4-12v OBC vs 6-8v OBC

jerseyforlife · 05-03-2022, 03:55 PM

Ok so I work at a company that makes smart chargers for golf carts. On our listings, it says if you have 4-12v batteries you need to bypass the OBC but not with 6-8v. Is there that much of a difference between the OBC?

The people above me say you only need to bypass the obc for the 4-12v but Ive had quite a few customers (6-8v) call in complaining its not charging and after they do the bypass it starts charging. Obviously some of them were just a bad OBC but I find it difficult to believe all of them had a bad OBC. I also find it difficult to believe theres THAT much of a difference between an obc for 4-12v and one for the 6-8v batteries.

Fairtax4me · 05-03-2022, 05:48 PM

Many reasons why the OBC should be bypassed when using a smart charger. The OBC controls current output and voltage of the original Powerdrive charger. It does that with a SCR type circuit that is on the negative side of the charger output. Charger output is not sent straight to the battery pack, it has to go through the OBC first to get there.

Two main reasons to bypass.
1. The old charger failed, but the OBC was still working. Now it's only a matter of time until the OBC fails as well, at which point no charger is going to work because the OBC is between the charger and the battery pack.
2. The OBC failed, and no smart charger will work because the OBC is in the middle of the charge circuit.
For ANY smart charger to work properly, it should have a direct connection to the battery pack Main + and - posts. This can not be done unless the OBC is bypassed, even if the OBC is still functioning.
IMO, best practice is just to tell customers to bypass the OBC when using that charger. Doesn't matter what cart its on, if it has an OBC at all, bypass it.

jerseyforlife · 05-04-2022, 08:03 AM

I appreciate your response but that wasnt really my question. I do agree with you on the "if you have an OBC, bypass it" as thats my thoughts too but I was more wondering if theres a difference between the 4-12v obc compared to the 6-8v obc. Im trying to get evidence to show them that we should be telling customers to bypass the OBC no matter what the battery arrangement.

Fairtax4me · 05-04-2022, 08:40 AM

You may have to sweet talk the tech guys at Lester Electrical to find out any exact difference.
As far as hardware I'm not sure there is much difference. They both perform the same function. Any documentation that is available from Club Car is basically the same as far as operating and troubleshooting are concerned. And both are designed to be used with the same Powerdrive3 charger. There were a few variations of that charger but the biggest difference was the rectifier assembly.

Programming wise there may be a difference in that the 12v version is used with lower Ah batteries. Typically 140Ah Vs 170Ah for 8v packs. This could make a difference in the charge algorithm and how the OBC calculates capacity/energy usage for recharging. Since part of it's job is to monitor energy usage and recharge that amount. But exactly what the differences are in how it does that between a 12v pack vs an 8v pack, I don't know if anybody except the designers at Lester will know that. If there is some kind of info out there on the exact differences I would love to see it as well, just to understand more about them.

kgsc · 05-04-2022, 09:00 AM

Here is a link talking about it. https://www.buggiesgonewild.com/showthread.php?t=55785

SouthCo · 05-04-2022, 09:01 AM

I’m not sure why anyone would buy a smart charger and then let the OBC decide how much to charge the batteries. Doesn’t that defeat some of the reason of buying a smart charger…? If I’m the boss/higher up of a company who sells smart chargers you better believe I’m gonna tell my customers that our smart charger can do a better job of charging the batteries than the OBC and a non-smart charger…

Sent from my iPhone using Tapatalk

Volt_Ampere · 05-04-2022, 09:49 AM

A Smart Charger replaces the OBC function. The OBC was used to allow for a very cheap dumb charger. I always recommend that my buddies get a Smart Charger and ditch the OBC when they have charging / running problems due to a faulty OBC.

CP241 · 05-04-2022, 10:04 AM

I have worked in engineering departments of major electronics manufacturers and dealt with some of these type questions.

Bottom line is, whatever “magic” is happening in the 6x8v vs 4x12v is likely something Lester will not want to release. Much of that product spec is probably confidential because if they released their engineering documents, and software, anyone in the world could produce an exact copy of it with the same components, same quality, etc. but do it cheaper because they don’t have the NRE to cover for (non-refundable engineering costs).

Given this, and working with another suppliers product of which you have limited to no technical information, and you (and we) know causes issues then reverse your thinking. Instead of trying to prove to them that they’re different and why (which unless you know someone at Lester isn’t something you’ll ever answer) flip it on them. Show real world cases of where you’ve had problems with the OBC, keep documentation of a few cases. Then put the burden on them to prove why they are different. When they are also unable to do so, they’ll likely see the problems in the field and change their direction.

In your line of work, customer satisfaction and making things work right, and easily for a less technically inclined customer is more important than a hard headed engineer somewhere saying “it should work”. Much if what I did at my last job was real world validation of our parts instead of just letting the guys in the lab say “it passed the chamber, shotgun, etc tests. It’s good”. You wouldn’t believe the amount of stuff I find in real world that never presents in a lab.

jerseyforlife · 05-04-2022, 03:04 PM

That was part of the reason for my question, I have multiple cases of customers being told it "should work on your cart with 6-8v" but they get it and nothing works. Ive brought this up a few times to the higher ups and im told "its probably something with their cart then". To me that makes no sense, then if i ask why they only need to bypass the OBC with 4-12v, I get told "the algorithm is different". Im no electronics master but Ive taken a few years of electrical engineering so im not clueless but I cant see the OBCs being so different that we need to bypass one but not the other.

I know i could considerably reduce the amount of tech calls and reduce the warranties we do on club car chargers because if they have 6-8v and our charger doesnt work, we just send another hoping it will work (it usually dosent so they send it back and get a refund)

Fairtax4me · 05-04-2022, 04:09 PM

Some sales master decided it was better marketing to just say it works with the OBC and that draws in people thinking all they need to do is plug and play, because moving the two wires that are needed in order to bypass the OBC is too difficult.

Algorithm has nothing to do with it, when the OBC is broke, it's broke! Poke around here for OBC threads. Gotta be hundreds of them. Print them all and hand your people a book of all the different ways that the OBC fails.

05-03-2022, 03:55 PM	#1
jerseyforlife Not Yet Wild Join Date: Mar 2021 Location: Austin Posts: 4	4-12v OBC vs 6-8v OBC Ok so I work at a company that makes smart chargers for golf carts. On our listings, it says if you have 4-12v batteries you need to bypass the OBC but not with 6-8v. Is there that much of a difference between the OBC? The people above me say you only need to bypass the obc for the 4-12v but Ive had quite a few customers (6-8v) call in complaining its not charging and after they do the bypass it starts charging. Obviously some of them were just a bad OBC but I find it difficult to believe all of them had a bad OBC. I also find it difficult to believe theres THAT much of a difference between an obc for 4-12v and one for the 6-8v batteries.

05-03-2022, 05:48 PM	#2
Fairtax4me Bonafide Nincompoop Join Date: Dec 2015 Location: Charlottesburg Va Posts: 8,987	Re: 4-12v OBC vs 6-8v OBC Many reasons why the OBC should be bypassed when using a smart charger. The OBC controls current output and voltage of the original Powerdrive charger. It does that with a SCR type circuit that is on the negative side of the charger output. Charger output is not sent straight to the battery pack, it has to go through the OBC first to get there. Two main reasons to bypass. 1. The old charger failed, but the OBC was still working. Now it's only a matter of time until the OBC fails as well, at which point no charger is going to work because the OBC is between the charger and the battery pack. 2. The OBC failed, and no smart charger will work because the OBC is in the middle of the charge circuit. For ANY smart charger to work properly, it should have a direct connection to the battery pack Main + and - posts. This can not be done unless the OBC is bypassed, even if the OBC is still functioning. IMO, best practice is just to tell customers to bypass the OBC when using that charger. Doesn't matter what cart its on, if it has an OBC at all, bypass it.

05-04-2022, 08:03 AM	#3
jerseyforlife Not Yet Wild Join Date: Mar 2021 Location: Austin Posts: 4	Re: 4-12v OBC vs 6-8v OBC I appreciate your response but that wasnt really my question. I do agree with you on the "if you have an OBC, bypass it" as thats my thoughts too but I was more wondering if theres a difference between the 4-12v obc compared to the 6-8v obc. Im trying to get evidence to show them that we should be telling customers to bypass the OBC no matter what the battery arrangement.

05-04-2022, 08:40 AM	#4
Fairtax4me Bonafide Nincompoop Join Date: Dec 2015 Location: Charlottesburg Va Posts: 8,987	Re: 4-12v OBC vs 6-8v OBC You may have to sweet talk the tech guys at Lester Electrical to find out any exact difference. As far as hardware I'm not sure there is much difference. They both perform the same function. Any documentation that is available from Club Car is basically the same as far as operating and troubleshooting are concerned. And both are designed to be used with the same Powerdrive3 charger. There were a few variations of that charger but the biggest difference was the rectifier assembly. Programming wise there may be a difference in that the 12v version is used with lower Ah batteries. Typically 140Ah Vs 170Ah for 8v packs. This could make a difference in the charge algorithm and how the OBC calculates capacity/energy usage for recharging. Since part of it's job is to monitor energy usage and recharge that amount. But exactly what the differences are in how it does that between a 12v pack vs an 8v pack, I don't know if anybody except the designers at Lester will know that. If there is some kind of info out there on the exact differences I would love to see it as well, just to understand more about them.

05-04-2022, 09:00 AM	#5
kgsc Gone Wild Join Date: Dec 2009 Location: Aiken, SC Posts: 13,188	Re: 4-12v OBC vs 6-8v OBC Here is a link talking about it. https://www.buggiesgonewild.com/showthread.php?t=55785

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05-04-2022, 09:01 AM	#6
SouthCo Gone Wild Join Date: Sep 2009 Location: Maryland Posts: 569	4-12v OBC vs 6-8v OBC I’m not sure why anyone would buy a smart charger and then let the OBC decide how much to charge the batteries. Doesn’t that defeat some of the reason of buying a smart charger…? If I’m the boss/higher up of a company who sells smart chargers you better believe I’m gonna tell my customers that our smart charger can do a better job of charging the batteries than the OBC and a non-smart charger… Sent from my iPhone using Tapatalk

05-04-2022, 09:49 AM	#7
Volt_Ampere Gone Wild Join Date: May 2012 Location: Rio Verde, Az Posts: 7,192	Re: 4-12v OBC vs 6-8v OBC A Smart Charger replaces the OBC function. The OBC was used to allow for a very cheap dumb charger. I always recommend that my buddies get a Smart Charger and ditch the OBC when they have charging / running problems due to a faulty OBC.

05-04-2022, 10:04 AM	#8
CP241 Nincompoop village idiot Join Date: Apr 2018 Location: Michigan Posts: 9,690	Re: 4-12v OBC vs 6-8v OBC I have worked in engineering departments of major electronics manufacturers and dealt with some of these type questions. Bottom line is, whatever “magic” is happening in the 6x8v vs 4x12v is likely something Lester will not want to release. Much of that product spec is probably confidential because if they released their engineering documents, and software, anyone in the world could produce an exact copy of it with the same components, same quality, etc. but do it cheaper because they don’t have the NRE to cover for (non-refundable engineering costs). Given this, and working with another suppliers product of which you have limited to no technical information, and you (and we) know causes issues then reverse your thinking. Instead of trying to prove to them that they’re different and why (which unless you know someone at Lester isn’t something you’ll ever answer) flip it on them. Show real world cases of where you’ve had problems with the OBC, keep documentation of a few cases. Then put the burden on them to prove why they are different. When they are also unable to do so, they’ll likely see the problems in the field and change their direction. In your line of work, customer satisfaction and making things work right, and easily for a less technically inclined customer is more important than a hard headed engineer somewhere saying “it should work”. Much if what I did at my last job was real world validation of our parts instead of just letting the guys in the lab say “it passed the chamber, shotgun, etc tests. It’s good”. You wouldn’t believe the amount of stuff I find in real world that never presents in a lab.

05-04-2022, 03:04 PM	#9
jerseyforlife Not Yet Wild Join Date: Mar 2021 Location: Austin Posts: 4	Re: 4-12v OBC vs 6-8v OBC That was part of the reason for my question, I have multiple cases of customers being told it "should work on your cart with 6-8v" but they get it and nothing works. Ive brought this up a few times to the higher ups and im told "its probably something with their cart then". To me that makes no sense, then if i ask why they only need to bypass the OBC with 4-12v, I get told "the algorithm is different". Im no electronics master but Ive taken a few years of electrical engineering so im not clueless but I cant see the OBCs being so different that we need to bypass one but not the other. I know i could considerably reduce the amount of tech calls and reduce the warranties we do on club car chargers because if they have 6-8v and our charger doesnt work, we just send another hoping it will work (it usually dosent so they send it back and get a refund)

05-04-2022, 04:09 PM	#10
Fairtax4me Bonafide Nincompoop Join Date: Dec 2015 Location: Charlottesburg Va Posts: 8,987	Re: 4-12v OBC vs 6-8v OBC Some sales master decided it was better marketing to just say it works with the OBC and that draws in people thinking all they need to do is plug and play, because moving the two wires that are needed in order to bypass the OBC is too difficult. Algorithm has nothing to do with it, when the OBC is broke, it's broke! Poke around here for OBC threads. Gotta be hundreds of them. Print them all and hand your people a book of all the different ways that the OBC fails.