Anyone have this 100Ah Vestwoods battery?

[Texas-Mark]

Second battery capacity tested at 102Ah. I guess I will do the freezer test tonight to see if it actually has low temp cutoff.

 

[Texas-Mark]

Well, a bit of disappointment. I got the battery down to -3C per the app's ambient and PCB temps. Popped it on the charger for about 15 seconds and it never cut off.

The description says this:
"Built-in low-temp cut off prevents overcharging, only Interior cell is 32F/0C will be charged cut off by own."

Guess I will leave it in the freezer overnight and try again. Perhaps there is another temp probe buried farther inside.

 

[Texas-Mark]

After about 4 more hours in the freezer, the temp readings from the BMS said -14C and -13C and there was a status alert. The alert said 'Charging UT alarm' and the charging MOS status was open. So I guess it does have low temp cut off after all. I'm not sure at what reported ambient/PCB temp it tripped.

Edit: It took a while to reset the under temp (about 4 hours in room temp) and the ambient/PCB back up to 14C. I did not have to apply a charge or anything, it just reset on it's own.

 

[jimmu]

Thanks! I just ordered one for my RV.

 

[cs1234]

Does it appear to do any balancing of the cells, like their ad says it does? It says it "Support Balance Current".

 

[Texas-Mark]

Does it appear to do any balancing of the cells, like their ad says it does? It says it "Support Balance Current".

It "appears" to. I have my 4th one arriving tomorrow. Unfortunately the price just went up another $10 (on top of the previous $30)

 

[cs1234]

I found the app in the Android app store, it was in their amazon description somewhere.. Pow Bank

 

[jimmu]

It took 2 days to charge with a 100w suitcase panel and it triggered the Cell OV Severe Alarm. Is the BMS supposed to balance the cells from here?

 

[Texas-Mark]

Is the BMS supposed to balance the cells from here?

My third battery initially had more of a cell voltage spread than the other two, but seems to be getting closer to being balanced (on the fourth day of operation). So I do think it balances (slowly of course) over time. Since there are no BMS parameters to set in the app, I have no idea what cell voltage triggers the balancing.

Not sure if it matters or not, but I did not do a full capacity test on the third one, so it never got totally drained like the first two.

 

[cs1234]

I don't like the looks of those cell readings @jimmu , but I'm not an expert. Maybe somebody else with more lifepo4 cell voltage experience can chime in here. What charger and settings were you using with that panel?

 

[Texas-Mark]

I don't like the looks of those cell readings @jimmu , but I'm not an expert.

They are high. But he did say it went into over-voltage alarm. They should settle down after it sits for a while. He said he used a "suitcase panel" to charge it, so it may not have had a charge controller. Or at least not a good one.

 

[cs1234]

They are high. But he did say it went into over-voltage alarm. They should settle down after it sits for a while. He said he used a "suitcase panel" to charge it, so it may not have had a charge controller. Or at least not a good one.

It was cell 3 that alarmed me the most. That one is pretty far off the other 3 cells.

 

[Texas-Mark]

It was cell 3 that alarmed me the most. That one is pretty far off the other 3 cells.

Yes, but I think it is just because the other ones went so high (probably really fast) once it was going into over-voltage.

 

[cs1234]

I wonder what the voltages were before he started charging it. They are in series internally, so without some form of BMS balancing (which they say it has) they aren't going to balance out all by themselves unless he does what:

• Run it over and over again against the high voltage disconnect hoping that sad cell 3 comes up?
• Let it drain itself out completely, so they all start at a super low voltage?
• Maybe run a charger at a voltage low enough that the high ones won't bother taking any, but still at a high enough voltage to charge the undercharged one?

I have no idea what works to balance out the cells internally. I would like to know though.

 

[Texas-Mark]

As I noted above, I just let mine sit after being charged and once they got down to the resting voltage, they were pretty close. Then each cycle after, they got closer and closer. I think the biggest issue is that he charged it until it went into OV instead of just stopping at 14.4 or so.

 

[cs1234]

Hopefully he will keep us posted. Until Chins updates their plus battery with heating pads to have their new BMS with balancing, this Vestwood is on the short list for a 12v battery.

 

[Texas-Mark]

Yeah, I am happy with mine (I now have four). Wish the price had stayed down though.

I just picked up a Lachy 12V 100Ah for $239 shipped (Amazon with Vipon code). It has no Bluetooth or low temp cut-off (that I am aware of), and I still have to capacity test it, but it seemed like a half way decent price coming from US stock. I actually think it came out of the same warehouse as the Vestwood because they both shipped at the exact same time (ordered on different days), and came on the same truck (from CA).

 

[jimmu]

Its a Dokio suitcase panel with the cheap PWM charge controller. After day one the cells were pretty balanced. This is their current status after it sat overnight.

 

[Texas-Mark]

After a few cycles it will get closer. Just try not to overcharge it.

 

[cs1234]

Its a Dokio suitcase panel with the cheap PWM charge controller. After day one the cells were pretty balanced. This is their current status after it sat overnight.
View attachment 112095

Well, those numbers certainly look much better. Did you check what the voltages were when you first got it, before you charged it much?