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Tech => Parts, Mods And Hacks => Topic started by: Psycopyro on August 12, 2017, 08:16:11 PM

Title: Questions on batteries and chargers
Post by: Psycopyro on August 12, 2017, 08:16:11 PM
Hi e-riders!

I'm new with that technology and after reading many topics on forum, I have some questions, probably already answered, but cannot find the right google-keywords...

For my understanding, li-io battery shall be charged with a constant current until it reached the max voltage of cells then constant voltage until amp reach a minimum value (nearly 0?).

Cells aren't identical, some reaches the voltage first, but the average or sum of pack didn't reach the value. I read that cells can be protected with electronics on each cells, or sometimes a BMS can handle that.

1. Some people use PSU Server to charge their batteries. I see some used PSU quite cheap (ex: Cisco WS-CAC-3000W or 6000W). Is the PSU has to have specific function as limit current on the first phase, adjustable max voltage? Is maximum watt delivered by PSU defined the XC charge?

2. For example, in a Tesla Battery modules or in a Zero Battery modules, are cells self protected or all cells are monitored by a BMS or just natural balacing?

Thanks

Title: Re: Questions on batteries and chargers
Post by: togo on August 13, 2017, 12:24:57 PM
There's a bms, and it controls balance and protection of the cells.

Some have made DC supplies charge their motorcycles. They are not meant for a vibrating environment or moisture or dust, but there are success stories. In my experience people don't talk about their own failures as much. Anyway, search the forums for meanwells.etc and you'll find a lot of discussion.
Title: Re: Questions on batteries and chargers
Post by: Ndm on August 15, 2017, 12:22:21 AM
I can tell you about a failure, I bought two meanwell 3000/48 power supplies, I have not had a problem with the supplies but they are big and heavy and take up valuable real estate on the bike, anyway I made it about 100kms from home and found out that the diodes I bought off eBay were not up to the task of charging for a long period and they smoked , I was able to charge off the plug next to the evse, but sat around for four hours, I then bought the ThunderStruck Motors TSM 2500 and paid almost the same (not including labour) but haven't had a problem yet, the meanwells are for sale ::)
Title: Re: Questions on batteries and chargers
Post by: firepower on August 15, 2017, 05:07:18 AM
Or you could have bought the correct diodes rated for the task :D
Title: Re: Questions on batteries and chargers
Post by: MrDude_1 on August 15, 2017, 05:52:49 AM
I can tell you about a failure, I bought two meanwell 3000/48 power supplies, I have not had a problem with the supplies but they are big and heavy and take up valuable real estate on the bike, anyway I made it about 100kms from home and found out that the diodes I bought off eBay were not up to the task of charging for a long period and they smoked , I was able to charge off the plug next to the evse, but sat around for four hours, I then bought the ThunderStruck Motors TSM 2500 and paid almost the same (not including labour) but haven't had a problem yet, the meanwells are for sale ::)

If you're charging through the diodes, you're doing it wrong.
Title: Re: Questions on batteries and chargers
Post by: Ndm on August 15, 2017, 05:01:06 PM
I was charging through the diodes (in between the two supplies), I was mainly trying to make the point that if you don't know exactly what you are doing and can't design a fool proof solution you are better to leave it to the right people, ie diginow/ThunderStruck, I've since learned the errors of my ways after follow up research :-[
Title: Re: Questions on batteries and chargers
Post by: MrDude_1 on August 15, 2017, 06:17:04 PM
I was charging through the diodes (in between the two supplies), I was mainly trying to make the point that if you don't know exactly what you are doing and can't design a fool proof solution you are better to leave it to the right people, ie diginow/ThunderStruck, I've since learned the errors of my ways after follow up research :-[

or be willing to learn.
the diodes should be back-biased across the supplies, not between them.
there should be no power going through the diodes unless there is a problem with one of the chargers.
Title: Re: Questions on batteries and chargers
Post by: Psycopyro on August 15, 2017, 06:51:42 PM
You are correct meanwell vs third party equipement, cost saving seems tight.

Actually I try to evaluate cost of a DIY motorbike for a race track, so the charger dont have to be water/dust/vibration proof.

A power supply as I quoted can be founded for less than 80€.

With a limited power, selected to limit the maximum current of battery spec, it will perform a constant power then constant voltage charger.
Title: Re: Questions on batteries and chargers
Post by: Ndm on August 16, 2017, 01:18:18 AM
I think that if you are confident in your skills you can make it work, as for me I gave up on the power supply route due to water/dust/vibration/ size/weight , and yes mrdude I learned that with my follow up, failure is a wonderful teacher (if not sometimes an expensive one)
Title: Re: Questions on batteries and chargers
Post by: clay.leihy on August 16, 2017, 06:46:35 AM
I think that if you are confident in your skills you can make it work, as for me I gave up on the power supply route due to water/dust/vibration/ size/weight , and yes mrdude I learned that with my follow up, failure is a wonderful teacher (if not sometimes an expensive one)
As the Mythbusters used to say, "Failure is ALWAYS an option."

Sent from my Z981 using Tapatalk

Title: Re: Questions on batteries and chargers
Post by: BrianTRice@gmail.com on August 17, 2017, 05:45:58 AM
I can tell you about a failure, I bought two meanwell 3000/48 power supplies, I have not had a problem with the supplies but they are big and heavy and take up valuable real estate on the bike, anyway I made it about 100kms from home and found out that the diodes I bought off eBay were not up to the task of charging for a long period and they smoked , I was able to charge off the plug next to the evse, but sat around for four hours, I then bought the ThunderStruck Motors TSM 2500 and paid almost the same (not including labour) but haven't had a problem yet, the meanwells are for sale ::)

The TSM2500 is basically what Zero uses for their Charge Tank accessory, so it'll likely be rugged enough for any project. And at 11lbs, it's lighter than the Elcon 2500's 15lbs.
Title: Re: Questions on batteries and chargers
Post by: Psycopyro on August 25, 2017, 02:37:28 AM
I can tell you about a failure, I bought two meanwell 3000/48 power supplies, I have not had a problem with the supplies but they are big and heavy and take up valuable real estate on the bike, anyway I made it about 100kms from home and found out that the diodes I bought off eBay were not up to the task of charging for a long period and they smoked , I was able to charge off the plug next to the evse, but sat around for four hours, I then bought the ThunderStruck Motors TSM 2500 and paid almost the same (not including labour) but haven't had a problem yet, the meanwells are for sale ::)

Thanks for your feedback, Thanks for your subliminal message ^^ but I'm not ready to buy as I have to learn before doing something which i'm not confident with, for safety and money.