Roypow Lithium Review

[Nolagt]

Originally Posted by Haddixbros

I will inevitably total the cart by doing burn outs and wheelies

[fstop]

Originally Posted by Haddixbros

just wanted to give an update on the battery pack: it has performed well given the price point. There seems to be a difference in performance set by the BMS when the battery is freshly charged vs. when it has sat for a week without charging. There were also a couple of times where the BMS would shut off the battery due to over amp draw (I have some heavy friends that I like to pop wheelies with). This was just occasional and was easily fixed by disconnecting the battery terminal/lead and turning the battery back on.

For $1500, I cannot imagine a better deal. this battery will surely last longer than the cart will, as I will inevitably total the cart by doing burn outs and wheelies

My observation is that between the BMS itself drawing minimal current and the controller's base current draw, sitting for a week pulls more out of the battery than you might think - or at least mine does.

On the other hand, I've noticed that if you turn the battery itself off, even for a week or two, it seems to be right where it was in terms of charge state / voltage level without any drain from the cart or the BMS (or at least less from the BMS - not sure if it is ever really "off" - they are unclear on that).

Glad it is continuing to do what you want it to do - thanks for the report.

[ecpchris]

Anyone have an update on the “P” model release of the roypows? They told me October but when I followed up, haven’t received a response.

[sowilliams]

I read in here somewhere that you shouldn't charge the Roypow daily but is there a rule of thumb on when you should charge them? Should you run them down to a certain level before charging? Thanks!

[Lightning8U]

Originally Posted by sowilliams

I read in here somewhere that you shouldn't charge the Roypow daily but is there a rule of thumb on when you should charge them? Should you run them down to a certain level before charging? Thanks!

I've been told by RoyPow that is doesn't matter but to keep charge cycle counts down, which is tracked with the BMS, I only charge when it gets down to 2-4 bars remaining. The warranty is 5 years, I am not sure if they will honor a warranty passed the 3,500 charge cycles...

[fstop]

Originally Posted by Lightning8U

I've been told by RoyPow that is doesn't matter but to keep charge cycle counts down, which is tracked with the BMS, I only charge when it gets down to 2-4 bars remaining. The warranty is 5 years, I am not sure if they will honor a warranty passed the 3,500 charge cycles...

I have no idea if the BMS actually keeps track of anything, but charge cycle from the battery's perspective can be partial though, to the best of my understanding.

In other words, if you are at 80% and charge until full (or are at 100% and use the cart until 80%) that is 20% of a cycle.

So as far as I know, from that standpoint it doesn't matter if you charge 3 times from 80% to full, or charge 1 time from 40% to full. The battery sees similar "wear" - about 60% of a single cycle.

That said, I think it would be best to keep above 20% and not charge above 90% unless you need the range, but in my RoyPow testing "100%" isn't full cell voltage, and when you reach zero bars it still isn't at minimum cell voltage either, indicating (like cell phones and other items) that the manufacturer has already taken more ideal conditions into account to some degree. RoyPow supplies its chargers, so allows them to set the max. charge in this way. The SOC meter will show 100%, but in theory those batteries could take a slightly higher charge but it isn't much and the headroom they leave there helps make the battery more bulletproof regardless of how you charge it.

I usually only charge all the way if I know I'm going to use it soon after, and whatever charge is in there may be below some certain level.

I accomplish this with home automation, by issuing a voice command to "charge the cart for x hours", since (with my RoyPow anyway) 1 hour of charging is exactly 2 bars on the SOC meter and you can see quickly how many hours you want it to run. It turns off the charger after that time. If I don't include the "for x hours" it just charges for 5 hours then turns off.

[Bama Brad]

Originally Posted by Lightning8U

I've been told by RoyPow that is doesn't matter but to keep charge cycle counts down, which is tracked with the BMS, I only charge when it gets down to 2-4 bars remaining. The warranty is 5 years, I am not sure if they will honor a warranty passed the 3,500 charge cycles...

I do the same thing, I did charge it at about 7 bars once and it still took about 3 hours to complete the charge, so I wait until about 3 bars before putting on charge. Seems to run just as good at 3 bars as it does at 10 bars, so I just wait until it gets low.

[Lightning8U]

Originally Posted by fstop

I have no idea if the BMS actually keeps track of anything, but charge cycle from the battery's perspective can be partial though, to the best of my understanding.

In other words, if you are at 80% and charge until full (or are at 100% and use the cart until 80%) that is 20% of a cycle.

So as far as I know, from that standpoint it doesn't matter if you charge 3 times from 80% to full, or charge 1 time from 40% to full. The battery sees similar "wear" - about 60% of a single cycle.

That said, I think it would be best to keep above 20% and not charge above 90% unless you need the range, but in my RoyPow testing "100%" isn't full cell voltage, and when you reach zero bars it still isn't at minimum cell voltage either, indicating (like cell phones and other items) that the manufacturer has already taken more ideal conditions into account to some degree. RoyPow supplies its chargers, so allows them to set the max. charge in this way. The SOC meter will show 100%, but in theory those batteries could take a slightly higher charge but it isn't much and the headroom they leave there helps make the battery more bulletproof regardless of how you charge it.

I usually only charge all the way if I know I'm going to use it soon after, and whatever charge is in there may be below some certain level.

I accomplish this with home automation, by issuing a voice command to "charge the cart for x hours", since (with my RoyPow anyway) 1 hour of charging is exactly 2 bars on the SOC meter and you can see quickly how many hours you want it to run. It turns off the charger after that time. If I don't include the "for x hours" it just charges for 5 hours then turns off.

Fstop, great reply! Your instinct is correct. According to RoyPow engineers, When the SOC meter shows 'full' or 10 bars, the actual charge of the cells is at 91% of total battery capacity. Similarly, when the pack shows 'empty' or zero bars (at which point the pack will actually shut itself off to prevent permanent degradation of the cells) the reserve capacity in the cells is approximately 20%. So the 10 bars on the SOC meter is showing the usable charge between 20 to 91%. RoyPow did a great job engineering the BMS here to 'idiot-proof' the battery packs.

THe RoyPow has automated the battery care that Tesla urges its customers to observe. "Don't charge beyond 80-90% unless you absolutely NEED the full range of the pack, and try to never discharge the pack below 20%."

Hope this helps! There is no harm in running the packs down to 1-2 bars on the SOC meter as the reserve capacity in the cells is already programmed with an artificial safety floor.

[Nolagt]

Originally Posted by Lightning8U

Fstop, great reply! Your instinct is correct. According to RoyPow engineers, When the SOC meter shows 'full' or 10 bars, the actual charge of the cells is at 91% of total battery capacity. Similarly, when the pack shows 'empty' or zero bars (at which point the pack will actually shut itself off to prevent permanent degradation of the cells) the reserve capacity in the cells is approximately 20%. So the 10 bars on the SOC meter is showing the usable charge between 20 to 91%. RoyPow did a great job engineering the BMS here to 'idiot-proof' the battery packs.

THe RoyPow has automated the battery care that Tesla urges its customers to observe. "Don't charge beyond 80-90% unless you absolutely NEED the full range of the pack, and try to never discharge the pack below 20%."

Hope this helps! There is no harm in running the packs down to 1-2 bars on the SOC meter as the reserve capacity in the cells is already programmed with an artificial safety floor.

Tell them to get that P packs state side stat lol.

[Lightning8U]

Originally Posted by Nolagt

Tell them to get that P packs state side stat lol.

Believe me, I am trying!!!