Chargery: AH measurements

[Cal]

Small question: is there a datasheet of some sort for the BMS?

BMS8T

 

[Bob B]

I think it would be necessary to have a LVD regardless of how accurate the coulomb counter is.
It's the same as relying on an inverter or charger to cut off when the pack is full or empty. The BMS knows the individual cell voltages and a cell voltage can easily be out of whack even when the pack voltage or coulombs is not.

 

[Craig]

Say what?

Not standing on any "high horse"

Just presented the facts on Chargery current measurement and AH calculations.

I get the feeling YOU, as a seller of Chargery hardware, sound a bit disgrumpled.

Don't shoot the messenger!

I have made it clear time and time again that these things leave a little to be desired. But also I have also found them to do what I need them to do at a reasonable price.

What irritated me is you said you knew how to take care of batteries. I'm sure that's true but why wouldn't you check the voltage now and then?
I have stocked Chargeries for the convenience of forum members. But if people wish to keep denefrating them because they think they are something they are not. I will quit sekki g them here at cost and you all can buy them k. Ebay for 25 to 30 bucks more.

 

[Craig]

Let me make this clear. I recommend chargery for a few reasons.
1. It reports voltage values of each cell in a pack.
2. It will turn off charging / discharging if any cells get too far out of whack.
3. It will turn off charging if pack voltage is too high or low.
4. It is way configurable so you can Taylor make it to your needs.

5. It can handle more amps than any other device I know of.

I do not use it to count the exact Ah remaining in my battery.
I do not use the shunt at all for that matter.

Sorry if I come of defensive I don't care about the chargeries weather or not anybody buys one. I do care that someone questions my motives.

 

[Bob B]

I agree with craig on this one ..... I have known about the SOC deficiencies in the Charger for some time now .... but still intend to use it because of all the other things it does that I want it to do ... and it seem reliable at doing the protections I want.

Now .... if I had known this BEFORE I bought the Chargery would I have still purchased it .... probably. The only other BMS that I have seen that doesn't break the bank and has similar functionality is the Electrodaucus and the strategies recommended by the developer kinda make my head spin.

 

[Cal]

What irritated me is you said you knew how to take care of batteries. I'm sure that's true but why wouldn't you check the voltage now and then?

My batteries are not issue. Please don't make it the issue. I regret I mentioned them. However you seem to see it as carelessness on my behalf and want to jump on it. You have also made it personal. Bait and switch?

 

[BiduleOhm]

BMS8T

Thanks

I read all of it and can't find any mention of the 1 A minimum, nor any spec for the current measurement accuracy.

So yeah, you can't have guessed that.

I agree with craig on this one ..... I have known about the SOC deficiencies in the Charger for some time now .... but still intend to use it because of all the other things it does that I want it to do ... and it seem reliable at doing the protections I want.

Now .... if I had known this BEFORE I bought the Chargery would I have still purchased it .... probably. The only other BMS that I have seen that doesn't break the bank and has similar functionality is the Electrodaucus and the strategies recommended by the developer kinda make my head spin.

The problem isn't that the BMS is doing that (well it kind of is for some people), is that there's no mention at all of this behaviour. So you buy it and expect it to work normally and not have this weird thing. If it was mentionned then you can make an informed choice and still buy it, or not buy it.

 

[Craig]

My batteries are not issue. Please don't make it the issue. I regret I mentioned them. However you seem to see it as carelessness on my behalf and want to jump on it. You have also made it personal. Bait and switch?

All I asked is if the LVD didn't work. Then you got defensive and stared you knew how to take care of batteries. I was wondering if there were another issue. No bait and switch here.

 

[Bob B]

The problem isn't that the BMS is doing that (well it kind of is for some people), is that there's no mention at all of this behaviour. So you buy it and expect it to work normally and not have this weird thing. If it was mentionned then you can make an informed choice and still buy it, or not buy it.

I agree ... That is the reason I have posted my experience with Chargery SOC inaccuracies in a couple different threads. People need to be making informed purchases.

A couple other observations .... I wish that Jason would post his response to this on the forum instead of sending an email to CAL .... but I also wish that CAL had gotten his permission before posting the private email. I understand his frustration with the situation and he is even trying to build his own coulomb counter.

I think the inaccuracies with the cell voltage readings some people are having is a worse problem than the SOC problem. A VERY big part of a BMS function is to provide cell level protections ... those cell level protections and balancing functions are based on cell voltages. (I don't have a problem with cell voltage readings with my BMS8T)


I moved on from the SOC shortfall .... just decided to deal with it a different way. That doesn't mean I am happy with having to buy other equipment in order to get good SOC tracking.

 

[Craig]

My batteries are not issue. Please don't make it the issue. I regret I mentioned them. However you seem to see it as carelessness on my behalf and want to jump on it. You have also made it personal. Bait and switch?

I have made it personal when you started attacking my character.

 

[Craig]

I agree ... That is the reason I have posted my experience with Chargery SOC inaccuracies in a couple different threads. People need to be making informed purchases.

A couple other observations .... I wish that Jason would post his response to this on the forum instead of sending an email to CAL .... but I also wish that CAL had gotten his permission before posting the private email. I understand his frustration with the situation and he is even trying to build his own coulomb counter.

I think the inaccuracies with the cell voltage readings some people are having is a worse problem than the SOC problem. A VERY big part of a BMS function is to provide cell level protections ... those cell level protections and balancing functions are based on cell voltages. (I don't have a problem with cell voltage readings with my BMS8T)


I moved on from the SOC shortfall .... just decided to deal with it a different way. That doesn't mean I am happy with having to buy other equipment in order to get good SOC tracking. With my BMS8T, I don't have a problem with cell voltage readings.

Yes cell inaccuracies are not acceptable. The issue should be resolved by Chargery or the vendor without any cost to the buyer. I have already exchanged 1 or 2 that I sold.

 

[Cal]

I have made it personal when you started attacking my character.

No, it started with the high horse comment.

 

[Cal]

A couple other observations .... I wish that Jason would post his response to this on the forum instead of sending an email to CAL .... but I also wish that CAL had gotten his permission before posting the private email. I understand his frustration with the situation and he is even trying to build his own coulomb counter.

Please don't comment on something you have no knowledge of. I certainly did ask Jason if his message could be posted.

 

[Craig]

No, it started with the high horse comment.

You are correct. I was trying to help and you said you knew what you were doing. Good luck.

 

[Cal]

Hey, it's no fault but my own what happened to the battery. Never blamed Chargery that the battery discharged to zero volt. I did mention the SOC display is a disaster though. I'll stand by that.

 

[Craig]

Hey, it's no fault but my own what happened to the battery. Never blamed Chargery that the battery discharged to zero volt. I did mention the SOC display is a disaster though. I'll stand by that.

I agree it leaves some to be desired. I have never used the shunt. I use it by going by voltage alone and it seems to be about right but then I have never actually compared it to anything else.

 

[Bob B]

Please don't comment on something you have no knowledge of. I certainly did ask Jason if his message could be posted.

When you posted Jason's email content ... you said that you HOPED it was OK with him that you were posting it. If you asked for his consent, I would have thought you would have said that instead.
If you asked for his consent ... I am fine with posting it.

 

[Cal]

I asked him but he didn't reply.

 

[Bob B]

I asked him but he didn't reply.

I personally would have interpreted that as a no .... but I may be a little more sensitive about not repeating something you are told in confidence than most.

 

[eumobong]

Timely thread.
My take:
-Use a victron bmv for soc and AH measurement.
-Use chargery or any other bms

My initial plan was to discard my victron bmv but with this result Ihave to think twice. I wasted my time editing a python script to get this data to MQtt server for automation. Chargery disappoints me with this. SoC is a very important parameter and without it, it's just like any other cheap Chinese bms (except for ability to handle high charge current - do I really need that?)