problems of not protecting of cells.

-In order to achieve the best performance of BMS and to run the longest distance, all the battery must be matched well (Each battery voltage ≦0.05V, IR≦15 mΩ,capacity≦30mAh) to make sure the better consistency of the battery.

-Cell must be connected in parallel first, after then connected in series

-Order of connection:

Step1: Connect charging /discharging wire , battery pack negative wire

Step2:After confirm the wires are connected OK, plug the connector cable in the BMS

DO NOT plug CONNECTOR CABLE in the BMS before connect wire!!"
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Pulse Charger Revolution, current stock w/ lead-acid batteries, (soon to change......)
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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 21, 2017 9:53 pm

To answer my own question, yeah, I did do a dumb arsed noob mistake. I went back and checked the pictures I took before and I noticed that there were neg wires on the BMS go to the battery:

Image

I'm going to drain the pack down to about 46v, hopefully I didn't screw anything up. Is there anyone who can guide me through connecting the BMS properly?
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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 22, 2017 3:00 am

OK, I think I have this figured out:

Image

The positive from the charger goes to the battery positive, which loops back to B16 via the connector wires as per OEM's diagram. B16, B15, B14 and B13 connect to the battery positive. All of the other connections go to the battery in sequence.

The charger negative connects to the "C-" on the BMS. The B- on the BMS connects to the battery negative.

I haven't figured out "D-", I'm hoping that someone can enlighten me! ;)
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Re: looking for recommendations for BMS upgrade

Post by GalFisk » Dec 22, 2017 6:23 am

zogthegreat wrote:
Dec 21, 2017 6:51 pm
999zip999 wrote:
Dec 21, 2017 10:46 am
Put a load onit dran it down a little and recharge. A light bulb will work.
LOL, I only have 12v lights in my RV. I made a loop with a controller and a motor, then taped the throttle open about 15% to drain the battery. I'll take it down to about 50 - 51v and then try charging it again.
GalFisk wrote:
Dec 21, 2017 1:55 pm
Um... did you charge LiFePO4 to 4.1V per cell? That chemistry should not go above 3.65V per cell.
I'm using the charger that came with the batteries, so I'm assuming that it's the correct voltage for these batteries.
The seller avertised Li-ion but you got LiFePO4. The seller said 48V, but 13S LiFePO4 is 36V. The BMS was fried.
I think either this seller or the previous seller fried the thing with the wrong charger, and now you're doing it again.
LiFePO4 doesn't swell and catch fire when overcharged, but it still takes damage.

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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 22, 2017 8:57 am

GalFisk wrote:
Dec 22, 2017 6:23 am
The seller avertised Li-ion but you got LiFePO4. The seller said 48V, but 13S LiFePO4 is 36V. The BMS was fried.
I think either this seller or the previous seller fried the thing with the wrong charger, and now you're doing it again.
LiFePO4 doesn't swell and catch fire when overcharged, but it still takes damage.
Man I really want to use profanity right now! What do you think is my best course of action now? I'm a noob when it comes to lithium batteries, I've been using SLA's up to now.

The charger matches the charging port on the case. Here is the link to the battery on sun-ebike.com:

http://sun-ebike.com/48v12ah-li-ion-bat ... p0024.html

This is exactly what I have, but the strange thing is that sun-ebike list it as a Li-Ion but the battery has this printed on it:

HY11F14
104111E28
HPPN7070260 - 12AH

When I Google HPPN7070260, as you said, it comes up Lifepo4. I'm going to email sun-ebike but I'm really open to suggestions here.

(EDIT) They also have a 36v 12ah with the same case:

http://www.sun-ebike.com/36v12ah-li-ion ... p0025.html
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Re: looking for recommendations for BMS upgrade

Post by GalFisk » Dec 22, 2017 9:39 am

Start by discharging the cells down to 3.6V. This voltage is safe bor both Li-ion and LiFePO4. Then check with the manufacturer to see what you actually have got.
I don't know if it's possible to charge LiFePO4 to 4.1V cell voltage, or if the voltage is an indication that you have Li-ion after all. None of the Google hits on any of the numbers on the cells look particularly reliable, so they may yet be Li-ion.

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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Dec 22, 2017 11:50 am

OK, I drained the cells down to 3.6v ea and emailed sun-ebike. To further confuse the issue, I found the manufactures label on the battery case:

Image

It very clearly states that it's 48v 12ah. 48v 12ah 13S does make it a Li-Ion. Maybe the HPPN7070260 printed on the side was a manufacturing mistake. I'll wait for sun-ebike to get back to me. I think that they are in China, so it will probably be tonight. I asked if the sell replacement BMS's, which should have been my first step. Although the eBay ad states that the BMS is good for both Lifepo4 and Li-Ion:

https://www.ebay.com/itm/48V-16-cells-3 ... 2749.l2649

In one sense all of this is good. As I said, I've been using SLA's up until now. Even if I've managed to screw up the batteries, I have been learning a lot and considering that the pack "only" cost me $125.00, it make it a relatively inexpensive lesson considering how much a pack usually cost.
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Re: looking for recommendations for BMS upgrade

Post by GalFisk » Dec 29, 2017 11:00 am

Best of luck to you, hope the cells are fine.

The auction listing says lithium iron, which means LiFePO4 (Lithium Iron Phosphate). All voltages point to this (3.5V balancing, 2.0V LV cutoff, 48V 16S = 3V nominal per cell).

All rechargeable lithium batteries are really Li-ion batteries, but in order to group them we call those with the most common voltages (4.2V max, 3.6-3.7V nominal) for Li-ion, and those with other voltages by their respective chemistries.
Those that I know of are iron phosphate (LiFePO4), and titanate (Li2TiO3).

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Re: looking for recommendations for BMS upgrade

Post by amberwolf » Dec 29, 2017 2:15 pm

It could even be that the seller had a case laying around with a dead battery in it, and a battery without a case, so they shoved one into the other regardless of what the labels were, and then sold it as whatever they felt like at the time. It wouldn't be the first time someone posted about a pack that's completely different inside than what the ad said they were buying.

Money is money and some (probably many) sellers will sell anything without scruples.

Many sellers have no idea what the stuff they are selling even actually is; to them it's all the same. If it says something on the outside they'll sometimes use that to determine what to sell it as. If it doesn't, they may just make up information to sell it. If whoever they bought it from tells them it's one kind of thing, they'll probably use that info to sell it as that (and they don't know if it's right or wrong, and very likely don't care).


I'd recommend buying from trusted sellers (like Grin Tech) that will stand behind what they sell, but it's a lot more expensive for the same item (partly because they sometimes have to absorb the costs of batches of defective or mislabelled items; partly because they have to pay their support people and other staff, partly because they have to pay customs/etc on the items they import (where individuals often bypass that when buying from China/etc)).

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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Jan 11, 2018 10:52 pm

I hooked up everything according to the schematic that I made and all of the light come on now. :D :D

This just leaves "D-". On the original BMS, "D-" went to the key switch:

Image

It's hard to see on the picture, but the black lead from "D-" is spliced into the red wire going to the key switch. Since I'm planning to reuse the key switch with the battery, I'm going to connect it there unless someone thinks that's a bad idea. On the schematic provided by the seller it says "D-" is "only as discharge negative". I don't have enough experience with these batteries to know what that means.

Image
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Re: looking for recommendations for BMS upgrade

Post by amberwolf » Jan 12, 2018 2:20 am

zogthegreat wrote:
Jan 11, 2018 10:52 pm
On the schematic provided by the seller it says "D-" is "only as discharge negative". I don't have enough experience with these batteries to know what that means.
It means that if you use that to power the controller from, it will shut off power to the motor when the battery runs low (hits LVC), but that it doesnt' do anything to protect the battery if you tried charging thru it.

The C- (according to it's name) will protect both charge and discharge.

You'd use the charge/discharge (C-) to charge thru, regardless of which one (D- or C-) you run the controller from.

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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Jan 12, 2018 5:49 pm

Thanks amberwolf!

BTW, do you know where I can get some shrink wrap for the pack? I'm using packing tape right now, not sure how good that is for the long term! ;)
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Re: looking for recommendations for BMS upgrade

Post by amberwolf » Jan 13, 2018 1:11 am

maybe one of these has the info?
https://endless-sphere.com/forums/searc ... mit=Search

Whateer you use to wrap it with, first you want hard inflexible plates to cover the flat end cells, so they pressure evenly across the whole face.

If you don't, the wrapping bends the plates/etc inside the cells at the corners and edges, which can sometimes damage the cells electrically too.

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Re: looking for recommendations for BMS upgrade

Post by zogthegreat » Jan 13, 2018 1:50 pm

amberwolf wrote:
Jan 13, 2018 1:11 am
maybe one of these has the info?
https://endless-sphere.com/forums/searc ... mit=Search
Thanks! I guess I was using the wrong search phrases!
amberwolf wrote:
Jan 13, 2018 1:11 am
Whateer you use to wrap it with, first you want hard inflexible plates to cover the flat end cells, so they pressure evenly across the whole face.

If you don't, the wrapping bends the plates/etc inside the cells at the corners and edges, which can sometimes damage the cells electrically too.
:shock: :shock: Thanks for that bit of information! It's always the little details like that that end up nailing you! Fortunately, I kept all of the original packaging from when I disassembled the battery. I reused the yellow plastic sheets that the battery was originally wraped in to cover it up.

Image

I also used Dean's plugs for connecting the charging wires and the output. This way I don't have to do any more soldering on the battery, just cut my cables to length and plug right into the pack. The black tape is hockey stick tape. I really love that stuff, sticks much better than electrical tape. Up north, you can pick it up at any corner store.

Thanks to everyone for their assistance on this. It was a fun project and I learned a great deal.

:D :D :D :D
1st computer I used - Tandy TRS-80, 1st computer I owned - IBM PC-XT, 1st computer I fried - IBM XT-286

Pulse Charger Revolution, current stock w/ lead-acid batteries, (soon to change......)
Razor E300, modded with YK41B, Unite 36v 1000w, disc brakes

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