Bill-N Posted May 3, 2013 Report Share Posted May 3, 2013 The owners manual is mum on this point. Anyone tried it? Any gotcha's? Quote Link to comment Share on other sites More sharing options...
plus 3 golfer Posted May 3, 2013 Report Share Posted May 3, 2013 (edited) Good question. When you push the start button on the C-Max, the battery voltage does jump up to 14+ volts. But the question is how long does one really want to crank the other vehicle with the other vehicle's starter motor draw through the DC/DC converter. The converter is cooled by the HV battery cooling fans. From the workshop manual, the bold implies one can connect load to the battery terminals under the hood. -- "External customer loads must only be connected to the vehicle at the customer battery connection point. If an external customer load is connected at the negative battery post, the Battery Monitoring Sensor accuracy cannot be guaranteed. It is recommended that the Battery Monitoring Sensor pole clamp is not removed unless a battery replacement is required.Should the battery need to be isolated, this should be done by disconnecting the ground eyelet at the chassis ground." Also, the DC/DC converter is protected by a 30 A high side fuse and can provide 145 A of low side power: "The Direct Current/Direct Current (DC/DC) converter control module is protected by a 30 amp high voltage low current fuse located in the High Voltage Battery Junction Box. The Direct Current/Direct Current (DC/DC) converter control module steps the high-voltage down to a low-voltage (between 13 and 14.9 volts, depending on vehicle needs), providing power to the vehicle low-voltage battery systems. Depending on the vehicle and environmental conditions, the Direct Current/Direct Current (DC/DC) converter control module is capable of outputting as many as 145 amps to the 12-volt battery." So, I don't see a problem but I'm not going to try unless it's an emergency. :) Edited May 3, 2013 by Plus 3 Golfer obob and FoutsNC 2 Quote Link to comment Share on other sites More sharing options...
MikeB Posted May 4, 2013 Report Share Posted May 4, 2013 Good info from Plus 3. I'd add one additional thought: if you are going to jump start another vehicle with your C-Max, it might be best to use your battery to charge the other car battery, rather than using your battery to start the engine. We have plenty of juice available if delivered slowly, but not a great deal of cranking amps. So plug in the jumper cables and let the cars sit for a bit, rather than attempting immediately to start the 2nd engine. Quote Link to comment Share on other sites More sharing options...
jmckinley Posted May 4, 2013 Report Share Posted May 4, 2013 Just use your Stanley Simple Start to start the other car. Every C Max should be carrying some sort of emergency jumper battery. JAZ, obob and ScubaDadMiami 3 Quote Link to comment Share on other sites More sharing options...
seansrq11 Posted September 13, 2013 Report Share Posted September 13, 2013 I was able to jump start a my car with a bad battery to get it to the parts store to get a new one. I used my C-Max, just using the positive terminal that pokes out where a battery would normally be located. I could not see the battery per se because everything is sealed and tucked away on the compartment. Anyway, the trick was to keep the C-Max floored so that the ICE stayed on. After about 5 minutes it worked which is a long time but, that battery was d-e-a-d! Long story short, it is possible and C-Max is fine. CNCGeek and djc 2 Quote Link to comment Share on other sites More sharing options...
zhackwyatt Posted September 19, 2013 Report Share Posted September 19, 2013 I was able to jump start a my car with a bad battery to get it to the parts store to get a new one. I used my C-Max, just using the positive terminal that pokes out where a battery would normally be located. I could not see the battery per se because everything is sealed and tucked away on the compartment. Anyway, the trick was to keep the C-Max floored so that the ICE stayed on. After about 5 minutes it worked which is a long time but, that battery was d-e-a-d! Long story short, it is possible and C-Max is fine.The battery is in the back by the High-Voltage battery. Anyways, I jumped my Explorer, didn't require any flooring of the engine for me, but I wouldn't call it d-e-a-d either. :) Quote Link to comment Share on other sites More sharing options...
joc Posted January 26, 2015 Report Share Posted January 26, 2015 The last post here is 16 months old. Is there any new information, perhaps from Ford, about whether a C-Max can be used to jump start another vehicle? Would love to know the manufacturer's recommended solution... Quote Link to comment Share on other sites More sharing options...
fotomoto Posted January 26, 2015 Report Share Posted January 26, 2015 After reading a couple of horror stories from Prius owners getting the polarities wrong and frying very expensive computer modules, I won't do it unless it is a true emergency which I have yet to encounter. I've told folks stranded in parking lots, "I have an electric car and have an extremely high voltage battery." which they understood as a no. It's not the whole truth but it's not a lie either! ;) Instead of jumping from our hybrid(s), I used a battery charger with a 10amp boost setting on our last ICE vehicle that had an occasional dead battery. Quote Link to comment Share on other sites More sharing options...
Adrian_L Posted January 26, 2015 Report Share Posted January 26, 2015 (edited) The battery is in the back by the High-Voltage battery. That's true, but there are positive and negative terminals under the hood in front of the driver. They are probably just linked to the starting battery with 0 gauge wires. EDIT: while washing the car last weekend I noticed the said wires are fairly thin--probably 6 gauge at most. Edited February 13, 2015 by Adrian_L Quote Link to comment Share on other sites More sharing options...
wab Posted January 27, 2015 Report Share Posted January 27, 2015 Maybe this question answers a bigger question. Why does Ford use a "Starting" battery,which it doesn't need, in the Cmax? Quote Link to comment Share on other sites More sharing options...
ptjones Posted January 27, 2015 Report Share Posted January 27, 2015 (edited) That's true, but there are positive and negative terminals under the hood in front of the driver. They are probably just linked to the starting battery with 0 gauge wires. Maybe this question answers a bigger question. Why does Ford use a "Starting" battery,which it doesn't need, in the Cmax?CMAX uses 12v batt. to get the electronics and computers going and HVB to start the car. If you can't get electronics going you can't start the car, that is why it only needs that small 12v batt. to get the ICE going. :) Paul Edited January 27, 2015 by ptjones Quote Link to comment Share on other sites More sharing options...
wab Posted January 27, 2015 Report Share Posted January 27, 2015 Maybe this question answers a bigger question. Why does Ford use a "Starting" battery,which it doesn't need, in the Cmax? CMAX uses 12v batt. to get the electronics and computers going and HVB to start the car. If you can't get electronics going you can't start the car, that is why it only that small 12v batt. to get the ICE going. :) Paul My point exactly, why not use a "Deep Cycle" 12v, it would go A LONG WAY in hiding the DEAD 12V problem. Quote Link to comment Share on other sites More sharing options...
Adrian_L Posted January 27, 2015 Report Share Posted January 27, 2015 Would be interested to hear if anyone put an AGM deep cycle in there after repeated problems and what the result was. Quote Link to comment Share on other sites More sharing options...
homestead Posted January 27, 2015 Report Share Posted January 27, 2015 My point exactly, why not use a "Deep Cycle" 12v, it would go A LONG WAY in hiding the DEAD 12V problem.Don't need a deep cycle battery if everything is working as it should, mine has had no battery problems in almost 2 years since new.Let's not cover up the real problem with a bigger battery, instead find the culprit that is drawing excessive power and fix the problem. Quote Link to comment Share on other sites More sharing options...
jdbob Posted January 27, 2015 Report Share Posted January 27, 2015 The 12V battery in the Volt is an AGM battery, not sure if it's deep cycle or not. I noted it is rated at 60Ah which is quite a bit higher than in our cars. That picture was actually posted in a Tesla forum as they have to replace their 12V batteries often as well. In their case it's because the computers take a lot of power and are left on all the time, so periodically during the day it will recharge the 12V battery from the HV battery, resulting in many charge-discharge cycles. In our case it appears the problem is normally that although the computers in ours are supposed to shut down into a very low power state - sometimes they don't. Quote Link to comment Share on other sites More sharing options...
ptjones Posted January 27, 2015 Report Share Posted January 27, 2015 (edited) My point exactly, why not use a "Deep Cycle" 12v, it would go A LONG WAY in hiding the DEAD 12V problem.I posted a thread" Possible Solution for Dead Battery Problem" where I showed how to add another small 12v battery to storage compartment to increase 12v battery capacity by half again to minimize the possible dead battery problem. I tried find a larger battery for CMAX but couldn't find one that would fit. Don't need a deep cycle battery if everything is working as it should, mine has had no battery problems in almost 2 years since new.Let's not cover up the real problem with a bigger battery, instead find the culprit that is drawing excessive power and fix the problem.I agree this doesn't solve all cases or root problem for some people but might help until FORD finds all the possible problems. :) Paul Edited January 27, 2015 by ptjones Quote Link to comment Share on other sites More sharing options...
obob Posted January 28, 2015 Report Share Posted January 28, 2015 (edited) The owners manual is mum on this point. Anyone tried it? Any gotcha's? My sense is that if it were not OK, there would be warning messages at the terminals of the battery and the engine compartment and in the manual and it would be fuel for bad reviews by reporters, not to mention source of warranty service and potential loss of customer good will. Edited January 28, 2015 by obob Quote Link to comment Share on other sites More sharing options...
homestead Posted January 28, 2015 Report Share Posted January 28, 2015 I posted a thread" Possible Solution for Dead Battery Problem" where I showed how to add another small 12v battery to storage compartment to increase 12v battery capacity by half again to minimize the possible dead battery problem. I tried find a larger battery for CMAX but couldn't find one that would fit. I agree this doesn't solve all cases or root problem for some people but might help until FORD finds all the possible problems. :) PaulIt's possible Ford already found and fixed the problem by dumping Microsoft, doesn't help those with current cars though. Quote Link to comment Share on other sites More sharing options...
Adrian_L Posted January 28, 2015 Report Share Posted January 28, 2015 Don't need a deep cycle battery if everything is working as it should, mine has had no battery problems in almost 2 years since new.Let's not cover up the real problem with a bigger battery, instead find the culprit that is drawing excessive power and fix the problem. Yeah, and warranties and insurance are both a complete waste of money if everything is as it should be. Quote Link to comment Share on other sites More sharing options...
homestead Posted January 28, 2015 Report Share Posted January 28, 2015 Yeah, and warranties and insurance are both a complete waste of money if everything is as it should be.Ok, but I won't comment on that since that is not the topic. I hope folks with persistent battery problems will search for a dealership with technical experts interested in getting to the root cause and not give up on getting their problem fixed. Quote Link to comment Share on other sites More sharing options...
plus 3 golfer Posted January 28, 2015 Report Share Posted January 28, 2015 My sense is that if it were not OK, there would be warning messages at the terminals of the battery and the engine compartment and in the manual and it would be fuel for bad reviews by reporters, not to mention source of warranty service and potential loss of customer good will.Agree. I've jumped my Nissan with my C-Max using the under hood terminals - just used normal jump starting procedures except C-Max was put in "ready to drive" mode (ICE not running). No issues. ptjones 1 Quote Link to comment Share on other sites More sharing options...
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