Goped ESR750 hoverboard convert to SLA battery.

Lightweight / Folding / Portable EVs - seats optional
BlitzKrieg   10 mW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by BlitzKrieg » Jun 30 2018 10:43am

I asked guys who really know what is going on with onboard charger and leds on the throttle lever.
As far as i know charger always use little more voltage because when charger is turned off the battery voltage is going down. So charger turned off when voltage is about 4.24 V on cell.

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fechter   100 GW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by fechter » Jun 30 2018 11:39am

That's probably OK, but still a little higher than most people want to go with a lithium battery. Charging to a slightly lower voltage (4.1v or 4.15v) will extend the life of the pack but sacrifice a little range.
"One test is worth a thousand opinions"

BlitzKrieg   10 mW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by BlitzKrieg » Jul 04 2018 3:27am

Charger use a higher voltage because when it will turn off battery voltage goes down about 0.2 V. After few hours Lix batteries can be charged again for some mAh.
Anyway guys who has hoverboard with lipo batteries by default tell me pls is it will stop to blinking when charges is complete or not?

BlitzKrieg   10 mW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by BlitzKrieg » Jul 11 2018 3:39pm

Hi guys.
Now i know how did the esr tell me that he is ready to ride. He bliknk with all his leds at the same time. And the voltage is 29.8
It is ok because when i turned it off the voltage will brings down for ~ 0.2
Thank you guys for helping me.

BlitzKrieg   10 mW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by BlitzKrieg » Jul 15 2018 6:47am

I ride 20.62 km and its voltage became 25.3. So i can ride more. I think it can be ~25 km. I dont try to ride far away, i was tired of his long ride and try to finish it as soon as possible.
But if i need to change this battery i will use 38140 LiFePo4 without balancer and i will use iCharger 3010b to charge it with balancer in 2p through 12 pin GX16-12, it is possible. It will be 24Ah with more current and lifetime. There is no any risk to use this battery without BMS because controller has the cutoff at low voltage for the LiPo batteries. Even if it will not cutoff at the right moment i can stop to riding when the last led will blink. But this battery is cheaper than LiIon and it has a longer lifetime. And i dont need to spend a lot of time to connect them into one pack. Its easy to assembly.

BlitzKrieg   10 mW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by BlitzKrieg » Jul 29 2018 3:05am

fechter wrote:
Jun 30 2018 11:39am
That's probably OK, but still a little higher than most people want to go with a lithium battery. Charging to a slightly lower voltage (4.1v or 4.15v) will extend the life of the pack but sacrifice a little range.
You are right. I have found that termination voltage on my iCharger 3010B for LiIo batteries is 4.10 V. So i should to charge pack to 28.7-29 V but not more. Onboard charger is estimated to charge LiPo batteries to 4.25 V per cell.
Is it possible to drop down highest voltage by modification of controller PCB (maybe i should to change one of the resistors or something else)? I can charge it with 3010b, or control the voltage by voltmeter, but it is more comfortable to charge it with onboard charger and did not think about anything.

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fechter   100 GW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by fechter » Jul 29 2018 1:08pm

Many chargers have an adjustment resistor inside. You might try opening the case and take a look. There are so many variations on these circuits it's hard to know without experience with that exact model.
"One test is worth a thousand opinions"

BlitzKrieg   10 mW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by BlitzKrieg » Jul 29 2018 11:22pm

There is variable resistor on the charger board. But it has a glue drop on rotatable part. And i have no idea how to regulate because i can't start charger without controller and can't measure its voltage without batteries connected. It starts only when batteries and controller are connected to it. It has 4 wires, two of them are used by controller to turn it on or off.

BlitzKrieg   10 mW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by BlitzKrieg » Jul 30 2018 2:24am

Its strange but... I have charged batteries with icharger 3010b to 28.7 V and now iam trying to charge it with onboard charger to 29.5 but charging process stops just after ~ 1 minute and voltage is the same 28.7.
Iam assumed that if i will turn onboard charger on it will charge batteries to its default cutoff voltage 29.5

BlitzKrieg   10 mW

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Re: Goped ESR750 hoverboard convert to SLA battery.

Post by BlitzKrieg » Jul 30 2018 10:07am

Damn BMS it turns off batteries when voltage became 23,0. 3.28 per cell. It is estimated for using with LiPo batteries and cutoff is to early.
Cutoff worked at 30 km trip.
The main problem is that i can't start charging it with icharger 3010b or with onboard charger. It doesn't start to charge. I used 24v power supply on external charger pins and only then BMS unlock cells and it was start charging.
The cutoff was very unpredictable, i didnt't expect it because the blinking third led was turning on only if power supply voltage was about 18V or more. At 15 V controller didn't start at all. So i assumed that i will stop to riding when the third led will start to blink. In my case it start to blink, i ride about 1 km and cutoff fired.
Maybe it will be better and easier to use LiFePo 38140 without any BMS because controller internal protection will save them at voltage more than 2V per cell. So BMS is not needed at all.

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